LF lenses: are they really sharp?

[Paul Schilliger]

I recently had an opportunity to shoot a 150 strong group of people with a building in the background. I made a few shots on a 6x12 rollfim back with the 110XL at f16 and I secured the taking with the Pentax 67 and a 75mm lens at f16. The 6x12 shots are so weak compared to the 6x7 that I am contemplating throwing my 4x5 outfit into the lake. I am joking of course, no use of writing to me privately to offer adoption. But by the time I shot with the Pentax, people were a bit weary and so I have to use the 6x12 shots. If film flatness or focus were the problem, I would see some sharp and unsharp portions of film as the depth of field started at a dozen yards and reached infinity, but the film is just evenly unsharp. When I say unsharp, I mean it's decent, but unsharp compared to the 6x7 shots. I always thought the 110 XL was a sharp lens, but I am quite puzzled now! Any comment?

[Arne Croell]

Paul, can you elaborate a bit more on the differences and the conditions when they are visible? For example:

At what magnification is the difference discernible? Is it more a resolution or contrast difference, or both?

If its contrast, the one explanation I can offer is that the 110XL has a huge image circle compared to the 6x12cm format you used which leads to a lot off non-image forming light bouncing off the inner walls of the bellows reducing contrast - unless you used a compendium in front of the lens.

[KenM]

I've heard that earlier versions of the 110XL did have sharpness problems, but this was addressed in later versions. Perhaps you have an early version of the lens? I have a 110XL (purchased new just over a year ago), and I've never had anything but sharp images from it.

[Gem Singer]

Hi Paul,

The Schneider 110XL is a very sharp lens. However, F22 (or a smaller aperature) probably would have been a better choice than the f16 aperature you used. Of course, it could have been your eyes, when you focused on the groundglass. My guess, look for your rollfilm back to be the basis for the problem, not your lens.

[Paul Schilliger]

Arne, the difference is in resolution only, both type of shots look exactly the same until you zoom in right into the faces of the people. Then it becomes evident that the 6x7 shots have a lot more to them. Well, I always knew that most MF lenses are sharper than LF lenses just as SF lenses are sharper than MF lenses. It's just that I am surprised to see that a panoramic crop representing half the film surface of a 6x7 contains more detail than a whole 6x12 frame!

[Paul Schilliger]

Eugene, you are right about f22 being a better choice. It was dimm and I was already at 1/15 on 400 ASA Provia. A curved or popped film should show at least some sharp areas I suppose. Ken, my sample is an early one... I must say that my 4x5 shots always satisfied me and gave me an impression of sharpness. It's just that I am suddenly aware of how sharper are the MF lenses!

[Ralph Barker]

Assuming the on-film magnification factors are similar, I don't think the 6x7 vs 6x12 is really a "crop" in the sense that you're making the comparison, Paul, as it's essentially just cropping off the sides.

Given your situation, I'd also suspect the 6x12 rollfilm holder as being the source of the problem - potentially both in terms of film flatness and in positioning with respect to the ground glass.

[Arne Croell]

Your description suggests a difference of at least a factor of 2 in resolution - that is more what I would expect, and also more than what the numbers on <a href="http://www.hevanet.com/cperez/"> Chris Perez's web site <a> suggest. My suggestion would be to repeat that "test" (without the people of course) under more controlled conditions and check again.

[Jim Galli]

You've measured film plane vs. ground glass with film in the back? Sometimes we make the "leap" since there's no problem with film holders and just put something like a 6X12 roll back in and figure surely it's "right on" especially considering what you paid for it. I'd check with a Starret last word type dial indicater and prove that the film is indeed at the same plane as the ground glass. At F16 that Schneider should resolve almost identically to the 75 P67. I just had the same thing happen with the 8X20. But luckily my big neg is robust. But like you by the time I got to the smaller camera people were picking their noses etc. etc.

[wfwhitaker]

Sounds like you never were really in focus to begin with. As Ralph and Jim suggested, check your ground glass alignment.

[Bob Salomon]

Paul,

Get a back copy of Color Foto the March 1992 issue and see the article ScharfSchützen. Pages 99 to 104.

[George Hart]

Paul, there are so many variables here that it could be possible to pick any and to suggest that it is responsible. Without more testing, we're just guessing. I have shot quite a lot of rollfilm with the 110 XL lens and also with dedicated MF cameras, and my experience corresponds to the test data (see eg Arne's posting) suggesting that you usually can't blame LF lens resolution! Going to f/22 will cut rather than enhance resolution in the centre of any lens, but on one criterion, resolution with the 110 at f/22 would be equivalent to a 75 at f/16. You may have focussed on the same spot with both cameras, but I am surprised that one of the variables that even some LF practitioners don't get right is just where to focus. IMHO, the "hyperfocal distance" method is seriously misleading. Basically if there are objects at infinity and you don't focus at infinity (>200x lens focal length), then those objects will not be in focus. And with a composite scene involving both infinity and close objects, it is usually better to focus at infinity and then to stop down as required. Any help?

