PDA

View Full Version : The quality and technical differences in Process lenses at 600mm and longer?



Asher Kelman
27-Jul-2011, 10:12
Process lenses are notable for generous coverage and relatively low cost for their quality.

We know the Goerz and Docter lines slightly altered the optimal 1:1 spacing of the lenses, so their variants could perform equally or better at infinity instead of 1:! for copying.

I'm interested in 1:1 work and having the maximal image circle. Detail to the edges are not so critical. So how do Wray, Nikon and Boyer lenses compare to the Red Dot Artars in these respects? I can find interesting info on the Boyer lenses but no comparisons. Do the asymmetrical Nikon Process lenses have larger angles of projection?

Dan From has kindly helped me with great links to background, but I'd also like any user experience or user examples to learn more.

Thanks,

Asher

Dan Fromm
27-Jul-2011, 11:43
Where did you get the idea that process lenses have generous coverage? And remember, the longer the lens the narrower the angle covered. This because all aberrations scale with focal length and some with angle off axis.


Detail to the edges are not so critical.

Don't be coy. How much coverage do you need? And what focal length(s) do you need? The more forthcoming you are about what you want to accomplish, the better the advice you'll get.

Remember that the last time you started this discussion you were told very consistently that your goals couldn't all be met at the same time. If your goals haven't changed, the news you get won't change either.

Asher Kelman
27-Jul-2011, 14:40
Where did you get the idea that process lenses have generous coverage? And remember, the longer the lens the narrower the angle covered. This because all aberrations scale with focal length and some with angle off axis.

.

Don't be coy. How much coverage do you need? And what focal length(s) do you need? The more forthcoming you are about what you want to accomplish, the better the advice you'll get.

Remember that the last time you started this discussion you were told very consistently that your goals couldn't all be met at the same time. If your goals haven't changed, the news you get won't change either.

Hi Dan,

I'm imaging using two 15 ft rooms separated by a wall, (which could, if need be be moved). The first lens I have bought is a 760 mm Nikkor. I chose this as a start since Learoyd used a similar focal length Germinar to image 40"x72" in his recent show at the Gallery in San Francisco. I am seriously considering a 47.5" or else 48 inch Georz or Red Dot Artar, but any special insight would be helpful. A Saphir is not currently available but a few Wray lenses are. So any experience with the Wray lens would be great, as I cannot find detailed reports in the longer focal lengths, like 48 or 68" or so. The projected image, at 1:1 magnification, will be generally be directed to Ilfochrome paper, 40" by 84", with the actual image being up to 36" by 72" or less.

The imaging standard is that of Learoyd's work, meaning that I can tolerate drop off of detail at the periphery as long as the central 2/43 of the actual image is sharp and evenly illuninated.

Have I missed anything? Let me know if there are any remaining points to define or clarify.

Thanks again for your help,

Asher

Dan Fromm
27-Jul-2011, 16:42
Ok, so your greatest film-to-subject distance is a little under 30 feet. Since at 1:1 film-to-subject distance is 4f plus a little for the internodal distance, the longest lens you can use is around 80 inches. Good luck finding something that long.

At 1:1 the 1200/12.5 Apo-Nikkor covers 175 cm, the 1780/14 covers 231 cm.

The 1200/12.5 Apo-Saphir covers 168 cm at 1:1.

The 1800/16 Apo-Ronar covers 250 cm at 1:1. The 1200ers cover 168 cm.

The dimensions you give -- 3' x 6' -- require a lens that covers 170 cm. A four foot lens -- Apo-Artars seem to be the most common -- will just do what you need.

You'll need a lens that delivers usable contrast at 8 lp/mm, might be able to shoot at apertures as small as f/128 effective, f/64 set.

Happy hunting!

Asher Kelman
27-Jul-2011, 18:50
Thanks, Dan!

Well then, there's a good response!. Any comments from you on the Apo Wrays? I've been offered a NOS 48" and a 68". But there's a 70" RDA that is in the sidelines as well.

