Sharpness of Sheet Film vs Roll Film

[John Cook]

I have always maintained that b&w sheet film presents many operational drawbacks. No sound nor motion of video, no color, no fast and zoom lenses nor motor drives of 35mm, etc.

The major, if not singular, quality which sheet film brings to the party is a remarkable ability to capture exquisitely fine detail. One often hears law enforcement people on the news lament the poor quality of digital surveillance pictures (which can’t be clearly enlarged) in bank robberies.

In my technically sloppier moments I refer to this quality as sharpness. But, as a former college kid, I am aware that the proper terms are acutance and resolution.

Twelve years ago, I worked for a friend who is even more technically anal than I am. His specialty was 8x10 Ektachrome, shot on a king’s ransom worth of Sinar and Broncolor equipment. Absolutely no expense spared. Everything absolutely perfect. Every time.

One day, while doing a food assignment for a very young Boston art director, we caught her examining the 8x10 transparencies on the lightbox, using a loupe her boyfriend had given her to inspect 35mm slides.

She declared that the chromes were “soft” and began to insist that the entire project be reshot.

It took a great deal of fancy talking on the part of the studio owner to convince her that the 8x10 chromes were already the size they would be lithographically reproduced, and there was no point in looking at them through magnification. Finally, she backed off and the day was saved.

I knew enough to make myself scarce during that discussion. But, you know, the girl had a point. Those sheets of color did not seem to my eye as “sharp” per square inch as 35mm and 120 roll film. Especially under a loupe.

There is always the chance that the film could have bowed slightly from the center of the holder due to gravity. Anything was possible, except camera movement as we lit with the mighty Broncolors.

But I sometimes wonder if thick emulsion (color especially) sheet film is somehow not quite so crisp as microscopically thin tabular grain 35mm and roll film.

After years of doing b&w exclusively, color and chromogenic images always look slightly mushy to my eye. Perhaps that was it.

What do you think?

[Jim Rhoades]

I'm a big fan of 4x5, 5x7 and 8x10 for black & white. But, but... I have this print hanging on my living room wall. It's my father, long since gone, fly fishing. I shot it with a Hasselblad w/150mm lens T-max 100 and on a tripod. He's standing on a dock and you see some dock and 8 feet of rod on a backcast. Take a magnifying glass and you can see I shot it at 1:20 according to his watch.

I think it has a lot to do with film flatness and build quality of Hasselblad and Zeiss. The film plane and focus plane of high end M/F and 35mm equipment has to be way tighter than the best L/F.

[ronald moravec]

I believe the emulsions are the same. Material used to adhere it to the base may be different amd the base is different.

Looking thru the thicker base may make it appear softer.

The lenses designed for larger formats have les resolution than those for 35mm. There is no reason for them to be as sharp as for 35mm. I must add I look at negs made from modern 4x5 lenses with a loupe for 35mm and they look sharp at 8x. I seldom enlarge them past 11x14 so they are fine.

[David A. Goldfarb]

What was the shooting aperture, and was this tabletop work? She may have been seeing some diffraction if the lens was stopped way down and magnification was high--necessary to get the required DOF on 8x10", and the side effect of diffraction might show up with a loupe, but wouldn't really matter if the transparencies were not being enlarged significantly. A better comparison would be to look at two identical sized prints or dupes of the same setup from two different formats.

[Steve J Murray]

"After years of doing b&w exclusively, color and chromogenic images always look slightly mushy to my eye. Perhaps that was it."

I've noticed that too. I always thought it was because chromogenic print materials such as C prints had to have more color layers which physically affected the print acuity. When I started dabbling in color printing with an inkjet I noticed the prints looked sharper, and figured it was because a single layer of ink droplets could have more acuity. I never related this phenomenon to a difference between sheet film and roll film, however.

[John_4185]

If you want great sharpness in LF, then a vacuum or precision back is in order. Also, shooting at plane focus wider open would help. :) Restricting subjects to those that yield easily to sharpness helps as well. Kinda obviates many of the subjects we do, doesn't it? Unless you are into aerial photography, and then all that takes is a huge amount of money and an obsessive penchant for metric cameras.

FWIW, the US Air Force and NASA has unclassified documents concerning their aerial recon efforts. Of course, a recon objective was to extract information which does not always mean 'sharp' images as we speak of sharpness, for example gleaning data using stereo images and expert brains, and then there's symthetic-aperture radar, and digital sensors. Yes, that's right, digital aerial imaging was being done in the sixties. The commitment was made quite early. By 1970, "pixels" was part of the ordinary language in certain efforts. I haven't tried to find info about those early NASA and military projects on the internet yet, but digital recon technology has been in printed literature since about 1970.

Shaprness, per se, is not why I do LF, but the challenge to maintain adequate shaprness certainly keeps me on my toes.

[Bruce Watson]

From a mechanical standpoint, you loose some and you gain some. You loose when you decouple the lens from the camera body. You gain when you shoot from a tripod. You gain some more when your design doesn't have a swinging mirror or a focal plane shutter. You loose when you aren't using roll film that you can keep under tension. You loose a bit more as your film size goes up but your base thickness stays the same. You loose a little because your LF lenses aren't as sharp as the smaller format lenses. You loose a little because LF forces you to shot at smaller f/stops and corresponding slower shutter speeds.

I think the "sweet spot" is 4x5. The film thickness is sufficient in relation to the film area that film sagging isn't much of a problem. The smaller cameras are more ridgid. The smaller cameras are also easier to work with - almost anyone can set all the movements from under the dark cloth while watching the ground glass. And film area is sufficient for huge prints from moderate enlargement factors, meaning that what sharpness you might loose, doesn't show in the prints.

It is all a trade off, so of course YMMV.

[N Dhananjay]

No pressure plate holding the film absolutely flat. Possible film movement. Typically, somewhat better resolution numbers as you go down to smaller formats. Ability to shoot at larger f-stops with smaller formats, thus less diffraction losses and wind blur etc. Theoretically, all of this suggests that the position of the film should be more accurate in smaller formats and resolution should be better.

