How does a grainy large format photo compare to a finely grained 35mm?

[pentaxuser]

It seems to me that the OP was asking a very specific question out of academic curiosity. If our aim each time a question is asked is to respond with answers that we hope will answer the questioner then we need to know if we have succeeded.

So Trondsi, have we answered your question and satisfied your curiosity? Thanks

pentaxuser

 

[alentine]

Making 5x4 print from the 35mm SUPER system(enlarged 3.76 times) for fair comparison, the print will only retain 64lppmm, which is equal to what a modest LF system can achieve.

Before anybody wonder, how can the 35mm CMS20 film that resolved 240lppmm(with SUPER lens), enlarged 3.76 times, to make 5x4 print, for comparison with 5x4 triX/HP5 film ?
Very valid question that I confess it was not covered in my previous post!
Yes, the film should go through enlarging machine, before considering the format factor(3.76) that brings its resolution from 240lppmm to 64lppmm.
If I assumed that the enlarging machine, is actually enlarger lens!
That enlarger lens should be SUPER perfect lens, capable of resolving just a little above 9999lppmm(to transmit full 240lppmm), before accounting for format factor 3.76x. Yes, something around 10,000lppmm.
But, hopefully, any lens that can transfer 2500lppmm or above accurately, can do the job well.
This step, will not throw away 35mm at its best from LF, but also 6x7 Medium Format. More with real example later.
If you have only a decent enlarger lens that can only transfer 400lppmm, then you will lose around 40lppmm immediately, and the combined system will retain only 206lppmm. After applying format factor of 3.76, the 5x4 print from 35mm CMS20, will show only 55lppmm.
I know the numbers above are in the zone of impossible, and just theoretical.
But, fortunately, can be understood and even interpreted. It places every format in its correct real level.
It's the same process that bring in comparison 35mm CMS20 grain size, with grain size of a popular 5x4 films like tri x/HP5, considering all other factors equal in each comparison.
That led, if there is still any doubt about grain size, to introduce Medium Format CMS20, into the comparison, which is definitely has finer grain than most of LF films(other factors equal and as I understand).

 

[alentine]

Before considering real examples of Medium Format sharpness compared to LF, let me make it clear that 35mm CMS20 is the only example I know that could beat LF popular grainy films, in grain size. And only, in grain size.
.
Back with some real example from Medium Format about sharpness.
http://www.hevanet.com/cperez/MF_testing.html
The best system(lens + tmx100) above(link) can provide 120lppmm. It's 6x7 MF Mamiya 7 taking lens + tmx100 film.
1/Rs^2 = 1/Rf^2 + 1/Rl^2
Solving the equation, by distributing resolution among lens and film equally(and theoretically, for easier calculations), each should resolve about 170lppmm, to bring the system resolution to 120lppmm.
It's a good real life Medium Format example to start with. It will continue real.
Lets assume that an enlarger lens is used to bring the above real MF tmx100 to 5x4 print(to be compared with 5x4 LF film).
LF/67MF factor of 1.85x(by dividing the diagonals), will be considered later.
Using the above equation, If the enlarger lens can also resolve only 170lppmm, just like tmx100 and best MF camera lens above, the system will still capable of retaining about 98lppmm.
Applying the format factor(1.85x), will result in a 5x4 print that can still show 53lppmm.
A real example that could introduce MF into just the periphery sharpness territory of LF, easily. Which is really great in its own.
Considering MF CMS20 at more realistic level(for pictorial purposes) of resolution, 300lppmm, with the same level of taking and enlarging lenses(170lppmm), will bring the system to only 60lppmm, after applying the format factor.
It's a zone nearer to the middle of real performance of LF lens/film, only if truly the MF CMS20 will provide enough pictorial characters at 300lppmm, and again IF the last number is true.
Thanks.

 

[Nodda Duma]

alentine, you are falling into two traps with your analysis.

1) You are analyzing film grain size as if they are pixels. Film grain is not equivalent to digital pixels which have a defined sampling frequency. Film grain size is a distribution which is centered on a certain size but does not distinctly sample at that corresponding frequency. Early in my optical engineering career I used to try to do the same but it’s simply an incorrect way to analyze a film-based imager.

