Loss of quality using 8x10 lenses for 6x9?

[m.bruehl]

Hi everybody,
today I'm taking pictures 4x5, and I also use roll film backs 6x9 and 6x7. As I plan to upgrade to 8x10, I am looking for replacement for my 4x5 lenses, that don't cover 8x10.
Do I have to expect a loss of quality if I use 8x10 lenses with my roll film backs?
Regards

Michael

[IanG]

That will depend entirely on the lens.

Undoubtedly older lenses designed for 10x8 won't have been built to the same tolerances as lenses for smaller formats, but with modern lenses you'd need to run a test and see.

A 240mm Symmar or Sironar would be superb on any format. But would a 165mm SA be as good as a 150mm Symmar.Sironar on smaller formats, it probably wouldn't even fit.

There will only be a few lenses you can use on 10x8, 5x4 & 6x9.

Ian

[John Berry]

If you are talking about a 90 4x5 vs 90 6x9, like quality might be hard pressed to see a difference in an 8x10 print. If you are talking about using long lenses on 6x9 remember larger circles of confusion will apply. Think along the lines of about 4x enlargement from an 8x10 neg, cut your print out of that. If you can hang with that, you in the good. I have shot my 24" red dot on 6x9 and have not been disappointed. You might give a little more thought about what the optimum stop would be before diffraction comes into play. I remember Sandy king using a program that would give the optimum f stop before diffraction, with the format, lens, and print size info entered.
It was part of the BTZS program, if I remember right. ( don't bet your retirement on my opinion though )

[Brian K]

Why not just test your lenses and see which perform well with 6x9cm film?

[Dan Fromm]

As everyone has said, it depends on the lens. FWIW, I use some process lenses (Apo Nikkors, Apo Saphir) that cover 8x10 on my 2x3 Graphics and they're fine, just fine.

[Walter Calahan]

Only you will know 'cause we can tell you how your tools will work with your personal vision.

[Ken Lee]

It has been said that the human eye can resolve around 8 lines per mm. That's when someone really strains to read a test target, I presume.

A really good Medium Format lens of modern design might get up to 80-100 lines per mm at best aperture, allowing a 10x enlargement or more. The average viewer is not going to step up to the image and count tiny lines, if you know what I mean. So larger prints are possible in many cases.

Very good lenses for 8x10 will get somewhere around 60% of that resolution in the center of the lens coverage. This suggests that you can enlarge around 6 to 8x and still retain critical sharpness. More so, if the subject is not a test target, or other finely detailed item.

I have made many lovely 11x14 prints (http://www.kenleegallery.com/html/tech/sixnine.htm) from my 1950's Agfa 6x9 folding cameras, whose simple Tessar-style lenses are of moderate quality at their best. As long as I choose my subject-matter appropriately, the images sharp enough even for my Large Format eye. Normal people never have never complained about lack of detail in these photos. Since they are used to digital and small format quality, they marvel at the smoothness.

[Chuck Pere]

Are you planning to only use long lenses with the roll back? Not sure many 65-100mm lenses cover 8x10 except some very special ones. Also you might want to use a lens shade to cut off excess coverage to keep reflections down.

[eddie]

are you planningt o sell all your 4x5 lenses and only use 8x10 stuff? will you stop shooting 4x5? i ask becasue you could still keep your best 4x5 lenses and when you shoot roll film or 4x5 on your 8x10 camera you could just use those lenses.

personally i would keep a small 4x5 for when it is needed. it is much easier to carry around and use a 4x5....but you already knew that.

eddie

[David A. Goldfarb]

Lenses that cover 8x10" are often in larger shutters than lenses that cover 4x5", and they have lots of excess coverage, so while they can be handy for, say, architectural subjects requiring lots of front rise, they also are more prone to bellows flare on a small camera, so they are best used with a compendium shade.

I've got a few lenses that I use on both 4x5" and 8x10" (and larger), but even though I have lenses of similar focal length for both, I often stick to the 4x5" lenses for 4x5" and smaller.

[ic-racer]

I think the most important thing is to be conscious of your aperture. If you are contact printing the 6x9, then you will probably find it OK to use f45 on your 8x10 lenses, just as you would making an 8x10 negative. But if you plan on enlarging the 6x9s then you will probably find f45 not sharp enough (from diffraction at that small aperture). Use f11 or f16 as you would any other 6x9 lens. Since you are just using the center of the 8x10 lens, any aberrations at the edges (from that wide an aperture) may not show up in the negative.

Like others pointed out, you may have to experiment to see if the results are acceptable.

My personal experience was that using my 8x10 lens (210mm) on my 6x9 horseman, produced great negatives. My longest "6x9" lens is the Horseman 180 telephoto, and the 210 compared favorably with that lens.

