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1erCru
28-Feb-2017, 11:46
I've only taken and developed around 10 shots on my first LF camera. Using a Sinar P and the results are pleasing for the most part. The resolution for reasonably large prints is certainly there. I can see how people who can afford drum scans can print huge using this format. I was even happy with the HP5 Plus shots when scanned on an Epson.

I've been researching the sharpest aperture of this lens. Schneider says it's around f11. A lot of people say it resides around f16 - f22. I shoot mainly still life, arranged objects and sculpture. Almost all of the shots I've taken have been f8-f11. I took one @ 5.6 and the results were soft. I guess I need to start taking meticulous notes.

I've been reading about diffraction causing softness. I assume this effect would not occur at f16 but what about f22? I'm fully aware I need to shoot a lot more and discover this for myself and was looking for a bit more validation on the subject. Thanks for any info.

Tobias Key
28-Feb-2017, 11:53
I have this lens. I am a portrait shooter and I prefer it to use at f16-22, but that is as much down to the practicalities of shooting living subjects as anything else. I've never really noticed any fall off in sharpness in F22, I just pick the f-stop I feel I need to get the shot I want and to have some reasonable leeway in focusing. I'd rate it as the best lens I have ever used, across all formats, it really is out of this world.

Bob Salomon
28-Feb-2017, 11:55
Your lens is diffraction limited at F22 for 45. Beyond that you are in diffraction.

Kevin Crisp
28-Feb-2017, 14:31
Diffraction is certainly a fact of physics, but something people hear about and then get unduly concerned about. Film and paper size matter. Unless you are printing HUGE prints (something beyond 20x24 off a 4X5 negative) then you aren't going to notice degradation from f:22 or f:32. F:45? You will notice a very slight difference, in close inspection, in a 16X20 print. And you will not be looking at it from a normal viewing distance to see the difference and you might need a magnifying glass. I can differentiate my few f:45 negatives, but only with a loupe, which isn't a very realistic standard.

F:5.6 is not the Symmar's best aperture, to be sure. But absent some extraordinary demands it is should be plenty sharp in practical terms from f:8 to f:32. If you look at the index to one of John Sexton's books with technical details, look at the taking apertures....f:22 to f:45. Or consider the f:64 Group.

EdSawyer
1-Mar-2017, 07:17
Based on these tests, looks like f/11 is max sharpness: http://www.hevanet.com/cperez/testing.html

Luis-F-S
1-Mar-2017, 08:22
I use modern lenses at f/22 Dagors at f/45. Wide-open is for focusing not for shooting!!! Soft focus or special purpose lenses are a different story .

Bob Salomon
1-Mar-2017, 08:37
Based on these tests, looks like f/11 is max sharpness: http://www.hevanet.com/cperez/testing.html

Except this test is meaningless, it is not repeatable, it is loaded with variables:
Lighting, exposure, developer strength, developing time, atmospheric conditions, alignment to the chart, strength of loupe, quality of the loupe, condition of the viewing eye, etc.. at best, all that this test shows is the performance of a particular lens. Additionally, since the tests are not scientifically controlled and are done at different times, by different testers on used lenses, most from other owners you can't even know if the lenses were within new factory specification when the tests were done.
If you can find them look at MTF, that is how lens and camera manufactures have been testing lenses for decades, distortion curves, color curves, fall off curves, and then you will see where a lens performs best.

Luis-F-S
1-Mar-2017, 10:09
So you've taken 10 shots and you're concerned about the sweet spot. Suggest you put that off and take more pictures. I've probably made 5,000 4x5 frames and never worried about any spots unless they were on the negative.

Martin Aislabie
1-Mar-2017, 10:14
So you've taken 10 shots and you're concerned about the sweet spot. Suggest you put that off and take more pictures. I've probably made 5,000 4x5 frames and never worried about any spots unless they were on the negative.

+1

Martin

Richard Wasserman
1-Mar-2017, 10:24
So you've taken 10 shots and you're concerned about the sweet spot. Suggest you put that off and take more pictures. I've probably made 5,000 4x5 frames and never worried about any spots unless they were on the negative.