2) You have to analyze with contrast or MTF: Even if the assumptions were such that you could analyze film as if it were a digital imager with discrete pixels, your analysis is flawed because the spatial frequencies imaged with 35mm vs large format lie on different regions of the film’s MTF curve. This is important because as spatial frequencies increase, the contrast decreases until it reaches 0 at the sampling frequency of the imager. So for CMS20 the contrast is going to be very low at 300 lp/mm. Details in the scene that approach this value will be very low contrast on a 35mm print. The optics come into play as well. Those details will also be softer due to the optical MTF. When shot with a large format camera the sampling frequency for the same scene detail will be much lower (I think at a ratio of the lens focal lengths used but don’t quote me). Since it is a lower spatial frequency as imaged by the large format camera, the contrast of that detail will be much higher due both to the film MTF and sharper due to the optical MTF. Both aspects affect the comparitive resolution, sharpness, micro-contrast, acutance, or whatever other popular concept photographers use to think of the imaging system’s ability to replicate detail.

Obviously comparisons depend on the MTF curves of the specific optics and film, but the relationship will hold for the vast majority of arrangements (except unreasonable comparisons like 30 year old expired 3200 speed sheet film pushed two stops or a large format plano-convex lens or pinhole compared to a Summicron shooting fresh 35mm Tech Pan).

Where the spatial frequencies for a given scene fall on the corresponding MTF curves is the main reason a large format print on grainy film will look “better” than a 35mm print on sharp film.

This is why MTF - often misunderstood - is an important concept for imaging performance analysis...much more important than absolute resolving power.

 

[alentine]

Thanks indeed Nodda.
Great details, which I need.
Will be back after reading your post in detail.
This box is reserved for reply to Nodda.

1) You are analyzing film grain size as if they are pixels. Film grain is not equivalent to digital pixels which have a defined sampling frequency. Film grain size is a distribution which is centered on a certain size but does not distinctly sample at that corresponding frequency. Early in my optical engineering career I used to try to do the same but it’s simply an incorrect way to analyze a film-based imager.

The system resolution equation, has been invented long time before any digital was invented.
1/Rs^2 = 1/Rf^2 + 1/Rl^2
As far as I know, the system resolution equation includes square denominators, which is far from being digital.
I can realize that any film has different sizes of grain, but once a given film is capable of resolving a certain number of LPPMMs, and proved that in reality after development, it does so with all of it's structural materials, including finer grains(mainly) and bigger ones.
Films that has been tested for LPPMM and a certain number of resolution has been given, are representing system resolution, which was attained by Real Actual Practical process, not by just calculations.
Do not know why you assumed that my calculations are digitally pertaining more than film?
.

your analysis is flawed because the spatial frequencies imaged with 35mm vs large format lie on different regions of the film’s MTF curve. This is important because as spatial frequencies increase, the contrast decreases until it reaches 0 at the sampling frequency of the imager. So for CMS20 the contrast is going to be very low at 300 lp/mm. Details in the scene that approach this value will be very low contrast on a 35mm print. The optics come into play as well. Those details will also be softer due to the optical MTF. When shot with a large format camera the sampling frequency for the same scene detail will be much lower (I think at a ratio of the lens focal lengths used but don’t quote me). Since it is a lower spatial frequency as imaged by the large format camera, the contrast of that detail will be much higher due both to the film MTF and sharper due to the optical MTF

The quote above has enlighten me.
Thanks Nodda.
One point to be added here.
The LPPMM performance of each format lenses are not the same also. Lenses MTF is greatly variable among format sizes, also.
Please let 35mm to be out of any further comparison, MF is still valid to be compared with LF in this context.
Comparing best with the best, LF vs MF.
While a recent 5x4 LF APO lens can give 60% MTF(center) at spatial frequency of only "20" cycles/mm, an equivalent focal length MF lens produced 67% MTF(center) at frequency of "40" cycles/mm. It's double plus extra performance.
Review MTF of Schneider APO-Symmar L 210/5.6, and Zeiss Hasselblad Planar CF 100/3.5 .
Both lenses will show about the same field of view, but at roughly double size image on film, which could be compensated for by the great(double) difference in MTF performance.
At this specific example, if tmx100(or CMS20) was used in MF and on the other hand a trix/HP5 was used in LF, I think MF will give hard time to LF(if not out resolve it).
No wonder, I've seen MF prints that can be compared(NOT clearly exceeding) in sharpness, to 5x4LF prints at sizes up to 60x50 cm.
I know comparing MTF from different vendors, is dangerous. But, what to do if no other comparison method available, and both lenses from the best German manufacturer? I think, there is still some validity.

 

[alentine]

Ok, just awhile found the following thread/post.
The quote is about 35mm CMS20 resolution with Zeiss lens(System Resolution):

Adox CMS 20 II, Spur Modular UR New or Adotech II developer: 240 - 260 Lp/mm.

