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StuartR
23-May-2018, 12:27
Hello all. I am looking to move to 8x10, and I was looking to shop for lenses. I generally make large enlargements (regularly 1mX80cm, and right now up to 150x190cm), and I have been very lucky with two Schneider lenses on 4x5...a 110mm Super Symmar XL and a 210mm APO Symmar L. I bought two 150mm APO Sironar S lenses and one 210mm APO Sironar S lens, and none of them seem to be better...one of them is most certainly worse. I do not know if I am just unlucky in buying on the secondary market, but I have seen printed work from a friend's 150mm APO Sironar S, and know it to be a superb lens. In any case, I am looking to get a good standard lens in the 240mm-360mm focal length for 8x10. Generally I would try to get the best lens possible as I enlarge very big, though I realize that this is less of a strain from an 8x10 neg. I will likely contact print in the darkroom, and scan using drum scans for exhibitions, or stitched camera scans from medium format digital.
Looking at ebay and the like, the 300mm Sironar N can be had for a few hundred dollars in some cases, but the 300mm Apo Sironar S is now usually over 3000 dollars used, or 4600 dollars for a new one via special order. I am curious if anyone who has used both can comment on the qualitative differences for general use in the field. I understand the S is optimized better for studio work than the N, but that is not my main concern. I am mostly interested in use on subjects in the field, likely from about 2m to infinity. Finally, how would the N version compare to a comparable offering from Schneider or Nikon? I am sorry, as I know this is a vague and subjective, but at this point I do not want to spend an extra 2500 dollars on a lens on the chance that it MIGHT be sharper, depending on sample variation etc etc. The extra coverage would be nice, but not totally required.

Thanks very much!
Stuart

Ken Lee
23-May-2018, 12:52
If you don't need a lot of coverage an APO Nikkor or Ronar are likely just as sharp and are more portable, affordable and available than a Sironar S. The 240mm, 300mm or 360mm Fujinon A series will also match the Sironar S in resolution and coverage but will be smaller, lighter, etc. A 300m Nikkor M will do very nicely also. (My 200mm Nikkor M matches the resolution of my 150mm APO Sironar S)

Have a look at Arne Croell's lens tests (http://www.arnecroell.com/lenstests.pdf): you'll see that with regard to resolution most really good modern lenses are about the same: really good. There are no offerings which stand head-and-shoulders above the rest.

Given the sag of 8x10 sheet film and the comparatively shallow depth of field which often necessitate small taking apertures and long exposures, any one of those lenses should serve well and differences in image quality will be hard to discern.

Oren Grad
23-May-2018, 13:01
Good to see you dropping by - I've enjoyed your posts over at GetDPI!

Back in the day, both Schneider and Rodenstock provided data sheets with MTF curves for their respective lenses. I happen to have the sheets for both the Apo-Symmar L and the Apo-Sironar-S in the 300mm focal length. Unfortunately, the only directly comparable MTF data among the respective chart sets are for the 1:10 ratio, not infinity. That said, what struck me in looking at them was how similar the curve sets are. What this says to me is that any hair-splitting one might try to do based on the specifications is likely to be overwhelmed by sample variation, arising from whatever combination of manufacturing variation and differences in how the respective samples have been banged around in the field over the years. Unfortunately, this means the only way to be safe in making a purchase is to buy from a source that will allow a return if the specific sample isn't up to snuff. More unfortunately, that is very difficult to do in today's market, and especially with these two now fairly exotic and expensive lenses.

FWIW, I have most of the focal lengths in both the (Apo-)Sironar-N and Apo-Sironar-S lines, though in the 300mm focal length I have only the N. I have used them primarily to make negatives for contact printing, so unfortunately cannot comment from experience about enlargement. However, FWIW, I am very satisfied with my sample of the 300 N, and I think that given the disproportionate cost of the 300 S in today's market, it would be rational to purchase an N, run some tests and see whether the results are satisfactory for your needs. If you don't like it, you will have much less money on the line, and it will also likely be easier too to sell it on.

Sal Santamaura
23-May-2018, 14:31
I strongly recommend you read through this thread, especially starting with my post #163 from two years ago:


http://www.largeformatphotography.info/forum/showthread.php?71322-f64&p=1321449&viewfull=1#post1321449

While I have no direct experience with the 300mm Apo Sironar S, Lenny, who I purchased my 300mm Nikkor W from, does. I do own a 135mm Apo Sironar S. With distant subjects and using f/22, it's less sharp than the 135mm Apo Sironar N and 135mm CM-Fujinon W I also have.

As always, sample variation must be considered when evaluating lenses. Good luck.

Pere Casals
23-May-2018, 15:07
I've a Sironar-N 300 MC, the APO Sironar-N 300 is mostly the same, not exactly.

I've never seen a Sironar-S...

In theory ED glass (in the S) helps eliminate secondary chromatic aberration (green-magenta color fringes), so (also in theory) the S should deliver slightly better "microcontrast" in fine textures after a high enlargement, but this would not (IMHO) improve general contrast, because modern multicoatings are the perfection.

ED glass has a lower index of refraction so elements are more curved for the same focal length, and I guess this is related to the weight increase in the S version.

My guess is that if we can notice a difference (in some conditions) it would be more related to microcontrast that to the general contrast.


The S is optimized from 1:10 magnification to infinite, while the N is optimized from 1:20 to infinite. The S is made with some ED glass while the N not. The S has an slightly larger circle. The N may be slightly sharper in the 4x5 corner (see MTF graphs from Rodenstock), while the S may be sharper if going farther than that.

Both the N and the S can generate flare, not because the lens itself but because the very large circle may illuminate (and reflecting in) the bellows more than the film sheet, so a perfect job requires a front hub to trim the 425/450 too large circle to the required 8x10 size.

IMHO a sound 810 shot depends more on the photographer than in if the glass is S or N. Avoiding vibrations (wind), camera alignment, film flatness, using right aperture vs DOF, etc may be way more critical.

Of course the S is a better lens, but I guess that it can be really difficult to notice it, for example if using TMY (instead TMX) you have a sharpness limitation from film that won't allow to see difference in the negative.

I'd say the S is not more contrasty than the N, IMHO any lack of contrast may be related to reflections inside the bellows because the huge circles.

What's about sharpness, even if placing the nose on a 2m print I guess we would not see the limits of an N 300.

My N 300 came with some fungus, but this was solved with no performance loss, I guess. I don't know how a lens can be better, in a way that I think that the glass is better than me.

Bob Salomon
23-May-2018, 16:04
I've a Sironar-N 300 MC, the APO Sironar-N 300 is mostly the same, not exactly.

I've never seen a Sironar-S...

In theory ED glass (in the S) helps eliminate secondary chromatic aberration (green-magenta color fringes), so (also in theory) the S should deliver slightly better "microcontrast" in fine textures after a high enlargement, but this would not (IMHO) improve general contrast, because modern multicoatings are the perfection.

ED glass has a lower index of refraction so elements are more curved for the same focal length, and I guess this is related to the weight increase in the S version.

My guess is that if we can notice a difference (in some conditions) it would be more related to microcontrast that to the general contrast.


The S is optimized from 1:10 magnification to infinite, while the N is optimized from 1:20 to infinite. The S is made with some ED glass while the N not. The S has an slightly larger circle. The N may be slightly sharper in the 4x5 corner (see MTF graphs from Rodenstock), while the S may be sharper if going farther than that.

