As Wilbur points out, some of the image will be sharp at 4.5 and some of it won't be due to limited depth of field. If 4x5 film was the size of a postage stamp, you'd have a lot more depth of field at 4.5...but it isn't.
As Wilbur points out, some of the image will be sharp at 4.5 and some of it won't be due to limited depth of field. If 4x5 film was the size of a postage stamp, you'd have a lot more depth of field at 4.5...but it isn't.
In general, large format lenses are not designed to use f/8 as a working aperture, although the newest plasmat designs can be quite decent when abused in that way - the Apo-Sironar-S holds up pretty well at f/8, and I wouldn't be surprised if the Apo-Symmar L does as well. (The Apo-Sironar Digital series is optimized for f/8-11, but will only cover roll film formats at those apertures.) I wouldn't expect quite so much of the SS-XL, because that design is really optimized to achieve very large coverage in a very small package, and indeed there have been prior reports that the SS-XL series are excellent at standard working apertures, but that the wider apertures are really for viewing only. Of course, a lot depends on what your expectations are for image quality.
I would give you the standard advice to run your own tests to see if the lens meets your needs. However, it seems to me that the real problem here is that if your plan is to photograph distant landscapes with a short focal length like 80mm at f/8 on 4x5, there is a fair chance you are going to run into film-register issues regardless of how good the lens is. Depth-of-focus is going to be really narrow in that kind of usage, and 4x5 film holders are not exactly high-precision devices. At the very least, you will need to test your camera to make sure that your ground glass and the nominal film plane are in precise register, and even then, you may find that there's enough variation in film positioning from holder to holder or from one loading to another that it's difficult even to run a reproducible test of the performance of the lens at such a wide aperture.
Jack wrote in part:
"I shoot landscape with slow speed B&W films and then drum scan at 8,000 res - I need very wide aperatures to get the low light images that I enjoy and I was please to find an f4.5 lens! But if the f4.5 is of no use, then the lens goes back."
I can tell you that my 80XL is not sharp at f4.5. Not because I've shot any film at f4.5 but because I can --see it-- on the ground glass. But when its stopped down (as is my normal use) its plenty sharp - its one of my most used lenses.
Have you mounted the lens on your camera and looked at the ground glass image?
Is there a reason that you can't stop down and use longer exposure times? You're not shooting handheld with a Leica!
For what its worth, I doubt that --any-- wide lens for 4x5 is going to be sharp across the field wide open.
One final point - the SS-XL design loses a lot of coverage at wider apertures, compared to its specification at f/22. If you look at Schneider's MTF data...
www.schneideroptics.com/photography/large_format_lenses/super-symmar_xl/pdf/super-symmar_xl_45_80.pdf
...you can see just how much is lost at f/4.5 and f/8 compared with f/22. Even if you can get good film register, you are likely to find that there's not much room for movement at f/8, and performance at the corners may be iffy.
Again, the SS-XL is a very fine lens when used within its design parameters. Per Henry's point, if you can stop down a bit further it should produce excellent results.
This is a link to resolution test data for many current LF lenses, including the 80mm XL. Three early production samples of the 80mm XL were tested. One was too soft.
I have read elsewhere that the QC for this lens has since been improved.
http://www.hevanet.com/cperez/testing.html
For what its worth, I doubt that --any-- wide lens for 4x5 is going to be sharp across the field wide open.
And I doubt that most would use it wide-open even if it were sharp.
But, let's talk about this. There are wide LF lenses that are sharp wide open. Maybe we could pull together such resources in a list.
I bought an 80 XL about 4 years ago, don't know if it's considered an early production one or not, but I can tell you that it is nearly impossible to focus this lens anywhere in the field of view unless I first stop it down at least one stop. Wide open it is very soft, much more so than any other lens I own. However, once I stop it down to f8 it is easy to focus and at the apertures I use for landscape work (16-32) it is extremely sharp.
If you haven't already, look at the schneider link that Oren posted. he's right; this lens (like most LF lenses) was not designed to be sharp at f8 or wider. It's one of the qualities they were willing to compromise to make the lens sharp in the range where most people will actually use it.
I bought a used 80mm SS-XL last year. Mine is very sharp indeed. I focus at f/4.5 using about 5x loupe, and it's nicely sharp there. I've made photographs at f/8 and the negatives look quite sharp on the light table with a 10x loupe. I haven't made any prints bigger than 55 x 68.8 cm, but these prints are as sharp as I could want.
Early production of this lens resulted in some that were soft at f/4.5 and difficult to focus and basically worthless until about f/16. I seem to recall something about spacing errors in manufacturing that were identified and corrected quickly. Anyway, my lens was one of those early soft lenses according to the previous owner. He sent it back to Schneider who fixed it and returned it in its current very sharp state.
Mine is just as sharp as it's 110mm SS-XL brother. I take them both everywhere I take the camera. I just wish I had occasion to use it more.
As to the Schneider dealers telling you that it's soft above f/8, I have to question whether they are just spreading rumors or whether they actually shoot with the lens.
Bruce Watson
"But, let's talk about this. There are wide LF lenses that are sharp wide open. Maybe we could pull together such resources in a list."
looking at published info from both companies, rodenstock grandagons in general seem to be a little sharper wide open; schneider lenses seem to be a little sharper at f16 or f22.
also, the older super angulons seemed to be a bit sharper at f8 (which was wide open for a lot of them) than the newer super symmar xl lenses. but the new lenses are sharper at closer focusing distances (like 10X) than the super angulons. seems they're just trading one thing for another when they design these things. the big gain with the new schneiders is being able to focus at a nice bright aperture, and being able to cary about a pound less glass.
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