Asher

Dan Fromm
28-Jul-2011, 05:09
Buy them, try them, and if you don't like them resell them.

I have one Apo Process Lustrar Ser. II, a 14 incher. The VM says that the Ser. IIs are the best of that line. Mine is awful, just awful, but it is filthy inside and I tried it without dismantling and cleaning.

RDAs are known quantities, but as usual with used lenses condition matters a lot.

Asher Kelman
28-Jul-2011, 09:19
Buy them, try them, and if you don't like them resell them.

I have one Apo Process Lustrar Ser. II, a 14 incher. The VM says that the Ser. IIs are the best of that line. Mine is awful, just awful, but it is filthy inside and I tried it without dismantling and cleaning.

RDAs are known quantities, but as usual with used lenses condition matters a lot.

Dan,

I read that they can get "cloudy" as they age. Is yours filthy from dirt, do you think, or could it be this aging process. Is it yellow too? I wonder if it has any rare earths that yellow and can be clarified by exposure to sunlight?

Asher

Dan Fromm
28-Jul-2011, 11:26
It looks like typical old lens schmutz, Asher. Probably sublimed lubricants, should come off. But taking the thing apart isn't easy, lotsa fiddly little setscrews have to come out before the cells can be extracted from the barrel. I have a perfectly fine 360/10 Apo Saphir so don't see the point of bothering with the Apo Lustrar.

OTOH, I have a couple of 135/4.8 Lustrars that have major crud that won't come off on the surfaces that face the diaphragm. Not sure what made it. The lenses came in SynchroCompur P shutters on Peckham Wray helicals. One of the shutters could be rescued and the helicals made two friends happy. The price, including delivery, was very right so I'm pleased with the deal.

Asher Kelman
28-Jul-2011, 12:17
It looks like typical old lens schmutz, Asher. Probably sublimed lubricants, should come off. But taking the thing apart isn't easy, lotsa fiddly little setscrews have to come out before the cells can be extracted from the barrel. I have a perfectly fine 360/10 Apo Saphir so don't see the point of bothering with the Apo Lustrar.

OTOH, I have a couple of 135/4.8 Lustrars that have major crud that won't come off on the surfaces that face the diaphragm. Not sure what made it. The lenses came in SynchroCompur P shutters on Peckham Wray helicals. One of the shutters could be rescued and the helicals made two friends happy. The price, including delivery, was very right so I'm pleased with the deal.

Dan,

I also heard that some of these lenses get "coated" from airborne vapors where darkroom chemicals are not well ventilated and this perhaps is more readily removed on the outside surfaces.

Your advice to buy and try is probably the best.

Asher

Kerry L. Thalmann
30-Jul-2011, 11:57
Ok, so your greatest film-to-subject distance is a little under 30 feet. Since at 1:1 film-to-subject distance is 4f plus a little for the internodal distance, the longest lens you can use is around 80 inches. Good luck finding something that long.

At 1:1 the 1200/12.5 Apo-Nikkor covers 175 cm, the 1780/14 covers 231 cm.

The 1200/12.5 Apo-Saphir covers 168 cm at 1:1.

The 1800/16 Apo-Ronar covers 250 cm at 1:1. The 1200ers cover 168 cm.

The dimensions you give -- 3' x 6' -- require a lens that covers 170 cm. A four foot lens -- Apo-Artars seem to be the most common -- will just do what you need.

You'll need a lens that delivers usable contrast at 8 lp/mm, might be able to shoot at apertures as small as f/128 effective, f/64 set.

Happy hunting!

Dan,

The numbers you provided seem to be based on the manufacturer's stated coverages for these lenses. At least, they closely agree with the data sheets I have for the APO Ronars, APO Nikkors and Red Dot Artars.

For example, a Rodenstock publication datet June, 1974 titled "Hints and Tables for Work with Rodenstock APO-Ronar Lenses" list the coverage angle as 40 degrees and the image circle as 175cm at f22 for the 1200mm APO Ronar for a 1:1 magnification ratio.