Both the N and the S can generate flare, not because the lens itself but because the very large circle may illuminate (and reflecting in) the bellows more than the film sheet, so a perfect job requires a front hub to trim the 425/450 too large circle to the required 8x10 size.

IMHO a sound 810 shot depends more on the photographer than in if the glass is S or N. Avoiding vibrations (wind), camera alignment, film flatness, using right aperture vs DOF, etc may be way more critical.

Of course the S is a better lens, but I guess that it can be really difficult to notice it, for example if using TMY (instead TMX) you have a sharpness limitation from film that won't allow to see difference in the negative.

I'd say the S is not more contrasty than the N, IMHO any lack of contrast may be related to reflections inside the bellows because the huge circles.

What's about sharpness, even if placing the nose on a 2m print I guess we would not see the limits of an N 300.

My N 300 came with some fungus, but this was solved with no performance loss, I guess. I don't know how a lens can be better, in a way that I think that the glass is better than me.
So you are assuming with no experience! You do know what assume means?

Greg
23-May-2018, 16:24
I would seriously consider either a 305mm or 355mm G-Claron in a Copal shutter. I use them on my 8x10 and love them, but then I make contact prints. While back I had one 8x10 inch negative that a way off-center 4x5 inch section of it was way more interesting than the whole image on the negative. Cut out that 4x5 inch section and enlarged it to 20x24 inches (largest print size for me to process easily in my darkroom's sink). The resulting image was tack sharp on the print.

Suggest you do some research on Edward Burtynsky. I believe that he uses or used a 5x7 camera for his color work. I've seen some of his huge, wall sized, enlargements and they are tack sharp when I viewed them up close. Clyde Butcher is another photographer to find out what lenses he used for his B&W work.

StuartR
23-May-2018, 18:25
Thanks everyone. If cost and logistics were not an issue, I would try them all. I do think sample variation is very real and likely more important than the differences between makers. I have had access to three 150mm APO Sironar S lenses for testing...one is clearly out of spec, one is sharp in the center but slightly soft in the edges, but more so on one side than the other, and the third is impressively sharp. I plan on sending my two to Rodenstock for service to see if they can be fixed. My 210mm APO Symmar L is better than the 210 Sironar S I acquired which is in nearly mint condition. It is very good, but the Schneider seems better in my basic tests and my workflow. That is not what common wisdom would seem to suggest. But based on being underwhelmed by three Sironar S lenses, I am not looking to shell out 4500 dollars for one.

Greg -- I am nearly certain Burtynsky is using a 100mp back...at least for the more recent aerial work. That is all I have seen in person, but it looked distinctly digital. Good, but digital. I know some other 8x10 shooters I can ask about lenses, but to be honest, people on forums like this generally know the lenses better than most artists (unless they are an artist posting on here). Generally they get what they can afford and just use it. Not bad advice, of course, but since I do not have anything yet, I would rather start with a "forever" lens. I bought my 110mm and 210mm in 2004, and since then have not really felt the need for different lenses in that focal length (the 210 Sironar S was just to try...I was going to sell whichever I liked less, it was not really out of dissatisfaction with the Schneider). My goal here is to get a similarly great lens that I just don't need to think about.

Pere Casals
23-May-2018, 18:46
So you are assuming with no experience! You do know what assume means?

Bob, in what I'm wrong ?

The resolving power of both is well specified by Rodenstock in the MTF charts. Rodenstock provided very accurate information about that, allowing the sample to sample variation as always...

Hasn't the S (slightly) less secondary chromatic aberration because the ED?

Any other technical S vs N difference that can be seen in the image?

General contrast has to be the same, but microcontrast of the S has to be slightly higher. True or not ?

Bob Salomon
23-May-2018, 18:59
Bob, in what I'm wrong ?

The resolving power of both is well specified by Rodenstock in the MTF charts. Rodenstock provided very accurate information about that, allowing the sample to sample variation as always...

Hasn't the S (slightly) less secondary chromatic aberration because the ED?

Any other technical S vs N difference that can be seen in the image?

General contrast has to be the same, but microcontrast of the S has to be slightly higher. True or not ?

I suggest that you examine the coverage in the MTF curves and go out and actually shoot with one. Then you can actually speak from experience rather then from assumptions!

Pere Casals
23-May-2018, 19:25
I suggest that you examine the coverage in the MTF curves and go out and actually shoot with one. Then you can actually speak from experience rather then from assumptions!

Bob, I cannot access an S, and in my location it is not possible to hire that kind of glass. So I've to guess from my N and from technical info.

I examined such coverage, graphs say that, regarding resolving power, the N is a perfect lens for 810 jobs, with the S having 23mm larger specified circle. MTFs show that no difference will be seen in practical photography because resolving power.

In the other hand we have ED glass in the S. To me the Extra Low Dispersion has a particular footprint in a plasmat, and this has to be the only practical difference. I'm I wrong in that ?

An S in good hands: https://www.flickr.com/photos/peterdegraaff/16097511180/in/photolist-dtVeC2-q5vGKa-bCZ1by-65g3Mv-qwtXfd-64gY12-qtyMyq-5TrMTJ-qkrsDD-rijxm9-5LVYbj-bzyS48-q9j85d-bn8sPx-qq4ezz-rjDQyA-8cLtyg-73Kiir-qTKmtU-sfNRhD/

Bob Salomon
23-May-2018, 19:32
Bob, I cannot access an S, and in my location it is not possible to hire that kind of glass. So I've to guess from my N and from technical info.

I examined such coverage, graphs say that, regarding resolving power, the N is a perfect lens for 810 jobs, with the S having 23mm larger specified circle. MTFs show that no difference will be seen in practical photography because resolving power.

In the other hand we have ED glass in the S. To me the Extra Low Dispersion has a particular footprint in a plasmat, and this has to be the only practical difference. I'm I wrong in that ?

An S in good hands: https://www.flickr.com/photos/peterdegraaff/16097511180/in/photolist-dtVeC2-q5vGKa-bCZ1by-65g3Mv-qwtXfd-64gY12-qtyMyq-5TrMTJ-qkrsDD-rijxm9-5LVYbj-bzyS48-q9j85d-bn8sPx-qq4ezz-rjDQyA-8cLtyg-73Kiir-qTKmtU-sfNRhD/

Have you looked at the distortion curves, the fall off curves, the color curves? And I believe that you are misreading the MTF curves. Check the numbers for the coverage carefully on the curves.

Leigh
23-May-2018, 20:37
I had standardized on the APO-Sironar-N series of lenses for several years.
I had every focal length made in that series except the longest one.

Then I had a chance to pick up an APO-Sironar-S of 150mm (or 180mm, don't remember).

I ran some comparisons between -N and the -S of the same focal length.
My conclusion was that the -S was somewhat better, looking at the resulting prints.
Other folks could see the difference also.

So I ended up standardizing on the -S series.
I sold off my -N lenses and bought a full set of the -S lenses.
I've never regretted that choice. The -S lenses are superb.

- Leigh

asf
23-May-2018, 21:45
In every length I've used the Rodenstock N and S the S is better, especially for color
The 135, 180 and 240 S are very much worth the money

The 300 I can't say is worth the extra - the 300 Symmar S MC and Apo Symmars I've used in that length have been more to my liking
My guess is the relatively high used prices on the 300 Rodenstock S is a result of sellers pushing it as an 11x14/ULF lens

I don't like the way the Apo Symmar L renders images

My advice would be to get a good condition late 300 Symmar S MC and test it, they can be had for $500 or less if you look
8x10 contacts are very different from enlarged 4x5 prints

ic-racer
24-May-2018, 04:54
Just about any 300mm plasmat should be fine. You negative sharpness will be determined by selected f-stop, focal spread and your camera support platform.