[Ted Harris]

Onemore thought, think back .... you were shooting at a 1/15th ... were there any possible vibrations, any wind, etc? The 100 is my most frequently used lens and I have no problems with it and it is a relatively early production model ... as I recall the problems were with the early 80's not the 110. meanwhile, I frequently shoot with a Noblex 150 F at the same time I am shooting 4x5 or 8x10 and frequently the Noblex images are as sharp as those from the LF but I can;t say they are ever sharper or that they will hold up as well in large blow ups.

[Leonard Evens]

Using a coc of .1 mm for a 110 mm lens at f/16 with a 6 x 12 format yields a hyperfocal distance of about 25 ft. Using a coc of 7/12 (.1) mm for a 75 mm lens at f/16 with a 6 x 7 format yields a hyperfocal distance of about 20 feet. But looking at both at the additional magnification necessary to see detail in the faces would multiply the hyperfocal distances by that magnification. So it is quite possible that under the viewing conditions you describe, the faces were still in focus for the 75 mm lens with the Pentax and just out of focus with the 110 mm lens with the 6 x 12 roll film holder. As others have pointed out, you probably should have used the 110 mm lens at f/22, or using the 12/7 factor possibly even one half stop beyond that. Of course there could have been a multitude of other factors such as problems with the position of the film plane.

[Paul Schilliger]

Bless your hearts! You are reassuring me about the LF lenses quality! I just went through the scans again and I think, as some pointed that it was a lack of precision in the focussing. It was dimm and even with a good loupe, focussing started to be critical. Focussing with the Pentax was much easier. As Leonard pointed, with the 6x7 the DOF reaches the whole bunch of people and even the wall behind whereas with the view camera and larger image size, the wall starts to be out of focus at the base (I used some tilt). Anyway, you are all right in that there are so many variables and that a real test should be carried in more rigorous conditions. But for me one thing is sure now, when light is scarce and people are involved making it impossible to use long poses or to check the foccussing between two shots, MF has the edge and is safer.

[Michael Kadillak]

This is a comment for Bob Salomon.

Bob you are a wealth of information and if mention is made to an article from a 12 year old magazine, recognizing that it is highly unlikely that even Paul will find the time to locate it, could you at least throw us a bone and give us an executive overiew of the authors conclusions? Then maybe we could find enough incentive to injest the contents. Just a friendly suggestion.

Cheers!

[Bob Salomon]

The large format lenses outperformed all medium format lenses from Rollei - SL66 and 6008, Hasselblad - 500 and 2000, Fuji 680, Mamiya 645 and 67, Pentax 645 and 67. Bronica 645, 66 and 67.

Lots of tests and conclusions. If you read German I can mail you a copy. If you do not read German I can still mail you a copy and you can look at the test results.

[Henry Ambrose]

Paul, Look at your film again. Somewhere in the frame is the actual plane of focus (we hope) See if that is sharp or not - thats the real test - seeing if THE plane of focus is sharp. A good way to demonstrate this is to scan the film at high resolution and examine it at actual pixel size on your monitor. You will find the plane of focus and you will see critical focus slipping away as you look away from that plane. Stopping down would more than likely have helped you - I know my 110 is better at f22. But I understand that you needed shutter speed more than the extra stop.

[Frank Petronio]

Between depth of field and film flatness, I found a 6x17 pan camera sharper than 4x5 in practical use - ASA 320 Trix at 1/60th and f/8 - for outdoor group portraits where I needed a decent shutter speed in open shade.

[Ken Lee]

"6x12 rollfim back ..."



One



"It was dimm ... "



Two



"(I used some tilt)... "



Three



Sounds like you did pretty well, considering the odds.

[Mark Windom]

I have done alot of shooting with the P67 and with LF using Horseman 67 roll film backs. When comparing identical subject matter using the Pentax lenses and a variety of LF lenses including the 110XL I can't see any difference between the two under a 4X Schneider loupe.

As many have already suggested I doubt your lens is to blame. Someone mentioned that early versions of the 110 were "soft". I had not heard that as pertaining to the 110 but I had concerning the 80XL when used wide open making it difficult to focus.

The roll film back is the most likely source of your problem. Can you do a similar comparison using a different, preferably a Horseman 6X7, roll film back?