A Goerz brochure titled "The Lens for the Graphic Arts - Goerz Red Dot Artar" lists the coverage as 46 degrees for all focal lengths (from 4" to 70"). There is also a table that lists the film formats covered at various magnification ratios. For the longer focal lengths, the listed formats at 1:1 are:

30" (762mm) - 30"x40" (127cm format diagonal, 129cm IC at 1:1 and 46 degrees)
35" (889mm) - 36"x45" (146cm format diagonal, 151cm IC at 1:1 and 46 degrees)
42" (1067mm) - 48"x56" (187cm format diagonal, 181cm IC at 1:1 and 46 degrees)
47.5" (1207mm) - 48"x64" (203cm format diagonal, 205cm IC at 1:1 and 46 degrees)
70" (1778mm) - 72"x80" (273cm format diagonal, 302cm IC at 1:1 and 46 degrees)

The last two sets of numbers in parentheses are the calculated format diagonal and image circles at 1:1 based on the stated 46 degrees of coverage.

It is obvious from the numbers above, that any Red Dot Artar 42" or longer will cover the required 36"x72" image size at 1:1.

What is less obvious is how the shorter focal lengths will do. Keep in mind, the original application for these lenses was very demanding in terms of image quality. Most of these process lenses throw larger image circles than their stated coverage angles. In other words, they don't employ field stops, or other means of mechanical vignetting to limit their coverage to the stated angle (40 degrees, 46 degrees, etc.). So, the image quality degrades beyond the stated coverage, but there is still image there.

The question then becomes what level of image quality is necessary for the OP's application? He's imaging directly on paper, and not on high contrast lithography film. He also stated that he doesn't mind degraded image quality beyond the central 2/3 of the image area. With that in mind, I suspect a 35" Red Dot Artar will probably meet his needs. As may some of the 30"/750mm lenses, like the 30" Red Dot Artar and 750mm APO Germinar.

Since this is subjective, as you recommended, testing the individual lenses is really the only way to determine if anything shorter than a 42" Red Dot Artar will meet the OP's requirements and desired level of image quality for his unique application.

Kerry

Asher Kelman
30-Jul-2011, 12:21
Dan,

The numbers you provided seem to be based on the manufacturer's stated coverages for these lenses. At least, they closely agree with the data sheets I have for the APO Ronars, APO Nikkors and Red Dot Artars.

I really appreciate the time Dan, you and others have taken to help set me on the right path. I have now one copy of a 760 mm Nikkor and a 471/2 inch Red Dot Artar, Scneider label. I will be getting alternates and sell what I don't need.



A Goerz brochure titled "The Lens for the Graphic Arts - Goerz Red Dot Artar" lists the coverage as 46 degrees for all focal lengths (from 4" to 70"). There is also a table that lists the film formats covered at various magnification ratios. For the longer focal lengths, the listed formats at 1:1 are:

30" (762mm) - 30"x40" (127cm format diagonal, 129cm IC at 1:1 and 46 degrees)
35" (889mm) - 36"x45" (146cm format diagonal, 151cm IC at 1:1 and 46 degrees)
42" (1067mm) - 48"x56" (187cm format diagonal, 181cm IC at 1:1 and 46 degrees)
47.5" (1207mm) - 48"x64" (203cm format diagonal, 205cm IC at 1:1 and 46 degrees)
70" (1778mm) - 72"x80" (273cm format diagonal, 302cm IC at 1:1 and 46 degrees)

The last two sets of numbers in parentheses are the calculated format diagonal and image circles at 1:1 based on the stated 46 degrees of coverage.

Since Goerz apparently adjust the lens spacing either side of the aperture to optimize more for shooting at infinity than 1:1, although the performance are still stellar everywhere, could it be that these adjustments affect the image circle and circle of illumination, or is this going to be trivial?



It is obvious from the numbers above, that any Red Dot Artar 42" or longer will cover the required 36"x72" image size at 1:1.