I concur. I think the whole issue of diffraction is overblown. My feeling is if you need to stop down to make the photograph, you stop the lens down to whatever it needs to be and don't worry about it. It's better to have a possibly technically imperfect image than none at all. In my experience with modern lenses the differences are quite subtle. I have made 40x50 inch prints and when seen from a reasonable viewing difference, maybe the large format photographers in the audience can see that I shot at f/32 (or even f/45 on occasion), but no one else cares. I try to shoot at f/16-22, but if I can't, so be it.

Bob Salomon
1-Mar-2017, 10:36
I concur. I think the whole issue of diffraction is overblown. My feeling is if you need to stop down to make the photograph, you stop the lens down to whatever it needs to be and don't worry about it. It's better to have a possibly technically imperfect image than none at all. In my experience with modern lenses the differences are quite subtle. I have made 40x50 inch prints and when seen from a reasonable viewing difference, maybe the large format photographers in the audience can see that I shot at f/32 (or even f/45 on occasion), but no one else cares. I try to shoot at f/16-22, but if I can't, so be it.

Of course we all presume that one is focusing at the correct distance to maximize the depth of field available at F22 before resorting to stopping down further into diffraction territory.

Richard Wasserman
1-Mar-2017, 11:05
Of course we all presume that one is focusing at the correct distance to maximize the depth of field available at F22 before resorting to stopping down further into diffraction territory.

Of course. Although it does seem to be an area where many newcomers to LF struggle.

ic-racer
1-Mar-2017, 11:57
If you are taking pictures of three-dimensional objects (as opposed to flat-field) then you ideal aperture is found with this equation (ignore this if you are doing flat-field copywork):

D(mm) F
1 16.6
2 22.6
3 32.2
4 32.6
5 32.9
6 45.2
7 45.4
8 45.6
9 45.8
10 64

(Table copied from the LF home page)

Bob Salomon
1-Mar-2017, 11:57
Of course. Although it does seem to be an area where many newcomers to LF struggle.

Being a new comer to LF isn't the problem. You should also have learned the proper point to focus on for any other format to maximize sharpness through the depth of field zone. That is basic photography.

Richard Wasserman
1-Mar-2017, 12:04
Being a new comer to LF isn't the problem. You should also have learned the proper point to focus on for any other format to maximize sharpness through the depth of field zone. That is basic photography.

Unless you come from the world of auto-focus cameras. Which I think a lot of people do. And is why I don't care for auto-focus cameras much of the time. Although they do have their attractions....

Luis-F-S
1-Mar-2017, 12:19
I concur. I think the whole issue of diffraction is overblown. My feeling is if you need to stop down to make the photograph, you stop the lens down to whatever it needs to be and don't worry about it. It's better to have a possibly technically imperfect image than none at all. In my experience with modern lenses the differences are quite subtle.....

Try telling a client that the general DOF is just not there, but the areas in focus are incredibly sharp because you used the lens at it's optimum aperture. You wouldn't stay in business very long!


Being a new comer to LF isn't the problem. You should also have learned the proper point to focus on for any other format to maximize sharpness through the depth of field zone. That is basic photography.

Bob, you mean we have to know basic photography to use LF? I think we need a programmable LF camera!

Bob Salomon
1-Mar-2017, 12:34
Try telling a client that the general DOF is just not there, but the areas in focus are incredibly sharp because you used the lens at it's optimum aperture. You wouldn't stay in business very long!



Bob, you mean we have to know basic photography to use LF? I think we need a programmable LF camera!

Sinar made one, but no one bought it.
There was also a company that tried to make a modular, computerized view camera system with backs from 69 to 1114. They showed prototypes and design drawings at two consecutive Photokinas but it never got enough interest to go anywhere. The former Export Manager from Linhof was hired to show and promote it.
The money behind it came from a Norwegian who owned salmon farms and he sent in slabs of smoked salmon the first year for visitors. Great salmon but it still didn't get enough interest to get the thing produced.
Somewhere I still have the brochure and life size drawings.