Bernice Loui
24-May-2018, 08:03
Published MTF curves are often calculated, not from actual lens test with acceptable limits for individual production lens variations.

Keep in mind mural sized prints have been made by AA and many others in the past using non-Plasmat lenses with more than acceptable results. It might be good to simply purchase a 300mm or 12" lens of preference then run some test to determine performance under actual image making conditions. This will help reveal the performance of that individual lens under your image making conditions. IMO, Plasmats as a group are far more similar than different regardless of the marketing hype.

There are and always will be variations to individual lens performance. With modern lenses, these variations can be smaller, but still subject to the realities that can happen to any optic. This is why testing a specific individual lens under your image making conditions with a right of return for any lens of significant $ is important.

For 8x10, there will be more struggle with film flatness, taking aperture, camera stability and more. These factors will tend to reduce the significant of perceived lens differences. These are the very real problems that makes 8x10 a problem film format to achieve optimal imaging performance.


Bernice

asf
24-May-2018, 08:21
There are and always will be variations to individual lens performance. With modern lenses, these variations can be smaller, but still subject to the realities that can happen to any optic. This is why testing a specific individual lens under your image making conditions with a right of return for any lens of significant $ is important.

For 8x10, there will be more struggle with film flatness, taking aperture, camera stability and more. These factors will tend to reduce the significant of perceived lens differences. These are the very real problems that makes 8x10 a problem film format to achieve optimal imaging performance.

Bernice

This exactly

Camera stability is extremely important - proper head and tripod are essential
Also film holders can make a difference

I've never liked how any Sironar N series lens has rendered images, I've liked how all Apo Sironar S series lenses have, some more than others
For 8x10, except for the 240 S, I decided the Apo Sironar S line wasn't worth it and have used Schneiders instead (for 300 and 360, Apo Ronar for 480)

*Nothing wrong with any Sironar N lens I've tried, they just weren't for me, completely subjective opinion

Eric Leppanen
24-May-2018, 11:14
During my 8x10 shooting days, I used a wide variety of plasmats including the 240, 300 and 360 Sironar-S; 300 Sironar-W; 360 APO Symmar; and 210 and 480 APO Symmar L. I've also used a variety of f/9 lenses including the 240, 300 and 360 Fuji A; 240 Germinar W; and 300 Nikon M.

Since my 8x10 landscape and external architecture field work was almost all shot at diffraction limited apertures, differences in sharpness and resolution among all these lenses were minimal within rated image circles. There were some contrast and rendering differences but these usually had little impact following post-processing in Photoshop. In their own way these are all fine lenses. I did prefer f/5.6 lenses when feasible for the way images snapped into focus on the ground glass, and for use in low light.

For my 8x10 normal lens I standardized on the 300 Sironar-S, because it had the largest image circle of the 300mm plasmats (aside from the huge 300 Sironar-W, which I also briefly used), and also its rear element was small enough so that the lens could be mounted on a Technika lens board (making storage a bit easier). When the light is changing quickly in the field and you are applying movements and hustling to get the shot, the last thing I want to worry about is coverage vignetting. The Sironar-S worked great both at close range (3-4 feet) and infinity. It was my workhorse 8x10 lens and I was very happy with it.

Regarding pricing differences, I think the Sironar-S line is generally regarded as LF best-in-class among plasmats (large coverage; performance at open apertures; Kerry Thalmann "Future Classic"; etc.), and as such is commanding (rightfully or wrongfully) a massive premium. Also 8x10 pricing for sought-after lenses has skyrocketed in recent years; at one point a decent 300 Sironar-S could be purchased for around $1,300 on Ebay, now the prices are over $3,000.

If you don't need a lot of coverage and expect to shoot at diffraction limited apertures, you have many more options. If I were shopping for a 300mm 8x10 lens today, I would give a good look at a Fuji 300 CM/W (even though I have never shot one), because Fuji lenses in generally are very sharp, and the CM/W is a modern top-of-the-line design that costs a fraction of the Sironar-S.

But if you have a varied number of shooting scenarios and want the lens that provides the most capability over the most circumstances, then you are left with the Sironar-S. That is why it costs so much.

Pere Casals
24-May-2018, 12:08
Have you looked at the distortion curves, the fall off curves, the color curves? And I believe that you are misreading the MTF curves. Check the numbers for the coverage carefully on the curves.

Well, from the curves we have nearly the same. These curves do not explain any practical difference in the images, beyond the slightly larger circle of the S. Practically same fall off, same resolving power, same distorsion amount, 0.5% max both, in one case it's barrel type and pincushion in the other.

I don't say that we cannot see a difference in a side by side shot, but specified technical performance is matching.

178564

At 20 lp/mm the S has an slightly higher modulation transfer, but IMHO this cannot be perceived by human sight, some difference should be there, as perceived by experienced users, but this is not told by the curves.

IMHO that slightly better transfer in high lppmm could be because the Extra Low Dispersion

Bob Salomon
24-May-2018, 12:34
Well, from the curves we have nearly the same. These curves do not explain any practical difference in the images, beyond the slightly larger circle of the S. Practically same fall off, same resolving power, same distorsion amount, 0.5% max both, in one case it's barrel type and pincushion in the other.

I don't say that we cannot see a difference in a side by side shot, but specified technical performance is matching.

178564

At 20 lp/mm the S has an slightly higher modulation transfer, but IMHO this cannot be perceived by human sight, some difference should be there, as perceived by experienced users, but this is not told by the curves.

IMHO that slightly better transfer in high lppmm could be because the Extra Low Dispersion

You really need to learn how to read the curves! They are different!

StuartR
24-May-2018, 19:25
Can you enlighten us, Bob (or at least me!)? I know the basics of MTF charts, but I am not an expert. I see that there are some differences in contrast, and the S seems a bit better in the MTF, but to my untrained eye it does not look particularly dramatic as Pere says. At the working aperture of 22, it seems as though the Sironar S has about 5% more contrast at the 20lpm level, but otherwise it looks pretty comparable to me. What is your interpretation?

Bob Salomon
24-May-2018, 19:34
Can you enlighten us, Bob (or at least me!)? I know the basics of MTF charts, but I am not an expert. I see that there are some differences in contrast, and the S seems a bit better in the MTF, but to my untrained eye it does not look particularly dramatic as Pere says. At the working aperture of 22, it seems as though the Sironar S has about 5% more contrast at the 20lpm level, but otherwise it looks pretty comparable to me. What is your interpretation?

You should be able to go to the Rodenstock Precision Optical Page at the Qioptiq web site and download the Rodenstock paper on reading the curves. If not, Dan should have it on his site.

Leigh
24-May-2018, 19:42
You should be able to go to the Rodenstock Precision Optical Page at the Qioptiq web site and download the Rodenstock paper on reading the curves.
Nope. Not there.

- Leigh

Bob Salomon
24-May-2018, 19:57
Nope. Not there.

- Leigh

Then this may help, but note, they talk about LINES PER MM, RODENSTOCK CURVES ARE FOR LINE PAIRS PER MM!