We know form Learoyds work at 1:1 with the Apo Germinar at 750 mm, thesystem covers the paper, albeit with degraded corners which we recognize but most folks expect for a classic portrait, where we'd want, (and put in), vignetting, anyway.


Asher

Dan Fromm
30-Jul-2011, 13:43
Kerry, what the OP wants to do needs around 8 lp/mm with usable contrast for much, not all, of the frame. How much depends on how he positions his subject.

There are at least two coverage concepts used on this forum. The generous one -- circle illuminated, and never mind about resolution or contrast off-axis -- is too vague to be safe to use. The more stringent one -- how far off-axis is the image usable? -- is used by at least Rodenstock and Schneider. I haven't found MTF curves, which address the question directly, for Schneider process lenses but Rodenstock published MTF curves for Apo-Ronars in their Process Lens Handbook.

Apo Ronar MTF curves, as published in the Process Lens Manual are surprising. As far as I know all Apo Ronars have the same prescription, but some focal lengths have nil contrast at 8 lp/mm, and with bad astigmatism; others have as much as 60% contrast at the edge of coverage with nil astigmatism. I"m not sure there's a pattern. This is very disturbing since it isn't consistent with what I think I know.

Some time ago Eric and I had a polite disagreement about Apo Saphirs. I found mine sharpest centrally at f/16, he insisted they as good wide open. He rechecked his calculations, concluded that I was right. Further on that point, his calculations show that they're essentially aberration free to around 15 degrees off axis; Boyer claims they cover around 48 degrees (less for the longer ones). Boyer are optimists, Eric may be too demanding, Schneider and Rodenstock seem to be realists.

We agree that the only way for the OP to find lenses that will meet his needs is to buy and try. One reason is a lack of clarity about what he needs and what published coverage figures (from users and from the manufacturers) mean. The other, which hasn't been discussed much, is variability in beat-up old lenses' quality. Some are in good order and perform as they did when new; others, e.g., that Wray I mentioned in this thread, aren't.

A 42 incher might do for the OP. A 750 Germinar does for Learoyd, who doesn't seem to frame tightly. But the OP would probably be safer with a 48 incher, and fortunately he has the space to use one.

Cheers,

Dan

Asher Kelman
30-Jul-2011, 23:26
Kerry, what the OP wants to do needs around 8 lp/mm with usable contrast for much, not all, of the frame. How much depends on how he positions his subject.

There are at least two coverage concepts used on this forum. The generous one -- circle illuminated, and never mind about resolution or contrast off-axis -- is too vague to be safe to use. The more stringent one -- how far off-axis is the image usable? -- is used by at least Rodenstock and Schneider. I haven't found MTF curves, which address the question directly, for Schneider process lenses but Rodenstock published MTF curves for Apo-Ronars in their Process Lens Handbook.



Thanks Dan (and once again Kerry in PMs), for your insight and generous help.

I'm strongly considering adding to a 760mm Apo Germinar to compare to the 760mm Nikkor. The later appears to be an asymmetrical design and might be different than the 760 Germinar which we know gives just adequate coverage in the reference work of Learoyd. We must look to do at least as good, but not worse! So the 760 Apo Germinar sounds necessary to test.

I'd test the Apo Saphirs if I found them! Someone here seems to be looking for me, LOL. When I ask, they say, we just had a call for the same lenses!

Obviously I'm not going to be scanning giant sheets of film to characterize the lenses, but I might put 4x5 film over key areas in the image circle on a vacuum board. I am getting more lenses than I will use as I'm sure that in practical use, there will be surprises and I am not prepared to invest a year with testing one lens after the other. Instead, I'll do everything in one go and get it over and done with!

Asher

Dan Fromm
31-Jul-2011, 06:57
Asher, according to my Apo Nikkor catalogs the 760 is a dialyte type. Symmetrical. There should be four strong and no weak reflections from each cell. If it is a tessar type there will be two strong and one weak reflection from the rear cell; the weak reflection may be hard to see.