Post number: 19
It represents a Real Life example of 35mm film system, that hit 240lppmm.
It's not any more hypothetical, the number, in its own right.
If system resolution equation(previous posts) is applied, the resulted evenly distributed resolution is 339lppmm for each, the lens as well as for the film.
Which is, again, represents numbers "about" the real life performance from 35mm CMS20 and the used Zeiss lense, each alone.
So, the assumption of 300lppmm for 6x7MF CMS20, is not far away from reality.
Now, looking for the ultimate answer for the biggest question of this thread:
How the photographic qualities of a Real Life number like 240lppmm looks like, in a Real Actual B&W print?

 

[DREW WILEY]

There are a lot more variables involved in real-world photography and printmaking than just this kind of hypothetical number crunching. Lots of people don't even know how to keep the film flat in the enlarger. Fewer still know how to keep film truly flat in a view camera. Even the specific developer protocol with respect to any film can affect perceived acutance. So can the type of paper surface. Often "grainier" large format films yield sharper-looking results than fine-grained films. I work in multiple formats and switch strategies accordingly. If someone simply enjoys number-crunching, that's fine with me. But it won't necessarily give you the kind of answers you are hypothetically seeking, certainly not by itself.

 

[trondsi]

It seems to me that the OP was asking a very specific question out of academic curiosity. If our aim each time a question is asked is to respond with answers that we hope will answer the questioner then we need to know if we have succeeded.

So Trondsi, have we answered your question and satisfied your curiosity? Thanks

pentaxuser

Yes and no. Some of the answers are a bit contradictory, but illuminating nonetheless.

One thing to note to people here in general: although it may have looked like it, I am NOT only talking about grain, but also other differences that would set the formats apart, so that you could still tell which photo was likely taken with a large format camera, despite the film used being grainy. I am curious, because I think I do see some differences that are unrelated to grain, and some that obviously are related to grain. I suppose depth of field is one thing.

EDIT: Forgot to mention that alentine's analysis was very interesting. Large format's ability to be (potentially) grainy but still sharper is a bit intriguing.

 

[Nodda Duma]

There are a lot more variables involved in real-world photography and printmaking than just this kind of hypothetical number crunching. Lots of people don't even know how to keep the film flat in the enlarger. Fewer still know how to keep film truly flat in a view camera. Even the specific developer protocol with respect to any film can affect perceived acutance. So can the type of paper surface. Often "grainier" large format films yield sharper-looking results than fine-grained films. I work in multiple formats and switch strategies accordingly. If someone simply enjoys number-crunching, that's fine with me. But it won't necessarily give you the kind of answers you are hypothetically seeking, certainly not by itself.

Math and models are useless crap if they don’t reflect reality. But make no mistake: Modeling and math are used in engineering and research because they are in fact useful. There is a time and place for prediction of results just like there’s a time and place for trial & error experimentation. The former saves you quite a bit of time, even with time spent verifying the results. The latter gives you practical experience (like anything learned the hard way).

Accurate models — emphasis on the accurate — are far more complex than discussed here, and it would take a book-length post for me to explain all the details required. In the real world, number crunching is essential for designing imaging systems. Just ask Petzval or Mees. Science isn’t a bad word.

Don’t rely on Hollywood’s vision of a nerd with glasses and a labcoat working away in a lab late at night and who never sees the light of day. The reality of R&D and science / engineering is far, far different.

 

[wiltw]

Waaay back, in my high school days, I was on the school newspaper photography staff. We had most guys shooting with 135 format cmaeras loaded with Tri-X rated by Kodak at ASA 400. But when we shot the night football games, we used a Speed Graphic 4x5 camera loaded with Royal-X Pan rated by Kodak at ASA 1250. The larger format allowed much less objectionable grain even with the noticeably grainier Royal-X, compared to to Tri-X.

 

[removed account4]

I am just curious. Say if you took similar photos with 4x5 and 35mm. For the 4x5 you used a grainier (probably ISO 400 or higher, I can't remember seeing 800 in large format lately) film, and for the 35mm you used, perhaps, ISO 100 or finer. Perhaps you need larger differences for them to be more comparable (50 vs 800?). How would the two photos compare? Would the formats vs grain "cancel out"?

hi trondsi
do you have a LF camera and a 35mm camera ?
why don't you burn 2 sheets of film and 2 rolls of film and compare your images ?
if you are going to scan your negatives it might not matter
but with physical prints and depending on the type of enlarger you have
and how you processed your film ( all of it in rodinal or xtol ) ..
you could probably do film and print and developer tests for weeks
its a long rabbit hole to crawl into .. and you would learn a lot about processing,
film and printing ... and comparisions between probably 70 different film and print developers

have fun !
john

 

[pentaxuser]

Thanks for your reply Trondsi. My own conclusion and not based on seeing prints at say 8x10 maximum from a CMS20 negs and from, say HP5+ LF sheets is that I would be hard pressed to pick out the LF prints to a statistically significant level, all other things being equally in terms of correct exposure same DoF etc.