Oren Grad
24-May-2018, 20:13
I have posted a new sticky thread at the top of the Lenses subforum with documents from Zeiss and Schneider that talk about how to understand MTF.

http://www.largeformatphotography.info/forum/showthread.php?146212-How-to-understand-MTF

Pere Casals
24-May-2018, 23:44
read the curves! They are different!

Bob, Rodenstock provided excellent and accurate technical information about their glasses, but as they were serious they could not provide reliable MTF graphs at 40 or 60 cycles/mm for Sironar 300 versions, this is because the sample to sample variation or the ultimate performance at extintion variability.

IMHO a significative difference is not seen at 20cycles/mm, and contrast at 2.5 cycles/mm proves that "general" contrast is the same.

But the S has luxurious ED in it, that's not a joke, allowing the design working perfect from 1:10, and probably having better sample average at 40 cycles/mm graphs, but at 40 c/mm then we enter in the sample variation realm, so a serious manufacturer was not to deliver those graphs in what perhaps we would see a difference.

The N vs S debate has been seen a lot of times, any newcomer (like me) asks or searchs that at one point.

Sadly those threads lacked a single side by side sample, and also little was said about the role of ED glass in the S.


Brochures: https://onedrive.live.com/?id=8D71BC33C77D1008%21324&cid=8D71BC33C77D1008

Bob Salomon
25-May-2018, 04:23
Bob, Rodenstock provided excellent and accurate technical information about their glasses, but as they were serious they could not provide reliable MTF graphs at 40 or 60 cycles/mm for Sironar 300 versions, this is because the sample to sample variation or the ultimate performance at extintion variability.

IMHO a significative difference is not seen at 20cycles/mm, and contrast at 2.5 cycles/mm proves that "general" contrast is the same.

But the S has luxurious ED in it, that's not a joke, allowing the design working perfect from 1:10, and probably having better sample average at 40 cycles/mm graphs, but at 40 c/mm then we enter in the sample variation realm, so a serious manufacturer was not to deliver those graphs in what perhaps we would see a difference.

The N vs S debate has been seen a lot of times, any newcomer (like me) asks or searchs that at one point.

Sadly those threads lacked a single side by side sample, and also little was said about the role of ED glass in the S.


Brochures: https://onedrive.live.com/?id=8D71BC33C77D1008%21324&cid=8D71BC33C77D1008

Search for the Rodenstock brochure that introduced the S and there you will find side by side comparisons of the S and the N.

Pere Casals
25-May-2018, 05:25
Search for the Rodenstock brochure that introduced the S and there you will find side by side comparisons of the S and the N.

Thanks Bob, I cannot find that brochure... is there any link to it ?

Ken Lee
25-May-2018, 05:34
http://www.kennethleegallery.com/images/forum/3Sironars.jpg

Here's a diagram which shows the difference between the 3 different 150mm Sironars, the N, the S, and the W. I don't remember who made it.

Performance varies as we move away from the center of coverage. The S and N compete for best sharpness until we approach the extremes of coverage. The N drops off first while the W drops off last.

As Bernice pointed out, this may be a theoretical plot, not based on empirical testing. I presume we can extrapolate a similar result for the 300mm series.

Ari
25-May-2018, 06:20
Sturart, as "asf" pointed out, much of the results you're seeking depends on technique and good supporting equipment, and if you make a living from this, the right gear is crucial.
I've seen significant differences by switching over to Toyo film holders, which are harder to find and more expensive, but they're much more consistent than Fidelity or Lisco holders.
Same goes for tripod and head, I look for repeatable, trustworthy gear that works day in and day out.
Finding the lens appropriate to your work is another step, and there's some good advice here.
My "forever" lens is a Cooke XVa; after a lot of testing and shooting, I found the XVa to have superior contrast, a special sharpness/smoothness, which give it a very unique look. This applies to colour and B&W.
It costs about the same as a new 300mm Apo Sironar-S, maybe a bit less, but a significant advantage is that it's a convertible lens, so you can use 300mm, 460mm and 646mm focal lengths, and they're all excellent performers.

Bob Salomon
25-May-2018, 06:34
http://www.kennethleegallery.com/images/forum/3Sironars.jpg

Here's a diagram which shows the difference between the 3 different 150mm Sironars, the N, the S, and the W. I don't remember who made it.

Performance varies as we move away from the center of coverage. The S and N compete for best sharpness until we approach the extremes of coverage. The N drops off first while the W drops off last.

As Bernice pointed out, this may be a theoretical plot, not based on empirical testing. I presume we can extrapolate a similar result for the 300mm series.

MTF curves, not FTM!! But since the OP appears to be French maybe they reverse the letters!

Pere Casals
25-May-2018, 06:40
this may be a theoretical plot, not based on empirical testing.

Ken, IMHO this is not a test, just the curves in the datasheets from rodenstock copied and overlaped.

For the 150mm it shows the N sharper than the in the 4x5 corner, but the S being better farther. The graphs of the 300mm versions do not show that effect, being the S always better.

Bob Salomon
25-May-2018, 06:53
Ken, IMHO this is not a test, just the curves in the datasheets from rodenstock copied and overlaped.

For the 150mm it shows the N sharper than the in the 4x5 corner, but the S being better farther. The graphs of the 300mm versions do not show that effect, being the S always better.

How did you determine that? The green S curve starts higher then the N curve at the center, which is the point where the line starts on the left side and extends further and higher to the right which would be the edge of the image area.

Sal Santamaura
25-May-2018, 07:46
While the 'discussion' about MTF comparison continues, it's valuable to note that Rodenstock's design for and curves of the N series are based on 1:20 magnification, while those for its S series are based on 1:10. In my experience, that difference is evident when photographing subjects close to infinity, with the N being sharper, at least in the central field with my samples.

Bernice Loui
25-May-2018, 09:03
Keep in mind the modern Plasmat was intended to be a general purpose lens, essentially jack of all trades-master of none.

-Larger image circle is a myopic criteria for gauging overall lens performance.
-More line pairs per mm or lines per mm (which are NOT the same metric) is another myopic criteria for gauging overall lens performance.
-Higher contrast is another myopic criteria for gauging overall lens performance.
-APO, what does this really mean, axial or lateral color correction to what dimensions for what wavelengths over where on the optic's designed image circle. APO designation is NOT simple.
-What about color balance of a specific lens?
-Glass types used is mostly irrelevant as image results is far more important.
-There are inherent limitations to any given lens design, Plasmats will always have a given set of design trade-offs bad or good.
-Lens designers tend to impress their idea of what is ideal for a specific lens design should achieve and how to achieve it.
-There will be performance variations for a individual lens. While modern lenses can be remarkably consistent, variations will be found in any given individual lens.

Image making needs might be better served by selecting a more specialized optic for a specific image making need. At some point in discussions like this, there comes a time when all this intellectual and academic chatter must stop and images made, what is the goal of photography and expressive image making art?

Bottom line, only way to know if a specific lens can become a good image making tool for a specific image maker is to own it, use it lots, get to know it's problems and offerings over an extended period of time. If the specific lens does not meet the needs of the image maker, move on to another lens and keep at this until the keepers are in hand.


Bernice

Oren Grad
25-May-2018, 09:03
While the 'discussion' about MTF comparison continues, it's valuable to note that Rodenstock's design for and curves of the N series are based on 1:20 magnification, while those for its S series are based on 1:10.