And yet, LF seems to trump all these factors. First, smaller enlargement. Smaller format lenses may have better resolution at the negative but this increased resolution (typically along the order of about 50% for the best 35 mm lenses) does not seem sufficient to make up for the sometimes order of magnitude difference in enlargement. So, while the small format neg may be sharper, the print from it is not. Second, upto about 8x10, I have not found film movement to be a significant source of unsharpness (at least as compared to other sources of unsharpness), and as pointed out if funds permit, one could use vacuum backs etc. I suspect that while the theory may be sound, there is enough other noise in practise to swamp this small effect size. Third, keep in mind that a 1 mm error that can be quite significant in smaller formats may be much less consequential with larger formats. Finally, keep in mind that sharpness is a multi-headed hydra and all of this only addresses resolution. Other factors contribute as much to the subjective experience of sharpness and LF typically scores on these fronts. Take acutance. The lower enlargement typically translates into better acutance from an LF neg. LF also does better at holding micro-contrast (contrast in small areas). That is, little changes in tones are captured with more area in LF, whereas in smaller formats, they are sort of averaged or smeared onto the smaller area. Thus, the sensation of extremely fine detail in LF, even if that detail is less sharp theoretically.

With regards to the B&W versus color/chromogenic, I have heard others comment on this and wondered whether it was the difference between silver grains and dye clouds but have also wondered if this was a systematically discernable difference.
Cheers, DJ

[Steven Barall]

Lets us say that you are using 8X10 film and that camera is pointing down. Generally, can the most films support their own weight? That is, can the center of the film bow away from the holder? Also, are current films thicker than films from recent history or are they all pretty much the same?

[paulr]

add to the list that you're using lenses that are designed for lots of coverage ... there are optical compromises involved in doing this. if you compare MTF curves of the best lenses in different formats, you'll see a general decline in performance, all else being equal, as coverage expands. however, you might be talking about a 20% drop in MTF, corresponding to a 100% increase in linear film size, so the compromis is more than worth it in the end.

[John_4185]

Steven's question reminds me that there is a 'sticky' film holder, and one can make his own, which keeps the film from falling forward under its own weight.

[Eric Rose]

I always thought it was the glass used. From what I have read the LF lenses are not as sharp as say 35mm lenses and the expense to make a LF as sharp would be astronomical.

[Dan Jolicoeur]

Intriguing; I have noticed this and was just thinking about it yesterday during a printing session. With 35mm the grain focuser use to, well pop with grain, and sharpness. With 4x5 you can never see the sharp grain and crisp lines as you can with a 35mm negative. I can’t believe it is film flatness either because you would see some part of the negative sharp and crisp, and some of it fuzzy. I would agree with Paul that it has to do with the optics or the film base. It would be interesting to try a 35mm lens on a 4x5, and see if the image circle that you get is sharper than a regular LF lens? It would be interesting to assemble a 35mm body, or back to a LF camera also. Or is it the shorter distance from film to focal point that makes the difference?
Dan

[ronald moravec]

I remember reading there is a difference in holders too. All do not exactly place the film at the correct point, ie there are debth differences from one holder to another.

Then humidity can make the film bow.

All these problems are solved with the Sinar holders at a price you can`t afford.

[Aaron van de Sande]

It is diffraction losses. The negatives from my contax 35mm look like they were etched on the negative. 8x10 is not nearly as sharp, no matter what I do.
Don't tell me it is film flatness either because there would be areas on the negative that were really sharp and other areas where it isn't.

Arial cameras would not have a diffraction problem because there are no DOF issues and they can shoot those big lenses wide open.

[Eric Leppanen]

I've also seen in prints the "8x10 look" (great tonality but soft) and have been working hard to eliminate it from my 8x10 work.

After much experimentation, I have been able to achieve 8x10 chromes and negatives which look sharp corner-to-corner when viewed through a 10x loupe. Still perhaps not quite as sharp as 35mm or my Mamiya 7, but with color film you are doing well to get 60 lpmm so the difference is not significant. For me, the issue was not film emulsion issues or flatness. Proper tripod mounting helped (I now always use a long lens support brace, even with short lenses). But the big difference was having lenses that are well corrected for the application, benefit from relatively open apertures (f/16 and f/22 for distant subjects) and have plenty of coverage (so that one is shooting through the "sweet spot" of the lens most of the time). Unfortunately this equates to big, modern, expensive 8x10 glass (read Super Symmar XL's, plasmats and a relatively exotic telephoto). So I use the big glass close to the car, and my lighter Fuji-A's and C's for hiking.

Smaller apertures (f/32 and smaller) reduce but do not eliminate the differences between lenses in my experience.

[Mark Sampson]

"Acutance". Well-defined grain edges look sharp. Ask anyone who uses fast 35mm film and develops in Rodinal. Of course it's an illusion, and masks the lack of detail; but to the non-discerning eye it looks good, and perhaps more pleasing, than the smoother, more hi-res large-format image. People have claimed not to like TMX-100 for this very reason- too much resolution and not enough micro-contrast.

[John_4185]

Eric Rose I always thought it was the glass used. From what I have read the LF lenses are not as sharp as say 35mm lenses and the expense to make a LF as sharp would be astronomical.

Well, one can get outstanding glass that was exceedingly expensive - former government lenses used for mapping and recon, and not all of it terribly old and outdated. Of course, some have no diaphram, and the shutters aren't easily transported to LF, and the lenses tend to be very large, but those are not obstacle to the, ah, obsessed?

[Ted Harris]

I haven't read all the responses in detail so forgive me if I cover ground that has alrady been covered. The main point is that the 8x10 trannie was already at it s presentation/use size. You woul dhave needed to make an 8x10 enlargement of the 35mm slide and then do a side-by-side comparison to make this accurate.

John, why not actually do it and see what you think?

[Dan Fromm]

Eric Rose: I always thought it was the glass used. From what I have read the LF lenses are not as sharp as say 35mm lenses and the expense to make a LF as sharp would be astronomical.

jj: Well, one can get outstanding glass that was exceedingly expensive - former government lenses used for mapping and recon, and not all of it terribly old and outdated. Of course, some have no diaphram, and the shutters aren't easily transported to LF, and the lenses tend to be very large, but those are not obstacle to the, ah, obsessed?

Um, guys, a while ago I got a 210/9 Konica Hexanon GRII. I was so impressed by what it did for me on my tiny little 2x3 Speed Graphic of nothing at all that I shot it against my 200/4 MicroNikkor AIS. In test shots at ~ 45' and at 1:2, at f/8 (MicroNikkor) or f/9 (GRII), f/11, and f/16, both lenses on a Nikon. The GRII won at both distances and all apertures. If the GRII were a bit easier to use on a Nikon, I'd retire the 200 MicroNikkor.

Not all decent lenses for 35 mm are sharper than all decent lenses for larger formats. And the decent lenses for larger formats need not be particularly exotic.

In the last year I've sold three 240/9 Dagor-type G-Clarons. Before I sold 'em, I shot each on a Nikon. Damn! they're good.