Long Apo Saphirs are very uncommon. If you're up for paying 1982 list price (750, $2500; 800, $2800; 900, $4900; 1200, $8700) Rolyn Optics might have some new old stock lenses.

Kerry L. Thalmann
31-Jul-2011, 11:27
Kerry, what the OP wants to do needs around 8 lp/mm with usable contrast for much, not all, of the frame. How much depends on how he positions his subject.

Is the paper he's using to capture these images even capable of 8 lp/mm? I have no idea, so I'm asking. In general, the resolving capabilities of paper are much less than film. That is one of the reasons why I mentioned that his application is less demanding than the original application these lenses were designed for, and could, therefore, possibly push the coverage beyond the manufacturer's published specs. Of course, he has also stated he only needs maximum performance over the central 2/3 of the image area, which further relaxes the performance required for his application. Furthermore, such huge prints will have a much greater viewing distance than more modestly sized prints (or lith film designed for photographic reproduction), which reduces the required performance of the lens used to capture the image even further.


A 42 incher might do for the OP. A 750 Germinar does for Learoyd, who doesn't seem to frame tightly. But the OP would probably be safer with a 48 incher, and fortunately he has the space to use one.

The manufacturer's specs for the 42" Red Dot Artar list the coverage as 46 degrees with an image circle in excess of 180cm at 1:1. This is significantly more than the 168cm required by the OP for his application. Given the original intended application for this lens, one would hope the manufacturer's original specs were rather stringent and the performance criteria required higher for the intended application greater than those of the OP. So, why wouldn't a 42" Red Dot Artar meet the OP's needs (assuming it's in good condition and not suffering from damage or defects)?

Kerry

Kerry L. Thalmann
31-Jul-2011, 11:29
I'm strongly considering adding to a 760mm Apo Germinar to compare to the 760mm Nikkor. The later appears to be an asymmetrical design and might be different than the 760 Germinar which we know gives just adequate coverage in the reference work of Learoyd. We must look to do at least as good, but not worse! So the 760 Apo Germinar sounds necessary to test.

The basic design of these two lenses is different. As Dan stated, the 760mm f11 APO Nikkor is a 4/4 dialyte. I have both the manufacturer's brochure and one of these lenses. So, I can confirm that it is indeed a 4/4 dialyte. The manufacturer lists the coverage as 42 degrees for an image circle of 117cm at 1:1.

The 750mm f9 APO Germinar is not a 4/4 dialyte. The construction of this lens is a 6/6 symmetrical design. Again, I have both the manufacturer's brochure and a lens in my possession and can confirm this is correct. The manufacturer lists the coverage as 46 degrees at 1:1 for an image circle of 127cm.

It is interesting that Docter also published larger angles of coverage for these lenses for use at infinity (51 degrees at f9 and 56 degrees at f14.5) and that the coverage increased substantially when stopping down. You can read more about these specs in Arne Croell's excellent article on the Docter lenses. Note: this is a newer version of Arne's article and includes additional information not found in the article on the static pages of this site.

In any case, according to the manufacturer's specs on both lenses, the 6/6 APO Germinar should cover more than the 4/4 APO Nikkor. The 6/6 APO Germinar also seems to have more potential for extended coverage if the criteria of acceptable performance is relaxed.

But, once again, the only way to know for sure is to test both lenses side-by-side and determine which best suits your needs. At least in the case of the 750mm APO Germinar, you also have Learoyd's work as a reference to how this lens performs for this application.

Kerry

Asher Kelman
31-Jul-2011, 12:12
The basic design of these two lenses is different. As Dan stated, the 760mm f11 APO Nikkor is a 4/4 dialyte. I have both the manufacturer's brochure and one of these lenses. So, I can confirm that it is indeed a 4/4 dialyte. The manufacturer lists the coverage as 42 degrees for an image circle of 117cm at 1:1.