What Sal said. To put it slightly differently, the MTF curves provided by Rodenstock for the N series are at 1:20 and the MTF curves provided for the S series are at 1:10, reflecting their respective design optimizations. So it's not valid to superimpose the curves and try to draw definitive fine distinctions between the lenses on that basis, nor is it possible to draw definitive fine distinctions about infinity performance based on the MTFs for closer work. (FWIW, and to their great credit, Schneider provided MTF curves at three different magnifications for each lens.)

Beyond that, the curves that are provided by both Schneider and Rodenstock for their plasmat series don't go beyond 20 lp/mm, so if one is worried about very big enlargements and critical viewers, all bets are off. If one has critical requirements that are not directly addressed by the supplied data, there is unfortunately no substitute for testing the candidate lens(es) directly. Even if the data are directly on point, there is still the problem of possible sample variation. Unfortunately, in today's market it's hard to lay one's hands on some of these lenses for testing purposes. But that's the reality we have to deal with.

Oren Grad
25-May-2018, 09:09
As Bernice pointed out, this may be a theoretical plot, not based on empirical testing. I presume we can extrapolate a similar result for the 300mm series.

There is a similar multicolor plot floating around with the 10 lp/mm curves for the N, S and W in the 300mm focal length, but I'm not going to post it as it's impossible to tell from the labeling whether the curves were measured at the same magnification or simply copied from Rodenstock's literature, in which case it would be apples vs oranges - 1:10 for the S and W but 1:20 for the N. The same problem applies to the chart you've posted.

Pere Casals
25-May-2018, 15:17
How did you determine that? The green S curve starts higher then the N curve at the center, which is the point where the line starts on the left side and extends further and higher to the right which would be the edge of the image area.

The 45 corner is at 76mm...

Red vertical bar shows the 45 corner point on the 150mm lens MTF, the green bars show the range were the N is better than the S, and this is the 45 corner.

That comes from Rodenstock brochures, https://onedrive.live.com/?id=8D71BC33C77D1008%21324&cid=8D71BC33C77D1008

The 112, 127 and 136 values (in blue, green, red) are the ranges in the Rodenstock graphs, that man used those values to stretch the curves from datasheets to be placed in the same scale...
178607

... and yes, if performing shift-rise then the Sironar S 150 wins... and the 150 S also allows a decent 57 shot...

Bob Salomon
25-May-2018, 15:21
The 45 corner is at 76mm...

Red vertical bar shows the 45 corner point, the green bars shows the range were the N is better than the S, and this is the 45 corner.

That comes from Rodenstock brochures, https://onedrive.live.com/?id=8D71BC33C77D1008%21324&cid=8D71BC33C77D1008

The 112, 127 and 136 values (in blue, green, red) are the ranges in the Rodenstock graphs, that man used those values to stretch the curves from datasheets to be placed in the same scale...178607
You do know that the graph is half of the coverage of the lens, not the full coverage of the lens?

The only answer to your question is to go out and shoot with the lens, weather you have to borrow one, rent one or buy one. You are not going to understand how they perform with your scale nonsense!

StuartR
25-May-2018, 15:27
Sturart, as "asf" pointed out, much of the results you're seeking depends on technique and good supporting equipment, and if you make a living from this, the right gear is crucial.
I've seen significant differences by switching over to Toyo film holders, which are harder to find and more expensive, but they're much more consistent than Fidelity or Lisco holders.
Same goes for tripod and head, I look for repeatable, trustworthy gear that works day in and day out.
Finding the lens appropriate to your work is another step, and there's some good advice here.
My "forever" lens is a Cooke XVa; after a lot of testing and shooting, I found the XVa to have superior contrast, a special sharpness/smoothness, which give it a very unique look. This applies to colour and B&W.
It costs about the same as a new 300mm Apo Sironar-S, maybe a bit less, but a significant advantage is that it's a convertible lens, so you can use 300mm, 460mm and 646mm focal lengths, and they're all excellent performers.

Thanks Ari, that is helpful info. I am pretty aware of the importance of the whole imaging chain. I use Toyo holders in 4x5, and plan on using them and Chamonix for 8x10 as well. I have a Really Right Stuff TVC-33 tripod and a BH55 head, though lately I have taken to mounting my Ebony directly on the leveling head. A heavy Ries or heavier RRS or Gitzo tripod might be called for, but I will see how I do with the TVC-33 first. It has served me well for at least seven years now with everything from 35mm to 4x5. Thanks as well for the idea regarding the Cooke. I have heard a lot of people talk about these lenses, but I have not seen anything about how they actually perform. Are they more orientated towards a smooth aesthetic, or sharpness? Given that I am mostly doing landscape work at small apertures, sharpness is more important to me than "glow" or bokeh, not that lens character is unimportant...

StuartR
25-May-2018, 15:30
Thank you all for the help with this. It seems like there is very little to go on other than people's subjective experiences. Living in Iceland, I really have no opportunity to test any lenses, as there are not even any stores that sell used large format lenses that I could try something at. I will do my best to find a reasonably priced lens or maybe two, and test it/them.

Pere Casals
25-May-2018, 15:40
You do know that the graph is half of the coverage of the lens, not the full coverage of the lens?

Of course, I know it.

The graph shows modulation_transfer vs radius, the 45 corner is at 77mm radius, as 45 diagonal is 153.7 mm, and at 77mm radius Rodenstock says the N 150 does it better than the S.


The only answer to your question is to go out and shoot with the lens, weather you have to borrow one, rent one or buy one. You are not going to understand how they perform with your scale nonsense!

Bob, I'm confident that the S is a superior glass. S vs N comes from a market segmentation, and S was the top notch. No doubt.

I know very well what is ED glass and why it was used in the S. I'm an amateur, and I have to use what I have, if I had been a Pro sure I would have been using the S range, Anyway my N 300 is crazy sharp, to me it is difficult to understand how a lens can be as good as this one is.

Ari
25-May-2018, 20:12
Thanks Ari, that is helpful info. I am pretty aware of the importance of the whole imaging chain. I use Toyo holders in 4x5, and plan on using them and Chamonix for 8x10 as well. I have a Really Right Stuff TVC-33 tripod and a BH55 head, though lately I have taken to mounting my Ebony directly on the leveling head. A heavy Ries or heavier RRS or Gitzo tripod might be called for, but I will see how I do with the TVC-33 first. It has served me well for at least seven years now with everything from 35mm to 4x5. Thanks as well for the idea regarding the Cooke. I have heard a lot of people talk about these lenses, but I have not seen anything about how they actually perform. Are they more orientated towards a smooth aesthetic, or sharpness? Given that I am mostly doing landscape work at small apertures, sharpness is more important to me than "glow" or bokeh, not that lens character is unimportant...

You're right about much of this being very subjective, but if it's clean, sharp contrast you're after, the experiences of others here is more helpful than mine.
I use the Cooke for portrait work at 311mm, and for occasional long shots. I have a 150XL for everything else.
I like the clinical sharpness of the XL, it really delivers images like a typical modern lens, in all aspects. It's unique because of its weight and size combined with a healthy image circle for 8x10, but not unique in the way it renders.

The Cooke definitely isn't a soft-focus lens by any means, it's got a very sharp rendering.
What's interesting is that great pains were taken to control flare and tame contrast, using their highly-touted coatings.
Whatever it is, there's a creamy richness to the Cooke images that is absent from any other modern lens I've used.
This may not suit the work you're doing, as the Cooke is often used wide open, or at f8; I don't think I've ever stopped it down past f11. I may have to try something at f32 or f45 one of these days.
Anyway, it sounds like a top-tier Sironar-S is what you'll need and use most; like your film holders and tripod, it's gear that once it's there, you rarely think about, because it performs as it should every time.

hiend61
4-Jun-2018, 09:18
I do not shot 8x10, only 5x7 while my stock of frozen Velvia lasts and 4x5. My Sironar N 5,6/300 is a superb lens and I would use it with confidence if I shot 8x10.