Cheers,

[Christopher Perez]

This is a rather interesting conversation.

Film is the resolution limiting factor. Period.

I'm thinking the trollup who looked at the 8x10 images didn't know her head from a hole in the ground. But... I suppose that early chrome material might not be as sharp as newer films. Still, same emulsions and all that for what's availble today, regardless of the format or base thickness..

Regarding lenses, I see no difference on film between the various formats. Sure, a couple of my 120 format cameras can lay down 120+ l/mm to film and give outstanding contrast in the process (to give that enhanced "apparent" sharpness "look" and "feel"). I'm sure that well manufactured 35mm glass can do the same. But by the time an image is enlarged to 11x14, grain starts showing up. Even when using TMax100. At 11x14 enlargement and greater LF wins the day in terms of resolution, "apparent" sharpness, and lack of grain.

[Ralph]

Very interesting discussion.

1) I think Christopher Perez's tests (on his website) show that the best smaller-format lenses almost without exception have a higher resolving power than the best larger-format lenses (Christopher was able to reach 120lp/mm with the Mamiya 7 80mm, and I think the best he could do with a large-format lens was in the mid-70s). None of this comes as a surprise to 35mm shooters, Leica and otherwise, who know that attaching a medium-format lens to their camera rarely if ever results in the same sharpness as a dedicated, sharp 35mm prime does. If it did, there'd be a run on used Hasselblad and Rollei lenses by full-frame digital SLR users. (True, in large format, certain govt.-spec lenses and some of the new small-image-circle digital-intended lenses are exceptions to the automatically-lower-resolution rule, but neither is in common use, for example, by 8x10 photographers.)

2. My reading of the original post was not "Which will produce a better 16x20 print?" -- of course large-format will beat 35mm every time -- but "Which is sharper PER SQUARE INCH of film?"

That's what the "trollop" saw on the light table, and I think it's a valid question: if you took a 24x36mm section of 8x10 film and enlarged it, would it outresolve a similarly enlarged full frame of 35mm film shot using a prime lens? I can't think of any circumstances in which it would.

Like the original poster, I've been struck by the "softness" of large format sheet film, despite doing everything possible to ensure flatness and sharpness: Rodenstock-Apo-S lenses, Quickloads with even pressure plate to prevent film sag, focusing bracketing, and all; none seem to result in anywhere near the resolution *per square inch of film* that a good 35mm or medium-format combination does.

It is only because we don't usually enlarge as much as 35mm-users do (for example, a 16x20 from 35mm is equivalent to enlarging 8x10 film to something like 11-feet x 14 feet) that we don't see the softness.

[Christopher Perez]

Furthering the interesting discussion...

I think it would be a valid test to confirm for our selves that thickbased film can resolve what the thin-based films can. In my tests it does. For a std. 6:1 contrast scene using the finest grained B&W or color films (all modern) the limit is 140 l/mm. Per square inch, film resolution is the same regardless of base thickness.

Now lets consider what a 60 l/mm LF lens will do compared with a 120 l/mm MF optic: In my experience there is NO WAY that a trollop with a 8x or 10x loupe would be able to tell the difference between the two. If said trollop could, she must have truly incredible non-human eyes. Or other contributing assets.

In my situation, I made absolutely certain that the LF groundglass and film holders are in spec. In fact, my 4x5 test system is within +/- 0.004 mm's. It helps. I couldn't believe how out of spec some of my cameras were out of the factory.

In my limited case I really can't tell the difference between my MF and LF images on film. It takes at least 20x for me to even _begin_ to tell a difference. Enlarged print? That's another matter and LF wins the day due in large part to surface area.

[paulr]

"Film is the resolution limiting factor. Period"

This makes no sense, especially in large format or in black and white. Go to the Kodak website and download MTF charts for tmax films. Their mtf response, into the high frequencies, goes way beyond what any photographic lens can approach. A summary of Tmax 100: MTF 100% at 50lp/mm; MTF 70% at 100lp/mm; MTF 50% at 120lp/mm.

In fact, the idea of limiting factors is conceptually incorrect. We don't work with equipment and materials that act as low-pass filters (cutting off resolution past a certain point). They act as contrast softeners, exerting greater influence as frequencies get higher. It's never a weakest-link-in-the-chain proposition. Every link in the chain degrades the image somewhat. The total performance of an optical system is determined by multiplying the amount of degradation of every link in the chain. If we are looking for a resolution limit, it would be the point where contrast of fine detail becomes indistinguishable from the contrast of the noise (including grain). But how high this frequency is tells us next to nothing about the perceived quality of an image. For that we need to look at the contrast of image detail at key frequencies on the print, which are significantly lower than the highest frequencies our eyes are capable of detecting.

"Regarding lenses, I see no difference on film between the various formats."

My guess is that you're comparing using resolution numbers, which are a contrivance that tell little about how a lens performs in real life. If you compare MTF charts of small, medium, and large format optics, you will see a significant increase in performance as the format size gets smaller. It's just much, much easier to design a lens for a 40mm image circle than for a 150mm image circle. In the end it doesn't matter much ... a 30% loss in modulation is insignificant compared with a 300% reduction in enlargement factor.

To see for yourself, go to the Schneider site and compare the Apo Symmar L series with their digital (medium format) series. You can also go to the Zeiss site and compare hasselblad lenses to contax lenses. Same phenomenon in both cases. It's NOT that the companies are trying less hard with the larger formats. They're doing the best they can within the design constraints of each format.

In the larger scheme of things, I suspect that film flatness and diffraction make a bigger difference than lens performance, but it's all a factor.

[Mike Butler]

I agree with Christopher.

I'll never forget the first time I saw an 8x10 transparency of a food shot on the light table when I started in magazine editorial 18 years ago..

But improvements in color emulsions (grain, contrast, saturation, sharpness) probably did more than anything to displace large format in favor of medium format. The quality of the film simply made the smaller film size good enough for 4-color separation (unless you needed the creative perspective control of LF, of course.)

Viewing distance is another factor in sharpness. That art director looking at the 8x10 through a loupe might have been akin to viewing a billboard from a couple feet away.

Subject matter can also affect the perception of sharpness. Even the highest-resolving films might look mushy if the subject doesn't offer a lot of texture or fine detail.

Best,

[Herb Cunningham]

I gotta get in this.
When i was a part time pro, in college, i used to shoot weddings with a speed graphic and #2 flashbulbs. That was with the stock graphic lens, I think a 150 f 4.5. Never any complaints about sharpness.