[Desperate Sam]

I've shot with the P67 and 75lens (2.8 version), and the 110xl on 4x5, with the same subject - landscape. The 110xl even at f16 is very sharp (ignoring depth of field requirements), and I found it so be similar to the 75 sharpness (at f11). The 110 took in a larger field of view than the 75mm on 6x7, but overall the subjective sharpness was very similar. In general, I found that the same focal length lens on 6x7 (say 200mm P67 vs 210mm Nikkor on 4x5) was sharper than a similar focal length on 4x5 (but recent top-of-the-line Rodenstocks and Schneiders would probably do as well the 6x7 lenses), but that's kind of an apples and oranges comparison (field of view/angle of view difference).

My guess is that either your focus was off (due to dim light, or lack of high enough mag loupe - I find 4x not good enough for particular details in dim light; I use a 7x Calumet loupe for most of my 4x5 work), your groundglass it not aligned perfectly, or/and the roll-film holder doesn't place the film in exactly the right place, or the film holder does not hold the film flat enough. Also, the lens tilt could have messed things up.

I have done extensive tests comparing 4x5 sheet film in Toyo holders to Fuji quickloads, and I went back to Toyo holders, after seeing how inferior the quickload film flatness was. Won't make a difference to most shooters, or in smaller than 16x20 enlargements, however. Different brands of roll film holders, or a different sample of the same type as you have might make a diff. If you were interested in still pursing the 6x12, doing a test in bright light, carefully focusing on a subject at primarily one distance, and using fine-grained transparency film on the 6x12 and on the P67, and then viewing the trannies with a decent quality loupe of 6x or more, should tell you.

[Bill_1856]

Paul, it just occured to me that you shoot with a Technika. If you have trouble focusing, you might consider having your 110 lens cammed for the rangefinder.

[Colin Myers]

Paul, Not sure if this is relevant in your case, but I heard recently that for the whole range of Schneider Super Symmar XL lenses, the mounting into the shutter is super critical. This is set at the factory and if the lens cells are removed for any reason, it would almost certainly require a trip back to Bad Kreuznach to rectify the problem. Does this strike a cord?

Colin Myers

[Paul Schilliger]

I just went through all the shots again and the culprit suddenly appeared to me! I have to revise my hasty conclusions.

It came back to my mind that when I set the camera, in order to align the roof, I used some lateral shift (I didn't use tilt at the same time). At this point, I should have swapped the standard bellows for the WA one. I didn't and the result is a bad alignment of the back and front standard due to the strain of the bellows (I used the Toyo this time, Bill, and a Sinar Zoom film holder) . In fact the 6x12 start very sharp on the first cm or two, absolutely comparable to the 6x7 shots from the Pentax, and they go softer on the rest. The dimm light didn't allow a thorough checkup and that's what happened. Now I see, when I compare what can be compared, that the sharpness of both systems and lenses matches each other. But apparently, there wouldn't be too much gain in using a 6x12 film format instead of a 4x7 (6x7 crop), other than a larger scan area.

It was good to check that with you guys, and thanks a lot for all the brain storming and the ideas that came up! Above all, it's good to kow that carrying the big gear is still worth it!

[Ed Burlew]

I have shot with the 210xl on 8x10 and I have no problem with very high resolution even whn enlarging to five feet by seven feet! the 240 rodenstock sironar n is very sharp and I have been able to make out individual tree leaves on trees two miles fom the camera in 30x40 ull frame enlargements. Of curse I was meticulous regarding focus and tripod stability.

[J. P. Mose]

Paul,

I know this is way late but I happen to stumble across this posting. A very similar situation happened to me three years ago....I brought my Linhof to an off-site business meeting my company conducted. I thought it would be nice to take a department photo to hang in the office. I used a 150mm Symmar at f/22. The negatives turned out very soft! I could see that everyone was in proper focus but it appeared as if I used an Imagon. In the end, it turned out to be resonance from the tripod (I think I shot at 1/15). I was using a Tiltall at the time and had the legs completely extended. There was a light breeze that day. Although I have used my Crown Graphic successfully with the Tiltall, the Linhof seems to require a bean bag or some weight to prevent vibration. I have since purchased a larger tripod but still use some form of dampening to prevent this from happening again. Any possibility this could have been a contributing factor in your situation?

Regards,

J. P. Mose

[Paul Schilliger]

John P. , The problem of a weak tripod is often overlooked, but in that case it was not: I have used a very stiff headless video tripod that I use for long extensions too. But as I mentioned above, I could trace the problem to a lack of alignment of both standards due to the strain of using a normal bellows with movement when I should have used the bag bellows. The prints are OK, well some faces on one side are not very sharp. It could have been worse.