Schneider Super-Symmar 80/4.5 XL - NOT sharp???

Getting back into 4x5 and I have just purchased my first lens, a new Schneider Kreuznach Super-Symmar 4.5/80 XL 105 degree Aspheric MC lens - expensive bugger by my budget standards!

Within a week of purchasing it I have been told by two separate Schneider dealers that the 80 XL is not a sharp lens if used below f8! Fortunately, if true the dealer I purchased the lens from and I agreed to a return if I don't like it.

That was a surprise to hear!

Does anyone have the 80XL that can confirm or deny these dealer claims?

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 won't have my film test done for a couple of weeks to be able to run my own testing, and I want to return the lens if it is not sharp.

Your guidance is appreciated.
Jack

Regardless of what anyone has to say about this, wouldn't you want to test your particular lens and find out how it performs ? That would take care of sample-to-sample variations, as well as give you first hand knowledge. Just a thought, and hope it helps.

Regards,

Phony,

Yes, your thought is valid but as I explained in my posting, it will be several weeks before I'm set up to be able to run a critical film/resolution test.

Now, I've been out of the LF world for 15 years and I'm not up to date with what is considered excellent glass and what isn't.

IF not being sharp below f11 is a know trait of the 80XL, I would have no awareness of it due to my absense from the scene but members here would.

Thus the reason for my asking for help - ie: If I purchased a lens with a forum known trait than back it goes and the next time I ask forum members for their suggestions first.

When the first dealer mentioned the trait, I was surprised but figured I'd wait and test it. When the second dealer mentioned it last night in conversation, I felt there may be merit to the comment.

Jack

Jack,

I hope you don't call me phony as well, because what I offer is not as an expert.

I think virtually all current production LF lenses are extremely sharp. However most photographers will generally shoot stopped down at least 2 to 3 f stops. The circle of confusion and color correction improves with any lens at smaller f stops. The best designs in optics are "compromises" balancing the entire color spectrum and there is no such thing in this world as a "perfect" lens.

In addition all lenses have light fall off due to geometry of how far from the central axis the light ray path is. Add to this that at wide open apertures, there is often mechanical interference at the outer edges of the image circle which further reduces the amount of light out there, and you may want to start using a central grad filter.

The above are some reasons for not shooting at full aperture, especially with very wide angle lenses.

I tend to think of fast wide angle lenses as providing me with a much brighter image for focusing purposes. Otherwise, I would be glad to carrying much slower and lighter lenses in my kit.

Other than that, if you don't like the 80 XL, which I would love to have for it's extreme coverage. What else would you buy???

As Wilbur pointed out, the geometry of lens design ends with a lens with an optimum aperture. While someone with more knowledge can flesh this out, the optimum aperture is generally two stops down from wide open. It's my recollection there is usually only one and for example, in process lenses, its f22. Most others are f16. I suppose this brings up the other question, what is "sharp?" I agree with Wilbur you need to find out for yourself. As a side note I'd be interested to know if the two dealers know the lens is "not sharp" by testing or talking. Fortunately you can test to see if it meets your needs and if not, return it. Good luck.

Mike

Schneider had some QC problems in the first production run of these lenses but that was around 5 years ago. No one has reported any problems since.

I can't imagine there is any lens that will shoot as sharp at f8 as it will at f16 or f22. The other lens that has a great reputation near your focal length is the Nikkor-SW 90mm f8. It's a great lens, but some complain about trouble focusing at f8 and of course it really comes in to it's best performance at f22.

If the Schneider 80mm doesn't work for you, then I'd say you're out of luck.

-Ben

Is "not sharp" a misnomer of language or misplaced euphanism for out of focus? ie limited depth of field?

Opps, Sorry Phong, old fingers and a weak mind here!
I have my moments of brilliance, that was not one of them.

Jack

You are at the mercy (or lack thereof) of the accuracy of your filmholders tolerances, as well as those of the filmback itself. Furthermore, film can have a tendency to rest slightly above its assumed plane of focus. There are ways in which camera manufacturers can take some of this into account, but you still should probably assume that while photographing at wide open or near-wide open apertures, even with a "theoretically perfect" optic, at least with respect to your wanting a specific plane to come into focus, you will experience some inconsistencies into your results.