Kerry,

There sure is some muddle about this in the WWW!


(Jan 23, 2003; 04:09 p.m., photo.net)
Re: The debate about the symmetrical vs non-symmetrical designs of APO-Nikkors: There were two types made: Symmetrical (all f/9)240, 360,420,480,610 and(f/11)720; Asymmetric (all f/9)150,210,300,450,600,750,900,1200 and (f/14)1800. Modern (multicoated) versions were all symmetrical and all the symmetric ones had 4 elements in 4 groups. The asymmetric lenses 4 elements in 3 groups. Symmetric ones were based on artar & the asymmetric -tessar. All were optimised for 1:1 reproduction only. Angle of coverage goes from 35 degs to 46. Process Nikkors and W.A.Apo nikkors have >70 degs of coverage (info -from original Nikon literatures).

Source (http://photo.net/large-format-photography-forum/004O81?start=10).

Well, my lens is a 760mm f11, so that does not fit into the symmetrical list which has a 720 mm f11 and neither does it match the asymmetrical 750mm f 9.0. I don't know where Vivek got his information. but clearly, it's not the entire story.

Asher

Kerry L. Thalmann
31-Jul-2011, 12:28
Kerry,

There sure is some muddle about this in the WWW!



Well, my lens is a 760mm f11, so that does not fit into the symmetrical list which has a 720 mm f11 and neither does it match the asymmetrical 750mm f 9.0. I don't know where Vivek got his information. but clearly, it's not the entire story.

Asher

Asher,

The 750mm f9 is a 4/3 APO Tessar type with less coverage (~35 degrees). The 760mm f11 is a 4/4 dialyte with 42 degrees of coverage. That's what mine is and what's listed in the Nikon brochure I have.

The list above is also incomplete. There were also 4/4 dialyte APO Nikkors in the 890mm f11 and 1210mm f12.5 focal lengths.

Kerry

Dan Fromm
31-Jul-2011, 12:49
Asher, I'm mortally offended that you don't believe me, the more so since I gave sources.

I have the catalog that Vivek Iyer quoted. It lists, among others, a 750/9 tessar type Apo-Nikkor. A newer catalog lists, among others, a 760/11 dialyte type Apo-Nikkor. Have your vision checked, you misread 750 for 760.

Kerry, I have a piece on Apo- and Process-Nikkors pending on the French LF site. I thought I gave Asher a pre-publication copy. It includes the lenses you listed. If you want a prepublication copy -- I think you have all of the catalogs that I do -- send me a PM with your e-mail address.

Asher Kelman
31-Jul-2011, 15:59
Asher, I'm mortally offended that you don't believe me, the more so since I gave sources.

Dont be offended, Dan, LOL, no mortal wound intended!!!!

I just couldn't locate the 760 f11 lens in the lists I have looked at, just the 720 f11 Vivek writes about. Maybe that's the mistake! Is there in existence a 72 f11 Apo Nikkor? Anyway, As Kerry points out, some sources so appear somewhat incomplete, so your new article is most welcome.


I have the catalog that Vivek Iyer quoted. It lists, among others, a 750/9 tessar type Apo-Nikkor. A newer catalog lists, among others, a 760/11 dialyte type Apo-Nikkor. Have your vision checked, you misread 750 for 760. I totally believe you! Thanks!


Kerry, I have a piece on Apo- and Process-Nikkors pending on the French LF site. I thought I gave Asher a pre-publication copy.

I need to refresh my memory on that one. Could you send it to me at editor.opfATmac.com

Dan, this again pushes me to get the 750 Apo Germinar as well. :) The image circle should be greater too than my 760 f 11 Nikkor.

Asher

Dan Fromm
31-Jul-2011, 16:15
sent

Asher Kelman
31-Jul-2011, 22:18
Thanks, Dan! Much appreciated!

Joerg Krusche
1-Aug-2011, 02:37
Asher,

a horizontal repro camera .. is that the way you plan to go ?

joerg

rdenney
1-Aug-2011, 07:58
Is the paper he's using to capture these images even capable of 8 lp/mm? I have no idea, so I'm asking.