I also did the occasional portrait or bride's shots with a dagor, I think was 240mm, anyway it was all the bellows could do to get a good focus, I had to lock down the rail really tight so it would not move due to bellows tension.

I ran across an 8x10 from that era, the 1950's, that was enlarged on a condenser besler, a month ago. The print is so sharp that you can see the threads in the knots on the bride's veil. Any sharper than that, who needs it for ordinary photo work, i.e non scientific or military.

Many times I see people who know little about photography and less about art looking at an 8x10 or god help us a 16x20 at a distance of a few inches. Does not make sense. I think the human eye can only resolve ten or so lines per mm right?

[paulr]

"Many times I see people who know little about photography and less about art looking at an 8x10 or god help us a 16x20 at a distance of a few inches. Does not make sense. I think the human eye can only resolve ten or so lines per mm right?"

Just remember that sharpness and maximum resolution have almost nothing to do with each other. You could look at two prints, one that resolves 30 lp/mm (measured with a microscope) and another that resolves only 5 lp/mm, and the lower resolution one might look much sharper, if it preserves more contrast in the 1 to 5 lp/mm range.

It's also possible for negative A to look sharper than negative B in a contact print, but for B to look sharper than A in a 5X enlargement.

I'd also add that some people like to examine a print from a few inches away. Not just out of technical geekery, but out of fascination with
the sense of detail that goes on for ever. Makes me feel like a voyeur.

[Oren Grad]

Many times I see people who know little about photography and less about art looking at an 8x10 or god help us a 16x20 at a distance of a few inches. Does not make sense.

Remember that people have different purposes for their pictures. With rare exceptions, I don't make prints to hang on a wall. I make them to hold in my hand, and enjoy looking at subtleties in the way the image is rendered and grooving on, as Paulr put it, "the sense of detail that goes on for ever". "Good enough for normal viewing distances" isn't good enough for my normal viewing distances.

I think the human eye can only resolve ten or so lines per mm right?

The appearance of fine detail in a print is affected by MTF at frequencies quite a bit higher than 10 lp/mm. Even if you can't resolve separate lines, the information still makes a difference in the appearance of edges and of fine detail.

[Mark Sawyer]

Comparing 35mm to, say, 8x10, I would think the increased distance from the lens to the film would play a factor; less than 2" on 35mm turns into 12" on 8x10.

I doubt the quality of glass in 35mm lenses is better than in large format. If anything, the lower production numbers and increased cost of lf lenses, along with the more demanding nature of the people using them, would lead manufacturers to put their best glass into lf lenses.

I don't think the film base would have much to do with it, either; it's not between the emulsions of the film and paper, (or in the film/loupe/eye circuit). It might cause a slight effect of diffusion in illumination, like between prints from a diffusion enlarger compared to a condenser enlarger, but to a much lesser degree.

Diffraction, too, probably plays a part at small apertures...

As a b/w person, I prefer lf for the detail, but also for the tonal scale, control, and the working process.

[John_4185]

Grain can enhance perceived sharpness.

[Charles Hohenstein]

I understand that Sinar makes a sheet film holder that holds one sheet instead of two, and which is designed with a pressure plate to improve film flatness. I believe they also make a film holder where the film actually adheres to the holder. Has anyone actually tried either of these?

[paulr]

"The appearance of fine detail in a print is affected by MTF at frequencies quite a bit higher than 10 lp/mm. Even if you can't resolve separate lines, the information still makes a difference in the appearance of edges and of fine detail."

This is an interesting question. It's been studied quite a bit by perceptual physiologists and psychologists. There's no short answer, since the optical qualities of people's eyes differ, and since our vision is very sensitive to contrast. There's a big difference between the maximum resolution we can see in a backlit, etched bar target illuminated at ideal contrast vs. normal detail in a photograph.

Here are some numbers that may be interesting ... all of this presumes looking at something 10 inches away. The absolute maximum resolvable frequency of the human eye, assuming perfect optics and ideal contrast conditions is 14 lp/mm. A more typical maximum is 11 lp/mm. The maximum most people can see in high contrast image detail in a photograph is about 7 lp/mm. The maximum most people can see in moderate contrast image detail is around 5lp/mm.

The detail that makes a print look reasonably sharp is in the 1 lp/mm range. The detail that makes a print look very detailed is in the 5 lp/mm range. If you have excellent contrast in the 5 lp/mm range, the print will look very much like a contact print, regardless of the presence of detail at higher frequencies. Detail at frequenies higher than 10 lp/mm is completely irrelevent, however, in the digital world higher resolutions can help with issues unrelated to detail (aliasing, etc.).

"The appearance of fine detail in a print is affected by MTF at frequencies quite a bit higher than 10 lp/mm. Even if you can't resolve separate lines, the information still makes a difference in the appearance of edges and of fine detail"

this actually is not supported by any of the research that I've seen, or by any of my own experiments.

[Oren Grad]

Paulr, what you're calling "resolution" isn't anywhere near the whole story about what the human visual system can discriminate.

The eye can perceive differences between a bar target (square wave) and a sine wave target up close to the limit of perceived "resolution", indicating that somehow the perceptual system is processing some of the higher harmonics that make the bar target "square".

Beyond that, there's a huge literature about what's called "vernier acuity", as distinct from "grating acuity" or "resolution acuity". A simple explanation and visual representation of the difference are here:

http://www.pc.ibm.com/ww/healthycomputing/vdt13eyee.html

Note the observation that vernier acuity is about ten times greater than minimum separable acuity. That may be a bit optimistic; but a quick scan of the PubMed database unearthed the following in a recent paper:

Vernier acuity, the psychophysical threshold for discriminating a spatial offset between two vertical lines, is one of the most sensitive measures of visual discrimination (10, 11). The vernier
acuity of human subjects can be as small as 6 seconds of arc (hereafter, sec arc) (10). Vernier acuity is considered hyperacuity because it is five times finer than resolution acuity (~30 sec arc, roughly the same as the foveal cone spacing; ref. 12). A similar relative level of hyperacuity in vernier tasks has been measured behaviorally in both cats (~1– 2 min arc) (13, 14) and monkeys (~10 sec arc) (15, 16). Because of the high level of psychophysical vernier acuity compared with the size of the smallest receptive fields (RFs), it is likely that information must
be integrated from multiple neurons to achieve perceptual discriminations.

Proc Natl Acad Sci U S A. 2005 Mar 1;102(9):3507-12.
www.pnas.org/cgi/reprint/102/9/3507 (http://www.pnas.org/cgi/reprint/102/9/3507)

There are plenty more similar references where this one came from.