Armin Seeholzer
1-Mar-2017, 12:42
Yes Bob the Sinar e was the beginning of the end of Sinar. The Koch family where clever to sell it short after this disaster!

Pere Casals
1-Mar-2017, 13:23
I've only taken and developed around 10 shots on my first LF camera. Using a Sinar P and the results are pleasing for the most part. The resolution for reasonably large prints is certainly there. I can see how people who can afford drum scans can print huge using this format. I was even happy with the HP5 Plus shots when scanned on an Epson.

I've been researching the sharpest aperture of this lens. Schneider says it's around f11. A lot of people say it resides around f16 - f22. I shoot mainly still life, arranged objects and sculpture. Almost all of the shots I've taken have been f8-f11. I took one @ 5.6 and the results were soft. I guess I need to start taking meticulous notes.

I've been reading about diffraction causing softness. I assume this effect would not occur at f16 but what about f22? I'm fully aware I need to shoot a lot more and discover this for myself and was looking for a bit more validation on the subject. Thanks for any info.



When I started with LF I also was investigating a lot about Sweet Spots of lenses.

I concluded that 4x5 can deliver much more image quality than one can use and this do not depends of lens performance at /8 or /16. As Bob Salomon says, beyond f/22 difraction starts damaging image quality (in pure resolving power terms), but still a shot at /32 can be better than one at /11 because DOF.

I advice you (once in the life...) to technically test your glass gear, just to know when things are important or not, and to have clear ideas.

Just place a DSLR in the back of your camera and use rise and shift to explore the image circle at different apertures, if you can take the shots with a powerful (1/30000s) flash to remove vibrations of the measurement. You'll see that the aperture you use is important when you explore the boundary of your image circle, but probably you'll get more than needed image quality in the center at /5.6 or /22.

A suitable/cheap DSLR for this job is a Nikon D3300, it has 24 Mpix in a tiny sensor (high pixel density), and it don't has the optical low pass filter as D3200 model. You can simply print the resolution target, you are not to make scientific test, just you are to compare practical situations. But you have to understand the basic concepts to compare: if you want to compare different focals, this means that the projection size of the resolution target on the ground glass has to be the same in case focal is different, so to compare a 150mm lens to a 300mm the target has to be placed at double distance or target size has to be the half.

Just place a "resolution target" chart (USAF 1951 or the like) and compare. See it with your eyes. So learn how a USAF 1951 target image is interpreted.

Using a DSLR is simple and convenient and it do not accounts for other factors as film own resolution limits.


Other problems that can end in soft images:


1) Check film plane vs Groung Glass matching. A common problem is a back that in the past had a fresnel installed in the inner side of the GG and back was corrected for that. If the fresnel was in the outer side no correction was needed.

So take a shot of a rule placed on the ground, and remember the number of the rule that was in focus in the GG, later same number should be in focus in the negative.

This can be related to having soft images wide open, when stopping down DOF on film is larger.


2) Vibrations !!!! What kind of tripod do you use??? Just fix a toy laser pointer in the front standard and make it point to a wall some 10m far and see how the laser point on the wall vibrates a few seconds until it stops (or not in case of wind).


3) Elastic tripod? no problem, if tripod head bends while inserting the holder but returns to the original position it is OK, but if you used movements and the camera doesn't return to the original place then the (tilted) plane of focus goes far from it was when it was observed in the GG.


4) Scanner ?? do you use "area scan" on the glass??? be careful with this, you have to use the 4x5 holder of the V750 (700, 800, 850). Inspect negative (sharp in focus edges of fine detail) with a 20X magnifier and compare. Some area scan modes will deliver very soft images.




In practical terms a 4x5 shot with a common 30 years old lens (say Sironar-N or Symmar-S) and a sharp film (Kodak TMX or Adox CMS 20) it has to deliver an image quality worth of 150 to 250 preceptual megapixels, speaking in DXO people terms.

You may know that a D810 may deliver some 24Mpix (perceptual) with a $2800 professional 70-200 2.8 excellent zoom, or a bit more (30 Mp?) with a $5500 300mm G ED

So with 4x5 you have to obtain damn sharp images even at /5.6 !!!! If you don't then an unknown problem is there !