I use regularly Apo Sironar S 150/5,6 and 210/5,6. They replaced my Sironar N lenses of the same focal lenghts simply because my transparencies were a bit better with these lenses. I didnīt changed my Sironar N 5,6/300 because of the price of the Apo Sironar S 5,6/300. If I could afford it, I woud buy it.

The actual huge prices of Apo sironar S lenses of 300 and 360 mm are not worth the increase in quality from N to S.

Luis-F-S
4-Jun-2018, 18:06
Just about any 300mm plasmat should be fine. You negative sharpness will be determined by selected f-stop, focal spread and your camera support platform.

+1!! We all know that IC, but they are going to worry that they are not getting the ultimate sharpness from that over-priced lens with the marketing hype. And they buy into it. Me, I plug along with my Dagors and Artars and am very happy!

Luis-F-S
4-Jun-2018, 18:14
You do know that the graph is half of the coverage of the lens, not the full coverage of the lens?

The only answer to your question is to go out and shoot with the lens, weather you have to borrow one, rent one or buy one. You are not going to understand how they perform with your scale nonsense!

Yup, but some would much rather quote charts, numbers and senseless graphs and other nonsense than go out and take photos. I wonder if Edward Weston agonized this much about the differences between the N and the S? And he actually made images! No, he used a $5 lens that his friends thought he paid too much for it. So go ahead and spring for that Apo-Sironar Super S, so you don't have to keep worrying about it!

Luis-F-S
4-Jun-2018, 18:44
Thank you all for the help with this. It seems like there is very little to go on other than people's subjective experiences. Living in Iceland, I really have no opportunity to test any lenses, as there are not even any stores that sell used large format lenses that I could try something at. I will do my best to find a reasonably priced lens or maybe two, and test it/them.

Since you're in Reykavik, why don't you look up Gudmundur Ingolfson, who is a professional photographer and actually knows a lot! He probably has several 12" lenses as he has several 8x10 Dursts. I'm sure can explain to you the sillyness of this thread!

Bob Salomon
4-Jun-2018, 18:49
Yup, but some would much rather quote charts, numbers and senseless graphs than go out and take photos. I wonder if Edward Weston agonized this much about the differences between the N and the S? And he actually made images! No, he used a $5 lens that his friends thought he paid too much for it. So go ahead and spring for that Apo-Sironar Super S, so you don't have to keep worrying about it!

Graphs and charts are extremely important, if you know what they mean and how they can impact your choices.
But if you canít go and actually test lenses to make a decision or if budget is the single most important criteria for your choice then anything will work.
We once had a super studio as a customer that did hundreds of color catalog pages a month. They were so critical of their results that absolutely everything they used to shoot and evaluate their work was matched so each photographerís station and each art directorís work area was meticulously laid out.
For their Rodenstock lenses we had to ask the factory to match all of the lenses for color, distortion, fall off, MTF, etc.
When I visited them with their dealer we found that all of their light boxes had been measured with a color temp. Meter and the actual color balances were marked out in sharpies over the surface of each box to show the dealer how inconsistent the boxes were in color temp. Across the surface of each box!

The vast majority of members of this group are no where near as critical as that type of studio, but there are many that are and who need and make use of those graphs in their buying decision.

If you are satisfied with your $5.00 lens, fine, you arenít doing work that requires more. But if you arenít then yo7 might learn how to use those graphs!

asf
4-Jun-2018, 18:57
Silly maybe but there is a difference in the way modern plasmats render images
Any will get you an acceptable image but each will look slightly different
Whether that difference is important or not is up to the photographer

Dagors are lovely but I wouldn't shoot one for some images while for other shots nothing could be better

For modern plasmats I have preferences, in general I prefer Apo Sironar S for images without people, Symmar S for images with people
I'd take any Apo Symmar over any version of a Sironar-N, but I don't like the Apo Symmar L
I'd take any Nikkor over any Sironar-N
I don't like any Fujinon lens but I can see why others do

I don't like the way certain modern plasmats look, I like the way others do

If I had a Sironar N or a similar Fujinon and had to shoot with it (no other lens available) I would and wouldn't worry that much about it
it's a fine lens
I owned an Apo Sironar N 300 at one point, I shot with it, shot jobs with it, it was ok, nothing to complain about at all
I didn't use the 300 length often enough to shell out for Apo S

Luis-F-S
5-Jun-2018, 07:38
I own several modern plasmats all Rodenstock and a 300 Sironar N which I never use. I always use the Dagors.

Luis-F-S
5-Jun-2018, 09:29
If you are satisfied with your $5.00 lens, fine, you aren’t doing work that requires more. But if you aren’t then yo7 might learn how to use those graphs!

Bob, I didn't say I had a $5.00 lens, I said Edward Weston apparently did, and he seemed to do ok with it. I have MTF charts for lenses, well before the company you used to work for rep'd Rodenstock, and frankly I've never chosen which lens to used based on charts. I may be missing the boat, but I don't think so. L

Bob Salomon
5-Jun-2018, 10:12
Bob, I didn't say I had a $5.00 lens, I said Edward Weston apparently did, and he seemed to do ok with it. I have MTF charts for lenses, well before the company you used to work for rep'd Rodenstock, and frankly I've never chosen which lens to used based on charts. I may be missing the boat, but I don't think so. L

Of course you are missing the boat. The real test is to shoot with them. Apparently you didnít do that.
As for your having charts before I represented Rodenstock, starting in 1986, that is possible.
But you do know that I was also a rep for EPOI when they introduced the first Nikon LF lenses in the 1970s and while I repped for them as the Sinar distributor we also handled both Schneider and Rodenstock LF lenses!
And, when I left EPOI and joined HP Marketing as a rep first we sold both Rodenstock and Schneider LF lenses.
And before either of those I was with Rollei of America and, even in the early 70s Rollei was also publishing their lens curves!

So how far back do your curves go?

faberryman
5-Jun-2018, 10:19
But you do know that I was also a rep for EPOI when they introduced the first Nikon LF lenses in the 1970s and while I repped for them as the Sinar distributor we also handled both Schneider and Rodenstock LF lenses!
And, when I left EPOI and joined HP Marketing as a rep first we sold both Rodenstock and Schneider LF lenses.
And before either of those I was with Rollei of America and, even in the early 70s Rollei was also publishing their lens curves!
None of which has anything to do with lens selection, but if it makes you feel more important to reecite your career history, have at it.

Bob Salomon
5-Jun-2018, 10:22
None of which has anything to do with lens selection, but if it makes you feel more important to reecite your career history, have at it.

Read where I said the real test is to shoot with them. How could you miss that? It is the second sentence at the top of my post!
Also note, I always use my name, I don’t hide it behind a nickname! So you know who I am. Who knows who you are!

Corran
5-Jun-2018, 10:42
I wonder if all this is this helping the OP? Sheesh.