[Oren Grad]

Sorry, I meant to make all of the hyperlinks "live":

www.pc.ibm.com/ww/healthycomputing/vdt13eyee.html (http://www.pc.ibm.com/ww/healthycomputing/vdt13eyee.html )

[Oren Grad]

If you have excellent contrast in the 5 lp/mm range, the print will look very much like a contact print, regardless of the presence of detail at higher frequencies

"Very much like" is not the same thing as "indistinguishable from".

OK, enough for now...

...contact-print-junkie Oren

[Ed K.]

Just casting a vote, chiming in, the people who know better

than I do have already said it all -

Sometimes it all just comes down to magnification, whether it

is depth of focus, depth of field or how sharp the print looks.

When people figure out a near and far depth for tabletop, it is

always based on the accepted circle of confusion, which assumes

the final print size. So many compromises, so many variables

in day-to-day shooting - a little softer overall, or too shallow

focused area?

I've compared my results from Canon digitals, Fuji MF cameras

with fantastic lenses, 4x5 and 8x10. The Canon ones are filled

with all sorts of problems ( distortion, lack of edge sharpness, etc.)

however from the Fuji MF lenses through Fuji LF lenses on

8x10 - all have amazing sharpness when I'm not pushing the

envelope by shooting at f64 or f8.

I have 8x10's that you can count screws on a building flashing

at a distance of 150 feet. The trouble with the 8x10s is that

one needs a huge print to appreciate just how much detail

can be there. The Fuji 6x8 chromes just pop off the light

table - amazing - yet, similar shots with 8x10 seem to

hold gobs more detail.

The MF advantage seems to be that for reasonable

enlargements, there is less magnification in the shot for

tabletop or portrait work, so depth of field seems to be

more, as long as it's a moderate sized print. And MF is

easy to focus and hold still by comparison to LF too.

Sure, in a resolution test, people have shown than

MF lenses can resolve more - yet with less magnification, the

8x10 still appears to pull it all in, yet have smoothness and

lack of grain.

Let's see a 10 foot wide blowup of the

medium format vs. the 8x10 and then see how well

they hold up. The concert of all the factors will play out.

As a side note - I don't understand why so many people have

film flatness issues in *typical* 8x10 shots ( unless the camera

is pointed down or something ). Afterall, to "correct" distortions

or induce them, don't most shooters swing or tilt their backs

at times? I guess it depends on which lens and other things

( like magnification!). I mostly use Grafmatic backs for 4x5,

and I can't seem to find any issues with flatness - sharp edge

to edge, all across. Are there a bunch of bad film holders

out there? I have noticed that two cameras I bought had to

have thier GG / film plane height altered to work right, however

after that, all was well.

I think the person who wanted the reshoot was either using

a crummy loupe, or perhaps looking at some stuff that was

stopped way down for other considerations. I always hand

people a decent ( Schneider in this case ) loupe, and a large

one at that - it helps them wander around in there better.

Maybe she was looking through the diffused side of the protective

sleeve!

On the other hand, if the small or MF photo got the decisive

moment, in the right place, or was produced at a cost someone

could afford yet still fit the job - that's another discussion!

[Ralph]

.

Um, no, it's not about "a crummy loupe." Let's reread the original post.

As the original poster said, "The girl had a point. Those sheets of color did not seem to my eye as “sharp” PER SQUARE INCH as 35mm and 120 roll film. Especially under a loupe."

So forget about enlargement factors: What the woman saw through a (1x1-inch?) loupe has nothing to do with enlargement factors, which we all agree gives an edge to 8x10 at a given *print size* (but not at an equivalent *enlargement factor,* e.g., 16x for 35mm compared to 16x for 8x10).

We can argue about why it is true (film flatness, film thickness, lens quality, etc.), but the fact remains: PER SQUARE INCH (i.e., enlargement issues aside), an 8x10 transparency will not match a square inch of a sharp 35mm transparency, period.

Or does anybody here really think that putting a loupe to an 8x10 chrome will show a 1x1-inch area that's as sharp as putting the same loupe to a 35mm slide? If so, I suspect I'm not the only one who'd like to hear more about your equipment and methods!

[John_4185]

Interesting and new material here!

But really - the art person with the loupe just got the thing. She probably doesn't even know how to use it or what to look for. The loupe might be a real junker, too. (Could have made her day by screaming "Don't touch the film!". Oh God! We have to reshoot!") As long as the photographer got through to her and her company can write a check that resolves, hopefully, many digits to the left of the decimal point, it's all okay.

And what kinda boyfriend buys his lady a loupe? What's that all about?

[Jorge Gasteazoro]

Could it possibly that the 8x10 transparency was actually not sharp. We are all assuming that because this was taken for a client that the best technique was used, but then there are things like a misaligned ground glass, a warped film holder, etc, etc. That have ot been taken into account. I was curious, so I looked at one of my 8x10 negs taken with a Sironar N and one of my MF negs taken with a hasselblad and while the hassleblad negative has a slight edge, the 8x10 negative under a 4x loupe looks very sharp.

So I took scans of roughly the same area in both negatives, about 1 sq inch.

8x10

http://www.yesalbum.com/v001/jorge0658/Ebay/1sq810.jpg

MF

http://www.yesalbum.com/v001/jorge0658/Ebay/1sqmf.jpg

I dont have a very good scanner since I only use it to proof negatives, but given that both images were taken with the same scanner, the errors from it apply to both images.

[John_4185]

http://elearning.winona.edu/staff_o/jjs/404.gif

Something's wrong, Jorge.

[Jorge Gasteazoro]

8x10

http://www.yesalbum.com/v001/jorge0658/Ebay/1sq810.jpg

MF

http://www.yesalbum.com/v001/jorge0658/Ebay/1sqmf.jpg

[J. P. Mose]

"The major, if not singular, quality which sheet film brings to the party is a remarkable ability to capture exquisitely fine detail. One often hears law enforcement people on the news lament the poor quality of digital surveillance pictures (which can’t be clearly enlarged) in bank robberies. "

Maybe why law enforcement still uses film, along with the fact that film can't be altered to change the facts.

[Dan Fromm]

Folks, reciting textbook results is alwaysamusing but in this case reports on shootouts would be more informative. So is posting images of different subjects shot at unspecified apertures with unspecified lenses on unspecified emulsions, but same/same/comparable/same would be more informative.

Since the original poster asked for a comparison of sheet film and roll film, has anyone here shot the same subject with the same lens with nominally the same emulsion at the same aperture on sheet film and on roll film? If so, please tell us how the results differed.