Asher said he was using Ilfochrome. I found a reference in the archives where Emmanuel Bigler was quoting an Ilford publication (no longer available at the link he supplied) stating that Ilfochrome was capable of far higher resolution than 8 lp/mm (more like 63). I'm not sure I believe that, but I'm pretty comfortable that it will outresolve good eyes.

And that's where the 8 came from, I suspect. I think Dan was saying that the prints should be as sharp as the viewer's vision when viewed up close, given that the photograph will be projected 1:1 in the camera.

Rick "putting the pieces together" Denney

Dan Fromm
1-Aug-2011, 08:33
I think Dan was saying that the prints should be as sharp as the viewer's vision when viewed up close, given that the photograph will be projected 1:1 in the camera.

Rick "putting the pieces together" Denney

Exactly

Asher Kelman
1-Aug-2011, 09:34
Asher,

a horizontal repro camera .. is that the way you plan to go ?

joerg

As Dan says, yes!

Two rooms separated by a wall with a square hole for a recessed bellows extending back into the camera room. The lens will be on a board so it will be exchangeable and perhaps there will be some simple ability to raise and lower the frame in the wall and with a little swing too. Just wood sliding on wood, nothing fancy. I'm concerned about narrow DOF!

So any insight to these lenses as to slight benefits in DOF. Seems they would all behave the same.

Asher

Dan Fromm
1-Aug-2011, 09:36
So any insight to these lenses as to slight benefits in DOF. Seems they would all behave the same.

AsherThe law is the law. If you want infinite (they say) DoF, use a pinhole. To my eye, fuzzy everywhere isn't good but tastes differ.

Joerg Krusche
1-Aug-2011, 09:39
right,

in that range lenses are lenses .and for your planned application more or less exchangeable,

best,

joerg

Asher Kelman
1-Aug-2011, 10:16
The law is the law. If you want infinite (they say) DoF, use a pinhole. To my eye, fuzzy everywhere isn't good but tastes differ.



Dan,

For sure pinhole would be far less expensive, LOL and I did think of that! However, there are only three approaches to lighting: having subjects stay still for as long as it takes (even in the brightest light they can tolerate), using massive flash or some combination.

Except for for still life, a blindfolded nude, (or a blind folded-nude for that matter), the limited tolerated to high intensity continuous room light is a barrier to work where 3 ISO medium is used in the camera!

I do know that 32,000 W.S. at f22 works. That covers losses from the filtration to get rid of UV and get the color temp right. And of course, that 32,000 Joules is just the figure of the nominal settings. If one changes the MFR it could be much different.

So as one increases DOF by stopping down, each time one would double the power of the strobe needed!

Asher

Farid
1-Aug-2019, 08:14
.

At 1:1 the 1200/12.5 Apo-Nikkor covers 175 cm



Hi Dan,

as i am not even a starter in wet plate photography, but collecting all information i can. i have some open questions. My Idea is to get portraits. torso upwards, but also landscapes maybe with people standing in it. my Idea is to get a Nikkorr 1210mm f12.5 . using this in combination with a light proof tent as first idea to be flexible...maybe later my VW bus T3 ;)

- So my main question is. if I under stand right the distance of a 1200mm Nikon lens to the wet plate would be 175cm displaying a 1:1 ratio ...

- Is there a chance to get a projection of a max size of 1x1m

- what if I want the person to step closer... i need to move the plate to adjust the sharpness etc...

can also use this kinda huge setup to make a 30x40cm image?

and is it worth to buy specific this nikon lens. (quality wise and price wise 2300$ )

maybe important to know i plan mostly to shoot in sunlight. but i also own 3 Profoto gen. with 3 1200W lights


thanks for helping me out with my very first and most important peace of gear :)

smiles from switzerland

farid

Pere Casals
1-Aug-2019, 08:55
relatively low cost.