Corran
1-Mar-2017, 20:09
Please contact DXO and ask them to test a 4x5 camera w/ T-Max 100 and a Symmar-S of some variety and see how many "perceptual megapixels" they come up with. I can guarantee you it's not 150+.

1erCru
1-Mar-2017, 23:21
Thanks for this response it was helpful.

I'm using a heavy and sturdy manfrotto with no head. Elastic tripod doesn't seem to be the issue.

Vibrations , laser pointer.. great idea!

As far as the ground glass. I'll look into this.

I scan with an 850 and Epson 4x5 included holder. I use Silverfast AI studio for color and Epson Scan for b/w. The sharpness increased a lot from 5.6 to 8. I've taken the same shot at f11-f22. Will develop.

1erCru
2-Mar-2017, 19:18
I'm just going to shoot @ 5.6. Seems like the pursuit of sharpness is a dangerous one.

Kevin Crisp
2-Mar-2017, 19:22
Well then you might consider that shutters are typically off at higher speeds.

Luis-F-S
2-Mar-2017, 19:54
I'm just going to shoot @ 5.6. Seems like the pursuit of sharpness is a dangerous one.

Did you NOT LEARN ANYTHING? 5.6 is for FOCUSING NOT SHOOTING! ARGGGGG!!!!!!!!!!!

Kirk Gittings
2-Mar-2017, 19:57
So you've taken 10 shots and you're concerned about the sweet spot. Suggest you put that off and take more pictures. I've probably made 5,000 4x5 frames and never worried about any spots unless they were on the negative.

+2

1erCru
2-Mar-2017, 22:00
Didn't think I need an emoticon for sarcasm on that one.

Oren Grad
3-Mar-2017, 08:58
The digital-vs-film debate that broke out here has been moved to its own thread:

http://www.largeformatphotography.info/forum/showthread.php?137602-Another-digital-vs-film-debate

Luis-F-S
3-Mar-2017, 09:39
Thank you, this was getting rather tiresome and off course!

Pere Casals
3-Mar-2017, 10:23
The digital-vs-film debate that broke out here has been moved to its own thread:

http://www.largeformatphotography.info/forum/showthread.php?137602-Another-digital-vs-film-debate

Thanks, a very good idea !

Right decision, and Just in Time.

Tobias Key
3-Mar-2017, 11:28
Another good tip is to get a stable, tall stool to sit your portrait subject on. People sway when they are standing, which is a nightmare when you're shooting with a thin DOF. Buying a decent stool made more difference to my portraits than better lenses or better loupes.

Kevin Crisp
6-Mar-2017, 12:05
Coincidentally, I haven't used my Symmar APO 210 in several years, but took it out this weekend for a photo I needed it for on 5X7. Abandoned church with an interesting horizontal sign on the top front of a porch. On the top of the building maybe 25' back, a crooked white cross. I focused on the sign, which was fairly close to the camera. The cross was out of focus. A little tilt brought the cross almost into focus. Just to be sure closed down to between f:32 and 45. Negative is plenty sharp enough for any size print I can make. I'd have never given it another thought but for this thread. Probably by focusing appropriately between near and far I could probably have gotten away with one more stop open. But this was less trouble.

Is this the sharpest aperture for this lens? No. But it doesn't make any practical difference with my real world parameters. If you're shooting for 10' tall murals, that's another story. 16X20 is currently my maximum print size and that is not pushing a 5X7 negative very hard.

Taija71A
23-Mar-2017, 17:05
I took one @ 5.6 and the results were soft. I guess I need to start taking meticulous notes...


I'm just going to shoot @ 5.6. Seems like the pursuit of sharpness is a dangerous one.


Did you NOT LEARN ANYTHING? 5.6 is for FOCUSING NOT SHOOTING! ARGGGGG!!!!!!!!!!!

Exactly!

If you want 'Soft' Results along with minimal DOF... Shooting 'Wide Open' -- Is where it is at.
Otherwise... You would be 'well guided' to perhaps re-read many of the posts... In this Thread.