The thread then drifted to a series of rants about whether lenses made to cover LF, whatever that means, are sharper than lenses made to cover just 35 mm still. I reported one carefully done comparison (same subject, same emulsion, same apertures, same magnifications) done with roughly comparable lenses, in which the LF lens won. Can anyone else report similar shootouts?

Let's have more light, less heat, and fewer irrelevancies.

Cheers,

Dan

[Ralph]

Dan, I agree that flatbed scans aren't going to show very much. The only real test would be scanning a 35mm slide in a standard 4000dpi film scanner and cutting out a 24x36 piece from a large format transparency and scanning it in the same scanner. I don't have the capability to do that and even if I did I'm sure someone would take issue with the setup, film, or lens I used.

But your claim is still surprising to me, because while 35mm and MF lenses routinely resolve 90+ lp/mm (Christopher Perez's Mamiya 80mm resolved 120) I've never seen tests showing that LF lenses resolve more than 70 or 80. Christopher tested dozens of LF lenses, IIRC, and maybe he only tested mediocre lenses but few tested above 60 and only one or two resolved above 70).

http://www.hevanet.com/cperez/testing.html

It is so well-known that smaller format lenses almost always outresolve larger format lenses that it usually goes without saying, but if you're right and common wisdom is wrong -- if you can show proof of what you're saying -- I think it would really shake up a lot of DSLR/35 and MF discussion forums! (I'm kind of hoping I'm the one who's wrong, because if I can find a lens that "covers" 8x10 and resolves 80+ lp/mm on film, I'll have to figure out a way to buy it. . . : )

[John_4185]

Thank you for the pics, Jorge. Dan Fromm, I feel your pain and appreciate your skepticism regarding adequate performance over abstract metrics and assumptions regarding the Latest, Greatest (and most expensive).

Scanners are so problematic. I have a cheap Epson 3200 and don't plan to upgrade unless it breaks (and it is behaving badly.) It seems to suffice for web work.

FWIW, another data point (or not) see this: elearning.winona.edu/staff_o/jjs/f/ (http://elearning.winona.edu/staff_o/jjs/f/)

[Stan. Laurenson-Batten]

John.
I think it relevant to your question and to the KISS principle.

When I took up LF it was suggested that to obtain and maintain the correct overall film plane the surface of the dark slide should be double-sided taped. A method I have used at times, but which I am not fully convinced as to its merits. For me it just gives that little extra confidence in the end product.

[Christopher Perez]

I'm happy that people have pulled reality back into this conversation. So I'll refrain from replying regarding the validity of USAF test charts vs MTF vs aerial USAF chart inspections through the lens through an eyepiece. :-)

There was a question if someone had compared MF/LF film resolutions. I have. I see no difference between the native resolution of the various format's film. I have not checked 35mm film resolution. But I assume (and this might be dangerous, particularly around trollops wielding loupes :-) that 35mm film resolution is no different than MF or LF film.

[Jorge Gasteazoro]

The point I was trying to make was that I dont use a very rigourous technique. I focus on the ground glass, no loupe, and if it looks good in the GG it will be good enough for contact printing, even so the negative is very sharp, I cant see how transparency film would be any different, which leads me to beleive perhaps there was a problem with the transparency.

Having said that, I do have all the information about the lenses, aperture and exposure to take both images, but this is useless information, the end result we are looking for is two sharp images to compare.

[Dan Fromm]

Ralph commented, with sensible skepticism, "But your claim is still surprising to me, because while 35mm and MF lenses routinely resolve 90+ lp/mm (Christopher Perez's Mamiya 80mm resolved 120) I've never seen tests showing that LF lenses resolve more than 70 or 80. "

Ralph, you're right to be skeptical. Also a little wrong, I fear.

I picked the 200/4 MicroNikkor AIS precisely because it is not that great a lens. Modern Photography published a test of the AI version (same optics) in their 5/81 issue. At 1:49, the best resolution measured was at f/11, 49 lpmm center @ 49% contrast, 44 lpmm edge @ 29% contrast. It doesn't really cover 35 mm at infinity that well. Nor, in my experience, close up.

Many, not all, lenses for 35 mm that MP tested around the same time did much better than the 200/4 MicroNikkor. I still use my old 200 MicroNikkor. It is good enough, very useful, and a lot easier to use on a Nikon than the GRII.

Now, I regard the 55/2.8 MicroNikkor AI/AIS as a great lens. But the best MP got for it, test published 11/80, at 1:49 was 78/55 resolution 58/55 contrast at f/5.6; at 1:2, 64/54 resolution, contrast not reported, at f/5.6 and f/8. Not quite the 90+ that you believe in.

Ages ago MP published a piece on whether 100+ lp/mm was attainable with 35 mm still. Their answer was a carefully qualified yes. Getting that much resolution required a very good lens, high resolution film, more steadiness than most of us ever manage, and very careful focusing. As a practical matter, resolution that high is a fantasy, especially with ISO 100 and faster color films.

I picked the 210/9 GRII because it is the best lens I have at that focal length and because it is pretty good too. And since I did the shootout with a Nikon, there were no coverage problems with it.

We should all remember that most blanket statements are false, at least at the edges. There are great LF lenses, mediocre and worse ones for 35 mm still. I don't know how great lenses for LF compare with great lenses for 35 mm still. I've never asked that question m'self. But I know at first hand that pretty damn good lenses for LF can beat middling lenses for smaller formats.

Cheers,

[John_4185]

[b]dan[/b[ We should all remember that most blanket statements are false...

Including that one. :)

elearning.winona.edu/staff_o/jjs/f/rez1.html (http://elearning.winona.edu/staff_o/jjs/f/rez1.html)

[paulr]

Oren, I haven't seen any literature correlating verneer accuity with a sense of sharpness or detail perception. Vernier acuity has to do with our ability to perceive that two segments of a line are offset from each other. Our verneer accuity does not allow us to distinguish detail beyond our MTF limits, but it does allow us to be annoyed by aliasing effects. In digital printing, it comes up when a print depicts a line that is just a bit off of horizontal or vertical. The stairstepping, even at intervals of 720 pixels per inch (a frequency capable of resolving 10 to 14 lp/mm), can be visible. The reason it ususally isn't is that the print driver employs anti-aliasing features, and is actually creating those pixels with dots deposited at two to four times the pixel resolution.