I got my mint LOMO O-2 600mm (4/4 Dialyte) for some $30, now they are more expensive, perhaps $150 can be offered.

Lens lp/mm ratings in russian catalogs were very low, but I guess that testing conditions were quite different (%MTF) in the soviet times. I was not expecting much, but I've been inspecting several 8x10 shots and the lens it's very sharp, I'm curious about performance, and I plan to check it well. If no enlargement it's planned for sure it has way more IQ than required for total graphic quality.

it has a primitive coating, but's coated.


https://www.arnecroell.com/eastern-block-new.pdf

Dan Fromm
1-Aug-2019, 09:17
Farid, you're trying to be another Richard Learoyd. Google him. You might even try to find him. I don't do anything remotely like what he does so am not a very good person to ask about what he does, how he does it, and how he solved problems.

Learoyd uses, according to my friend Eric Beltrando, a 760 mm Apo-Ronar. He started with a 1200 Apo-Saphir, found it too long.

You should learn close-up photography arithmetic before you spend a penny on anything but that and before you dream more. You're a new arrival here, may not be aware of all of this site's resources. Look in the FAQs for information about lenses and about close-up work. There's another resource, a list of links to lens catalogs and so on, that you should also consult. A link to it is in the first post of this https://www.largeformatphotography.info/forum/showthread.php?138978-Where-to-look-for-information-on-LF-(mainly)-lenses discussion. In particular, see its discussion of books on closeup photography. If I were you I'd buy a copy of Lefkowitz and study it.

I've never understood how people who use tent cameras maintain lens-film plane alignment. To me that problem seems quite difficult.

You're new here, we know very little about you and your experience/skills. Please tell us more, it will make communicating with you easier.

Good luck, have fun,

Dan

Dan Fromm
1-Aug-2019, 09:18
I got my mint LOMO O-2 600mm (4/4 Dialyte) for some $30, now they are more expensive, perhaps $150 can be offered.

Lens lp/mm ratings in russian catalogs were very low, but I guess that testing conditions were quite different (%MTF) in the soviet times. I was not expecting much, but I've been inspecting several 8x10 shots and the lens it's very sharp, I'm curious about performance, and I plan to check it well. If no enlargement it's planned for sure it has way more IQ than required for total graphic quality.

it has a primitive coating, but's coated.


https://www.arnecroell.com/eastern-block-new.pdf

Papi, in the USSR resolution was usually measured at full aperture.

Pere Casals
1-Aug-2019, 09:36
Papi, in the USSR resolution was usually measured at full aperture.

Thanks Dan, it's always a pleasure to learn something from you.

The LOMO 600 (@ f/22) shaped very well a cigarette butt from 170m far, so I guess that at least 40Lp/mm had to be there. I'll check it.

Farid
2-Aug-2019, 01:13
I've never understood how people who use tent cameras maintain lens-film plane alignment. To me that problem seems quite difficult.


i would maybe do it with a laser measuring device... or similar but i know what you mean...



Hi Dan,

thanks for your response.




You're new here, we know very little about you and your experience/skills. Please tell us more, it will make communicating with you easier.



this is stuff i do most of them taken with the D3s Nikon and Leica M9


www.faridlaid.com


but i also have the PB-6 Bellow mount from nikon...usually combines with the macro 105 f 2.8 nikkorr lens ... but i also used the 20mm retro mouned .. not much into macro though at the moment.

I own 3x 1200 Profoto generators and 3 1200W Lights ... so enough light to get something out of it i hope :)


I just have no clue about the ratios soon as i take a lens at a sertain distance from the body

smiles
farid

jon.oman
2-Aug-2019, 07:04
farid, Impressive images on you web site!

Farid
5-Aug-2019, 15:27
thanks a lot Jon, glad you like it :)

best regards
farid

erian
6-Aug-2019, 17:35
I think what might be interesting for you is work of Brendan Barry https://brendanbarry.co.uk/category/work/