[Dan Fromm]

ic-racer, it really depends on the lens. My 420 and 480 Apo Nikkors are sharp enough wide open to be usable on 35 mm, not to mention 2x3. Same is true of my 360 Apo Saphir, although it is better from f/16 down than wider open. And if the 210 Konica Hexanon GRII really covers 8x10, well, all of the above goes for it too.

David, the lenses mentioned above, also many of the other lenses I shoot on 2x3, are in barrel. I hang 'em in front of a #1. Vignetting by the shutter isn't a problem, although it probably would be on a larger format. But, possibly because of vignetting by the shutter (and, on my tandem 2x3 Graphic, by the between-bodies coupling), bellows flare isn't a problem.

Come to think of it, all of my lenses longer than 105 mm were made to cover larger formats. No bellows flare problems yet with the ones in shutter.

[Ernest Purdum]

There are two factors here - sharpness and contrast loss. Both are less likely to be problems with the narrow view process lenses like the ones Dan Fromm mentions. A wide angle lens capable of covering 8" X 10" would be more likely to cause difficulties, I think. With any lens of great excess coverage, there will be a lot of light coming in the lens outside the image area. Chances of some of this light doing a bank shot off the bellows and winding up on the film are pretty high. You might not get flare, but loss of contrast would be certain. Careful use of a compendium lens shade would greatly reduce the problem.

I've been thinking of taking a 6 X 9 on a trip. If I do, I'll take a little 105mm lens for use when I don't need a lot of movements. No. it won't even cover 4" X 5", but it sure is easy to carry around.

[Dan Fromm]

Um, Ernest, the process lenses I mentioned all cover 8x10. Relative to 2x3, they have more coverage than is imaginable. But hanging 'em in front of a #1 kills most of it.

[Murray]

I think most process lenses aren't narrow view either. I haven't looked at alot of specs, but the ones I have looked at were at least 67 degrees and I think of 'normal' as 47-52 or so.

[m.bruehl]

Thank you to all!

I will keep on doing 4x5, so my lenses up to 90 mm will stay - and I know they do a good job on 6x9.

I was just thinking about replacing my APO-Sironar S 135/5.6 by a Nikkor 120/8, replacing an APO Sinaron SE 150/5.6 by a Super-Angulon 165/8, replacing my APO-Sinaron SE 210/5.6 with a Super-Angulon 210/8. I also own an APO-Sinaron SE 300/5.6, which delivers results on 6x9, that keep me satisfied.

But I don't feel too good about giving away newer "APO"-lenses with excellent coating for the (older - if I'm wrong, please tell me!) Nikkor or Super-Angulons. I am somehow afraid to get effects like CA on 6x9, which hasn't been a topic up to now ...

Thanks again,

Michael

[Dan Fromm]

I think most process lenses aren't narrow view either. I haven't looked at alot of specs, but the ones I have looked at were at least 67 degrees and I think of 'normal' as 47-52 or so.Um, Murray, Apo Nikkors, Apo Saphirs, Apo Ronars (I have and use at least one of each) cover 42 - 48 degrees, depending on focal length. Same goes for Apo Artars, Apo Process Lustrars, Apo Tessars, Apo Skopars, and I bet for Apotals too. You must be thinking of lenses made for copy machines and vertical process cameras, e.g., G-Clarons, Apo-Gerogons, ...

[Dan Fromm]

But I don't feel too good about giving away newer "APO"-lenses with excellent coating for the (older - if I'm wrong, please tell me!) Nikkor or Super-Angulons. I am somehow afraid to get effects like CA on 6x9, which hasn't been a topic up to now ...
Michael, thread drift happens. We live with it.

Coatings have nothing to do with chromatic aberration. Apochromatic lenses were made long before processes for applying anti-reflection coatings were developed. The most coatings can do is increase contrast, relative to what uncoated lenses give.

Here's a paradox for you. In the 1930s cinematographers (spelled Hollywood) used quite complex lenses from, e.g., TTH. Still photographers didn't adopt such lenses in any format, even though they were on offer, alleging that the designs had too much flare and too low contrast. I've always found film much more demanding to shoot in every way possible than still and serious cinematographers ("Hollywood") much more demanding of their gear than still photographers.

What, please, did the cinematographers know that still photographers didn't? And why, please, did my pre-WWII Retina II with 50/2 Xenon take good color slides in the early '70s? What had changed?

[m.bruehl]

Dan,

thanks for the info.

I didn't want to critisize thread drift - sorry, this was a misunderstanding caused by my english. :o

I wanted to say, that CA hadn't been an issue for me up to now, that I had no problems with the lenses I have concerning CA.

Same is for the lenses: I know they are APO by design and choice of glass, and additionally they have a modern coating to improve contrast and reduce flare.

As I always use a compendium shade, I think I can handle flare, but I can't do anything about less contrast or CA or other effects I don't know of caused by the lens itself.

Still, there seems to be no basic argument against using 8x10 lenses for 6x9, as long as I take care of flare, don't step down too much and choose lenses of not too old technical standard and design.

Thanks again to all!

Regards

Michael