Our MTF limits also say nothing about the size of the smallest individual detail that we can perceive. With enough contrast (as with a fine slit in an opaque material, backlit) we would have little trouble seeing a line that's a 1000th of a milimeter wide. But we wouldn't be "resolving" it ... we'd just be detecting the light that is an artifact of that slit. If brightness were adjusted to compensate, we would not be able to distinguish this slit from one that's ten times as wide, or from a pair of similar slits that are within a few widths of each other. Which is why the visual effect of such a fine line can be exactly duplicated with much lower resolution.

Here's a test that I propose to anyone curious/bored enough to try it out. Find a print of yours that has exquisitely well defined fine detail in some part of it. Then get as good a scan as you can from that section of the negative. Zoom in with photoshop, with the rulers set to "pixels" Do whatever sharpening you need to do clarify the detail. Then measure the finest features you were able to detect on the print, and calculate actual size based on your scan resolution. My guess is you'll be surprised by how coarse it actually is. We hear a lot of impressive numbers thrown around by people who do resolution tests of lens (or who hang out a lot in Leica forums) ... so numbers like 100 lp/mm start to sound normal to us. It's easy to forget that 10 lp/mm on a print is actually incredibly fine detail. If you think you're used to seeing detail in this range, my guess is that you've been brainwashed a bit by unrealistic numbers being thrown your way on the net.

[paulr]

"Or does anybody here really think that putting a loupe to an 8x10 chrome will show a 1x1-inch area that's as sharp as putting the SAME loupe to a 35mm slide?"

For the purposes of the original question, yes, it's the same. John was asking why the image on the big film looked soft. Theoretically, if the optics could produce the same MTF at the film plane, and if the film had the same MTF qualities from one format to the other, and if all other variables were the same, then you'd expect to see the same quality on film with the same loupe. He's asking why they were different.

We've gone off on a lot of tangents, but have come up with a few big reasons: diffraction (the big lens gets stopped down more), lens design (a lot of compromises get made to get that lens to cover the big negatives), and film flatness (good luck with 8x10).

As everyone pointed out, and as the art director finally got convinced, all of this gets trumped by the much smaller enlargement factor. But it seem clear that sadly, you don't actually get a 7-times sharper and more detailed image by moving from the 35 to the 8x10. There are diminishing returns as you get bigger and bigger.

[paulr]

3 excellent normal lenses, 3 formats:

leica 50mm f2.0: http://www.photodo.com/prod/lens/detail/LeSummicron-M50_20-259.shtml

schneider xenotar 80mm f2.8 (for rollei): http://www.photodo.com/prod/lens/detail/RoSchneiderXenotar80-721.shtml

schneider apo symmar L 150mm f5.6: http://www.schneideroptics.com/photography/large_format_lenses/apo-symmar-L/pdf/ApoSymmarL_56_150.pdf (notice that this mtf is given at 5, 10, and 20 lp/mm, as is typical with large format, but half the frequencies used for small and medium)

the biggest drop off in performance is between medium and large format, which corresponds with the biggest increase in angle-of-coverage requirement.

[Oren Grad]

Paulr, detail resolution per se is not really the fundamental issue for me. What I'm interested in is what it is that makes a silver contact print look different from a projection print, or from an inkjet print, and also in what accounts for the capacity of prints to render exceedingly subtle differences in the optical character of different lenses. I'm extremely skeptical that these subtleties can be fully accounted for by an MTF that's truncated at 10 lp/mm, and the literature supports the notion that information at higher frequencies can have perceptual effects, even if they are manifested as something other than recognition of spatial detail. Your observations about aliasing are not inconsistent with that.

[John_4185]

someone: http://www.photodo.com/

Please tell me how relevant photodo's information is to the rest of us? I don't burn images onto my retina with aerial focusing instruments. How can their abstract tests be any good?

[paulr]

photodo uses a method of extrapolating mtf data that's considered in the industry to be reasonably accurate. which makes it much more useful than any resolution test chart numbers in predicting how sharp an actual photograph will look.

it takes some work to learn to interpret the data, but once you do, it will demystify a lot of the pseudoscience that's floating around, and will probably make all these sharpness/resolution ideas make a lot more sense to you.

[paulr]

"I'm extremely skeptical that these subtleties can be fully accounted for by an MTF that's truncated at 10 lp/mm, and the literature supports the notion that information at higher frequencies can have perceptual effects, even if they are manifested as something other than recognition of spatial detail. Your observations about aliasing are not inconsistent with that."

like other perceptual sciences, the optical ones are young ones. It's certainly plausible that what you're saying could be true. I personally haven't been able to support any such ideas in my own informal tests (and I'm not trying to suggest that this proves anything, but it's suggestive to me). What I find, which is corroborated by all the real science I've looked at is that those high frequencies (above 10 lp/mm), if they're detectable at all, are much less important to the subjective quality of the print than the frequencies that are much coarser.

In my attempts to get a contact print kind of quality out of digital enlargements, the magical frequency has been 5 lp/mm. Accentuating this frequency will actually destroy some information at higher frequencies (whether done digitally, or by traditional means like a developer than encourages edge effects or coarse grain). But it sure makes a sharp, detailed, tactile looking print. I'm reminded of a friend's incredible looking 8x10 contact prints. he uses gigantic old proecess lenses (zeiss apo tessars and kodak copying ektnons). His negatives are not very detailed when looked at with a loupe; i suspect enlargements would not be great. But they're magical at actual size. I think what's going on here is emphasis of just the right frequencies, rather than rendering of microscopic ones.
'

[Oren Grad]

This discussion is necessarily theoretical - it's very, very difficult for an amateur to carry out an investigation that can say anything definitive about perceptual effects of those spatial frequencies in pictorial work. It's very difficult to create pictorial test standards with specified MTF properties that can be verified outside of the experimental measurement system itself, and probably impossible to find lenses with specified MTFs that are identical except for the domain of comparative interest.

So it's sort of academic, and what I do for my own snapshooting is driven by what I see in a purely qualitative and subjective sense. It's possible that we have a different sense of what "contact print quality" means. I'm not a huge fan of exaggerated edge effects - never could get excited about Rodinal - or of what usually passes for a "sharp, detailed, tactile looking print". One of the reasons I dislike BPF200 so strongly is that, at least in my hands, it seemed especially prone to that sort of behavior. Nor have I been thrilled with the tonal character of those process lenses I know best, the G-Clarons - in many circumstances they're a bit hard-edged and unsubtle for my taste. But this is all just a matter of personal taste.

Perhaps someday I'll have a chance to see some of your work, so that I can calibrate my own perceptions against yours.

[John_4185]

Okay, a little experiment. Sorry, no ramblings of MTF, CoC, BFD, or LSMFT. It's just a picture.