Keeping the above in mind, here's what I suggest. Tape some newspapers flat to a wall, and photograph this at a wide aperture, flat-on, then take a second photo of this newsprint, but from a slightly oblique angle, noting as you do where your zone of good focus should be from the text on the newsprint, and see if this corresponds with your actual results. The second photo will tell you something about the resolving power of your lens in a given location, as well as the "accuracy" of focus, while the first photo, assuming you have this accuracy, will tell you about edge to edge sharpness.

If you do this test or something similar, I'd be very curious to know the results. Good luck!

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.

"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.

Your two dealers are about four years behind the times. As Bruce indicates, there were some problems with some of the lenses in the first production run of the 80mm SS XLs. That started a lot of discussion, some of it here (which you should be able to find if you search), about the lens not being sharp. Schneider quickly fixed whatever the problem was and as far as I know all 80mm SS XLs since that first run have been fine. I've owned mine for about two years and it's a great lens, tack sharp at any aperture I use (I don't use it at f4.5 except to focus).

Excellent exchanges - thanks to the group for your thoughts.
I'll spend tonight digesting all of this info.

Is there a standard test pattern/chart that is recommended for running my personal test of the lens?

The Jobo Expert 3006 drum arrived today so I can be up and testing shortly.

Thanks again to all who contributed!
Jack

My suggestion for a test chart: a brick wall. This works well for a qualitative test -- why do you need to know line pairs per mm resolution? Just get your camera perpendicular to the wall (levels and ground glass grid lines or edges compared to the bricks are helpful) and take photos at the apertures that you might use the lens. Apply the largest front rise that you might ever use (or the equivalent shift, if more convenient). Compare the different apertures, and the edges against center, to see whether the sharpness meets your needs / wants. You should see the coverage increase with decreasing aperture (larger f-number). Be sure to make your judgements at the largest enlargement that you will use, or with equivalent loupe power.

i tested my 80xl for hand held use and made 2 shots 250 sec on f8 and 250 on f11, this lens is soft at f8, and you don't have to be a lens expert to see it, oh, and yes i have a new version.

but at f11 or > this lens is amazing, i woudn't give it back if i were you, i am making 54x70" mural prints of a series of pictures made with this lens and they are exceptional.

I'm not sure if most people are aware that the wider the lens, the deeper the depth of field, but the smaller the depth of focus, i.e., the focus at the film plane. So any evaluations of the lens wide open would have to include how accurate the relationship of the ground glass is to the film plane. And just as the lens gains depth of field when stopped down, the depth of focus also is increased. With "normal" or longer lenses this generally isn't a problem since the depth of field (what's in front of the lens) is less, but the depth of focus (the focus at the film plane) is greater. I'd buy one of the problem lenses in a heart beat since the issue probably isn't the lens but the tolerances of the camera and the operator.

Kind Regards,

MW

Mark, it is a common belief that depth of focus is smaller for shorter focal length lenses, but the equations don't agree with this. For distant subjects, the equation simplifies to depth of focus = 2 C N, where C is the diameter of the circle of confusion and N is the aperture (f-number) -- the focal length doesn't appear in the equation. Maybe the idea comes about because smaller formats have smaller depth of focus, because they have smaller circles of confusion on the film, because greater enlargements are needed, and this gets associated with the shorter lenses used on smaller formats.

Michael Briggs wrote "My suggestion for a test chart: a brick wall. This works well for a qualitative test -- why do you need to know line pairs per mm resolution? "

Michael, a brick wall or anything else with a regular pattern will do fine for a go/no go test if the pattern's spatial frequency matches that of the finest detail that will have to be resolved when a "real" picture is taken. The advantage of test targets that have more than one spatial frequency is that one of the frequencies on the chart will probably be close to what has to be captured. This is why the test shots on, for example, Klaus Schmidt's macro lens site are not particularly informative.

Cheers,

Dan, the brick wall test works well as a qualitative test -- give it a try. The key is that the "test chart" has uniform detail over the entire subject area, so you can see how the sharpness of the lens varies over the film area. You won't get a quantitative measure of resolution. It isn't necessary that the brick size match a spatial frequency of interest -- you can look at how sharp the edges are, and how details on the bricks are rendered. Of course, the farther the you get from the brick wall, the finer the details will be. It's only a qualitative test. One advantage is that the subject is distant, similar to the subjects the lens will usually be used for.