StuartR
5-Jun-2018, 10:45
Luis -- Thanks for mentioning Guūmundur. He is a friend and I had already met him about this, but I do not have the camera yet, so I have not been able to borrow a lens etc. He had recommended a 250mm f6.7 Fujinon I believe. I wound up finding a decent deal on a 1980s vintage 305mm G Claron. People seem to be of two minds about them, but it was 1/7th of the going rate of a used APO Sironar S, so I will try that first, and if I spot a good deal on a 300mm Plasmat like the Apo Sironar S or a late model from Schneider etc, I will give it a try. In the meantime I will see if the G claron meets my needs.

StuartR
5-Jun-2018, 10:47
Bryan -- It's helpful, though of course not all of it. Still, these discussions bring up a lot of good opinions and options, and I find that useful. As Bob said, the best test is to shoot them, which unfortunately is easier said than done these days, unless you want to spend over 10,000 dollars and then spend all the time reselling all the lenses that did not work. Personally, I do not!

Corran
5-Jun-2018, 11:02
Fair enough, but the squabbling and bickering about test charts and all that is what I was referring to...

Regarding your G-Claron 305mm - I have two, you'll want to check if yours is a Dagor or Plasmat design. If you Google those terms along with 305mm G-Claron you'll find a thread I started that will be helpful. It's probably a Plasmat, as the older Dagor is pretty uncommon. Both perform fine. I use the Dagor-type on my 8x20. It's sharp, but, is single-coated (as is the Plasmat) and so the usual care should be taken with regard to flare.

I shot this w/ my 305mm GC Dagor on 8x10, two sheets of it actually and stitched together:
http://www.garrisaudiovisual.com/photosharing/810-1236ss.jpg

faberryman
5-Jun-2018, 11:24
But you do know that I was also a rep for EPOI when they introduced the first Nikon LF lenses in the 1970s and while I repped for them as the Sinar distributor we also handled both Schneider and Rodenstock LF lenses!
And, when I left EPOI and joined HP Marketing as a rep first we sold both Rodenstock and Schneider LF lenses.
And before either of those I was with Rollei of America and, even in the early 70s Rollei was also publishing their lens curves!
None of which has anything to do with lens selection, but if it makes you feel more important to recite your career history, have at it.

StuartR
5-Jun-2018, 12:16
Thanks Bryan,
The serial number is over 14 million and it is in a Copal 1 black shutter (although this could be later), so I guess it is more likely to be a plasmat version. I will have a look when I get a chance to see it. Unfortunately I am not going to get a chance to start shooting until late August, so it will be awhile between updates..

Dan Fromm
5-Jun-2018, 13:34
The serial number is over 14 million and it is in a Copal 1 black shutter (although this could be later), so I guess it is more likely to be a plasmat version.

Plasmat. Dagors ended somewhat above 12 000 000.

Helcio J Tagliolatto
12-Jul-2018, 16:56
I strongly recommend you read through this thread, especially starting with my post #163 from two years ago:


http://www.largeformatphotography.info/forum/showthread.php?71322-f64&p=1321449&viewfull=1#post1321449

While I have no direct experience with the 300mm Apo Sironar S, Lenny, who I purchased my 300mm Nikkor W from, does. I do own a 135mm Apo Sironar S. With distant subjects and using f/22, it's less sharp than the 135mm Apo Sironar N and 135mm CM-Fujinon W I also have.

As always, sample variation must be considered when evaluating lenses. Good luck.

I've just read the post and the subsequent discussion. Hombre, you deserve heaven for your almost infinite patience.

Sal Santamaura
13-Jul-2018, 07:37
I've just read the post and the subsequent discussion. Hombre, you deserve heaven for your almost infinite patience.If even one reader learned to always question those who claim they know everything, it was worth the effort. :)

StuartR
13-Jul-2018, 18:16
If I have learned anything from my large format journey so far, it has been that sample variation is frustratingly more important than any other factor, at least with used modern lenses. If you find a good lens, never sell it. I am still waiting to try the lenses I bought (I can update in September), but it is really hard to get much objective information, as the results themselves seem to vary too much between lenses and people. This has not really been my experience in smaller formats, but in LF, it seems that the best way is to acquire several lenses that are generally regarded as "good" and then just test.

Pere Casals
13-Jul-2018, 20:51
If I have learned anything from my large format journey so far, it has been that sample variation is frustratingly more important than any other factor, at least with used modern lenses. If you find a good lens, never sell it. I am still waiting to try the lenses I bought (I can update in September), but it is really hard to get much objective information, as the results themselves seem to vary too much between lenses and people. This has not really been my experience in smaller formats, but in LF, it seems that the best way is to acquire several lenses that are generally regarded as "good" and then just test.

It is true that there is a sample to sample variation for the ultimate peformance, but this hapens at contrast extintion with high lp/mm, and in a region in what regular film anyway is not resolving all what a lens can deliver so while there is certain impact in ultra fine detail... that it's hard to be seen in a real photograph.

At the end we are not in a lab with flat targets, we usually photograph 3d objecs and nothing is in absolutely perfect focus, some times we need to stop the lens for DOF sake and limiting the lens performance. Modern 4x5 lenses are diffraction limited by f/22.

Rodenstock, Schneider, Fuji and Nikon were very serious manufactures and it's hard to find a lens from them that is not perfectly able, delivering tons of image quality.

The weakest link in the LF chain, IMHO, it's the photographer himself. Today we all can have gear that's way better than the one owned by AA, or Karsh. Another thing is making a comparable work...

StuartR
14-Jul-2018, 04:22
It is true that there is a sample to sample variation for the ultimate peformance, but this hapens at contrast extintion with high lp/mm, and in a region in what regular film anyway is not resolving all what a lens can deliver so while there is certain impact in ultra fine detail... that it's hard to be seen in a real photograph.

At the end we are not in a lab with flat targets, we usually photograph 3d objecs and nothing is in absolutely perfect focus, some times we need to stop the lens for DOF sake and limiting the lens performance. Modern 4x5 lenses are diffraction limited by f/22.

Rodenstock, Schneider, Fuji and Nikon were very serious manufactures and it's hard to find a lens from them that is not perfectly able, delivering tons of image quality.

The weakest link in the LF chain, IMHO, it's the photographer himself. Today we all can have gear that's way better than the one owned by AA, or Karsh. Another thing is making a comparable work...


Hi Pere,
This has not been my experience. Perhaps it is not "sample variation" so much as buying lenses that are broken. Or it could be that my workflow is more demanding. I am not trying to be arrogant or say that I am a better photographer than the greats or that these lenses could not make great images, only that I see very clear visible differences in my workflow between the lenses I have bought, and the quality of the lens IS the limiting factor with several of my lenses. I am often using flash in nature at apertures from f/11 to f/22, and I get phenomenal results from a few lenses, but from others the results have been less spectacular. This is consistent over time and throughout testing. I cannot say if it is the lens itself that is broken or suboptimal, or if it is that the "great" lenses are just better suited to my camera. But the fact remains that I can get great results with some lenses, not others. I don't think this is my failure as a photographer...I think this is the failure of the lens to perform as well as another lens. I run a lab printing exhibition prints and exhibit my own work often at large scale, so I am quite accustomed to working within fairly demanding constraints. I know when something is possibly thrown off because of wind or missed focus. I am not talking about that, I am talking about consistent results over a large sample of images indicating that one lens is performing better, and how that seems to be less tied to the maker of the lens and its model than to which lens copy it is. For example, I have had opportunity to test two APO Sironar S 150mm lenses, (well three, but one turned out to be a frankenstein lens that someone sold me with a Rodenstock front cell and Schneider rear cell), and one was clearly better than the other. I sent my copy to Rodenstock to repair, so my hope is that it comes back better, but we will see. And when I say test, I mean I produced an exhibition consisting of 12 1mX1.25m prints and 30 40x50cm prints for the National Museum of Iceland, of which I scanned and printed all the originals. So I saw a lot of samples...I then shot it alongside my own copy of the lens making test images both in the studio and in the field, and I could see variations.