I put up an image. If you click on the lower left corner, you will see an enlarged portion. Click on that new image and it will bring up another of the same image enlarged and marked off in one millimeter sections.

The lower-left corner was chosen because it's usually the least sharp area of a wide-angle lens.

Now you are (if I got the metrics right) looking at one millimeter squares of film (degraded through the poor scanner, etc..) at the very lower left corner of the image. You can see detail.

Click around: elearning.winona.edu/staff_o/jjs/f (http://elearning.winona.edu/staff_o/jjs/f)

It's no great shakes of a picture. If from time to time I get better results, then cool. If I do not, then I ain't gonna take up the photodo bible for salvation.

[paulr]

jj, i took a quick look at your scan. what's hard about looking at most real world images is that you can only look at detail at the frequency that's present in the scene. for what it's worth, in the area where you marked off milimeters, i saw detail rendered very sharply with strong contrast at around 8 or 9 lp/mm, and hints of detail rendered with much less contrast at about double that. this tells us that your lens/film is capable of this, but it might be capable of more ... we don't know if the detail being rendered at low contrast was low contrast to begin with, or if that contrast was lost in translation. subjectively, i'd think this negative would make a very sharp print, even though there isn't a lot of significant high frequency detail.

[John_4185]

Thanks, Paul, that was my point, albeit poorly expressed: there is adequate detail, right out to the very corners. The lens was an aerial mapping lens and should do 80lp/mm wide open, however I don't think I will have many subjects susceptible to exploiting the potential. (A member of this group who has done a lot of lens tests has the same lens without shutter, but it's badly scratched up. Wonder if he will ever try it out. Nudge nudge wink wink, CP.)

However, regardless of lens and film, the final print goes through an enlarger and we know the accumulated loss will diminish resolution to a modest figure - perhaps the poor quality of the scanner mimics a similar loss so that it is a good comparison. I really don't know.

BTW, I still haven't found a good deal on an enlarging lens to replace the one I dropped to the concrete floor. No printing until that's taken care of.

[Christopher Perez]

Aerial mapping lens? Well, something happened on the way to the Coliseum. First came a Rollei TLR project, of which too many were collected. The entire darkroom was moved to a new house and it needed to be built in a nice new space (10feet x 20feet). Then came a 7x17 project, which is yielding v.nice results. Shortly thereafter came the 11x14/10x12 format bug. The bug bit hard. And now comes a Paris cemetery Mamiya 7 project which is about to begin this very weekend.

These are the excuses. And they will be repeated in front of a Grand Jury on an as needed basis.

The mapping lens sits quietly waiting for something to happen. On the benchtop above rests a Deardorff 8x10. Strange noises eminate from the basement. They're up to something...

[Dan Fromm]

Chris, just let Biogons be Biogons.

[paulr]

jj, have you made any prints from negs made with lens? contacts? enlargements? i'd be curious to see what the qualities are compared with a regular lens. I must say, your negative looks different from how i'd guess an aerial lens would render things. I was under the impression that aerial film was very high contrast, and the idea was to use lenses optimized for high resolution, at the expense of modulation, and to let the film take care of the accutance. which is a fine idea, since no one cares about pretty tones in mapping. but that biogon looks like it's all about crisp edge definition. did you or your software sharpen that scan much?

[Christopher Perez]

Dan, well said. You're a poet! Your words bring tears to my eyes.

In reality it'll be a 50mm Biogon. It will pay it's respects to Jim Morrison (and many others) in the silvery fall Parisian light of Pere-Lachaise...

[Dan Fromm]

Chris, 50 mm Biogon? Are you sure? AFAIK, ones for formats larger than 35 mm came in 38/4.5, 45/4.5 (very rare), 53/4.5, and 75/4.5.

paulr, by an odd coincidence I shoot a 38 Biogon that I extracted from an AGI F-135 aerial camera. Not a mapping camera. And the same optics, although not shutter, as supplied with the Hasselblad Super Wides. I've shot a number of lenses extracted from aircraft cameras, viz., that 38 Biogon, 1.75"/2.8 Elcan, 4"/2.0 Taylor Hobson, 5"/4 WA Xpres, 12"/4 Taylor Hobson Telephoto, and 14"/5.6 Aviar. The Biogon, Elcan, 4" and 12" Taylor Hobsons are all much better down a couple of stops from wide open, the WA Xpres and Aviar seem best wide open. The WA Xpres and Aviar are uncoated, flary, the others are coated, flare resistant. With the exception of the Elcan, these are all fairly old designs, and even the Elcan may have been designed with little help from a digital computer. So I'm not sure that your ideas of what they should have been optimized for apply to them. Same goes for most, if not all, of the Biogons that flew. Anyway, none of them shoots much differently than "a regular lens."

Regards to both of you,

[Richard Schlesinger]

A very small suggestion for whomever was concerned about tripod steadiness as a factor. Try shooting in a dark room using a strobe for illumination. As I remember, ModenPhotography, some years ago, published some pictures of a light covered with an opaque piece of material with very small holes punched. Even with quite good tripods the holes showed a certain amount of movement/blur. Could this be an additional factor in less-than-perfect resolution/contrast/sharpity or whatever in the photographs under discussion?

And by the way, how many angels are dancing on whose pin?

[Christopher Perez]

Dan, 50mm Biogon design. It's the Mamiya 7 50mm L f/4.5 10 element optic. And these words are not nearly as sweet as those you wrote a couple entries back. I can only hope the photos come out well enough.

[Dan Fromm]

Chris, if they don't come out well the reason will be, um, operator error. Don't know about you, but my gear is, for the most part, better than I am.

Cheers, enjoy your trip,

[John_4185]

Responding to Paulr: As afar as I can tell, the lens has no special high contrast characteristics. If it differs at all from the only other Biogon I know, the SWC's, it's that the mapping lens rear element sits much closer to the film, and is larger than the film it was designed to cover. While in-service we used to play with aerial film (I was on a world-class aerial recon base) and the film had no special contrast characteristic. It was developed in D23 (pretty sure) and _developed_ to contrast.

FWIW, I shot the same picture along side the one in question with the SWC and did a side-by-side but got lambasted for doing so by someone who was, ah, sensitive to comparing LF to MF. He was so pissed, I just took down the pages.

And as for Chris Perez - hey, you got that lens because it's a wreck. Whatever results you get have to be compared to another of the same. I have three more. We will do that comparison over some good coffee at your place, say 2030 (the year, not military clock time.) Hope that's enough lead time.

Dan Fromm: "let Biogons be Biogons". LOL! You made my day.