Pere Casals
14-Jul-2018, 05:50
(well three, but one turned out to be a frankenstein lens that someone sold me with a Rodenstock front cell and Schneider rear cell), and one was clearly better than the other. I sent my copy to Rodenstock to repair, so my hope is that it comes back better,

With used gear a common issue is that the calibrated shims in the front cell are lost. This can be easily DIY addressed, but manufacturer's technical service, if available, is also an excellent choice, of course.

Leigh
14-Jul-2018, 06:20
With used gear a common issue is that the calibrated shims in the front cell are lost.That is quite true.
But how is a user to know whether of not that has happened?

I've serviced many hundreds of lenses/shutters.
I don't think I've found more than two or three with shims.
That seems a very small percentage.

- Leigh

Pere Casals
14-Jul-2018, 06:45
But how is a user to know whether of not that has happened?



Optimal shimming it's easy to check. I placed a microscope eyepiece (periplan, etc) in a metal plating sized like a 4x5 film holder, a 30x is perfect:

Then, with GG removed, you unscreew the front lens until you have we have best image in the center. By the number of tours and pitch we know the shimming we need. Note that we have to iterate unscreew+focus+check.

It may happen that optimal shimming for the center is not the optimal for the corner.

If we want to check that we can make some test shots of a resolution chart in we focus optimally for the center, but in each shot we screewed/unsecreewed the front cell from the optimal shimming for the center, then we judge if we may move the shimming a bit (from the optimal position for the center) in a way we get the best balance.

My guess is that we can make a shimming that's slightly better for the center or for the corners.

Instead the eyepiece, we can also place a dslr in the back, without the dslr lens, of course...

Leigh
14-Jul-2018, 07:00
Then you unscreew the front lens until you have we have best image in the center.
By the number of tours and pitch we know the shimming we need.OK.

But as soon as you loosen the front element you introduce tilt due to clearance in the threads.
That throws the front cell off-axis relative to the rear cell.
???

A proper optical test jig holds both cells rigid, and allows the spacing to be changed accurately.
Then the spacing is measured, compared with the shutter thickness, and shims calculated.

- Leigh

Pere Casals
14-Jul-2018, 07:10
OK.

But as soon as you loosen the front element you introduce tilt due to clearance in the threads.
That throws the front cell off-axis relative to the rear cell.
???

A proper optical test jig holds both cells rigid, and allows the spacing to be changed accurately.
Then the spacing is measured, compared with the shutter thickness, and shims calculated.

- Leigh

It's true that the collimation of the lenses may vary a bit if the cell is not tightened, but I guess this is irrelevant for that test, when I made those tests I moved with the hand the front cell to see the effect of that clearance, I saw no practical effect.

Anyway we can remove that clearance by making/using paper/cardboard/mylar shims.

duff photographer
14-Jul-2018, 14:13
It's true that the collimation of the lenses may vary a bit if the cell is not tightened, but I guess this is irrelevant for that test, when I made those tests I moved with the hand the front cell to see the effect of that clearance, I saw no practical effect.

Yes. I played with loosening the front element of a Fujinon (240A) and took photo's at the centre and halfway across the image circle at every full rotation of the front element (fully seated and four rotations in all). At every full rotation I refocused before taking the shots (object of focus was 25 metres away). In all five sets of images captured with a digital back (6μm pixel size) there was no discernable difference in image quality at 100% view on the computer screen.

That said I didn't check to see if there was any difference when the lens was focused closer or focused at infinity. I also didn't check for field tilt*, where the axis of tilt would be along the horizontal plane. It was a casual test just to satisfy my personal curiosity.

*EDIT 16th Jul.: Field tilt is the wrong definition to use as it correctly refers to the whole lens not the front lens group which I was discussing. My bad. Is decentring more accurate?

Pere Casals
15-Jul-2018, 09:10
Yes. I played with loosening the front element of a Fujinon (240A) and took photo's at the centre and halfway across the image circle at every full rotation of the front element (fully seated and four rotations in all). At every full rotation I refocused before taking the shots (object of focus was 25 metres away). In all five sets of images captured with a digital back (6μm pixel size) there was no discernable difference in image quality at 100% view on the computer screen.

That said I didn't check to see if there was any difference when the lens was focused closer or focused at infinity. I also didn't check for field tilt, where the axis of tilt would be along the horizontal plane. It was a casual test just to satisfy my personal curiosity.

Fujinons usually don't include shims, until I know. My guess is that the Fujinon designs make preformance not that dependant on cells spacing.

I the other hand we have have designs (like some from rodenstock) that require an accurate shimming (done in the the front cell).

Let me speculate a bit... My guess is that in some designs the cells spacing impacts in how the aberrations are corrected, so intentionally the design uses the lens spacing as a degree of freedom in the design to optimize the lens.

Dan Fromm
15-Jul-2018, 09:25
Papi, several centuries ago I noticed that Polaroid Copal shutters have somewhat longer tube lengths than jes' plain Copal shutters. Since I wanted to put some 210 mm cells of a plasmat type lens in a Polaroid Copal #1 I asked my friend Eric Beltrando (visit his site dioptrique.info) for his opinion. Eric has written a ray tracing program and used it to provide calculated curves, spot images etc. for lens prescriptions in his database.

He told me to go ahead and use the shutter. His calculations indicated that in general plasmats' image quality isn't very sensitive to small errors in cell spacing and that 0.2 mm is 0.1% of 210 mm, not enough to worry about.

If no Fujinon LF lens has shimmed cells and some Schneider and Rodenstock lenses do, there are two possible explanations. Fujinon had better quality control, or Schneider and Rodenstock were more nearly perfectionists. In all designs cell spacing affects corrections.

Pere Casals
15-Jul-2018, 15:15
In all designs cell spacing affects corrections.

OK, but in some designs it perhaps has a way greater impact.

For example a Symmar Convertible has its cells individually corrected, being a single cell usable, with the limitations a simple triplet design has.

But let's imagine that a design undercorrects Chromatic Aberration in the front cell while overcorrecting it in the rear cell. Then if we vary the cells spacing we can adjust the correction to the optimal point, as the amount of deviation added from front cell would depend on the lens spacing.

Then we can imagine that spherical aberration correction has a well lower dependence on the lens spacing, so if from the production crop we pair cells that compensate well the spherical aberration in particular then we would be able to minimize the chromatic aberration by shimming, obtaining a consistent quality production.

Just thinking in an hypothetical way to use shimming that's not related to overcoming manufacturing inconsistency, in fact the great amount of shimming that some Pro designs bear are not easy to explain from production inconsistency (IMHO).

A possibility is that (in some designs) cells spacing is an open paramenter for the manufacturing, that would allow a greater number of front/rear cells excellent combinations found.

Just speculating...

_________________

Oh, yes... I've been exploring dioptrique.info since you pointed it to me time ago. Nice info !

Dan Fromm
15-Jul-2018, 16:59
Papi, if we had eggs we could have ham and eggs if we had ham.