I suspect Joe Public would be hard pressed as well but that's not to say that a photographer with years of experience in all formats could not do so.

pentaxuser

 

[trondsi]

hi trondsi
do you have a LF camera and a 35mm camera ?
why don't you burn 2 sheets of film and 2 rolls of film and compare your images ?
if you are going to scan your negatives it might not matter
but with physical prints and depending on the type of enlarger you have
and how you processed your film ( all of it in rodinal or xtol ) ..
you could probably do film and print and developer tests for weeks
its a long rabbit hole to crawl into .. and you would learn a lot about processing,
film and printing ... and comparisions between probably 70 different film and print developers

have fun !
john

I might do something like this. I usually scan my film though, and my flat bed scanner is not very good (it works best on medium format actually). I just do this as a hobby.

 

[DREW WILEY]

Nodda, I do my homework when buying lenses. You obviously do it when engineering optics. I have many years of hard science in my background, in several fields. I also know how to make far sharper prints than the average darkroom worker (this being just one more tool esthetically, and not necessarily an end unto itself). And I've learned how to get from Point A to B pretty efficiently when designing my own equipment. Watched one of those PBS documenmtaries the other nite which was
related to just how precisely the Egyptian pyramids were built millennia before modern methods of calculation. There's more than one way to skin a cat. I don't attempt to make my own lenses or intricate solid-state circuits. But if I deserve an honorary phD it's in Jerryrigging and Cannibizing equipment and coming up with new ways of doing things more efficiently. Yes, I have my calculator too; and have even concocted customized math models for certain exposure situations where I basically had to write my own Owner's Manual to my own specialized equipment. But on forums like these, it's getting rather predictable for inexperienced people to get quickly lost in the woods by overthinking things. And it reminds of hikers in literal woods stumbling over logs and rocks, and potentially injuring themselves because they spend all their time staring at some stupid GPS device. Our own eyes are actually a far more sophisticated piece of equipment.

 

[removed account4]

I might do something like this. I usually scan my film though, and my flat bed scanner is not very good (it works best on medium format actually). I just do this as a hobby.

sounds good
i just have flatbed too, it works ( and i can't complain )
have fun cause in the end all of this stuff is self dependent
meaning its dove-tailed into your personal way of working.
im guessing there are people alive who can process a roll of tri x or even p3200
in some magical way that works well for them and the enlargements have a smoothnexx to them
and there are others ( like me ) who can process a 4x5 sheet of tmx(100 ) in such a way that it is grainy
and looks like tri x ..
and then the difference between a print and a scan can sometimes be the difference ...
( take notes so you can get whatever effect you like / end up with )
have fun !
john

 

[wiltw]

Based my conclusion on the grain size of other films like Tmax400 and Velvia:
http://www2.optics.rochester.edu/workgroups/cml/opt307/spr04/jidong/
Tmax400 grain size= 2-3 micrometer
Velvia50 grain size= 0.8 micrometer
So, safe assumptions(as far as I understand) of grain size of 3.5 micrometer has been assumed for tri x/HP5 film, and 0.5 micrometer for CMS20.
Considered also, enlarging factor(of 3.76 times) between the 2 format sizes, obtained by dividing diagonal of 5x4 film by the diagonal of 35mm film to compensate for aspect ratios differences.

This started with a bad assumption, based upon the diagonal!
If you shot 135 format with lens FL 48mm (2x format small dimension), and 4x5 with lens FL 165mm (2x format small dimension), both would capture the SAME amount of subject in the small direction of the frame. Then if you fill an 8x10" print with both images, some of the 135 format gets 'cut off' by the frame's length while the entire 4x5 image fits within the 8x10. But the smaller neg needs 8.46x magnification to fill 8" while the larger neg needs only 2.18x, advantage of 3.88:1 to the larger format Nevertheless the end result is same subject content in the two 8x10's. But 8.46x mag of 0.35 micrometer grain vs. 2.18x mag of 0.5 micrometer grain...2.96 micrometer grain vs. 1.09 micrometer grain on the same 8x10 print. One does not need to shoot, develop, and print the two to intuitively KNOW that large format has a BIG ADVANTAGE for grain size alone (1/3 as large in a single direction, but 1/9 as large in two directions on the print). But it is not so simple to step at comparing grain sizes on the print...

Now if we compare what is captured on film, BOTH formats fit the same amount of subject in the frame (under the above circumstances), so if subject occupied 50% of the frame height, on 135mm the subject covers 12mm of the 135 frame while the subject covers 46mm of the 4x5 frame (using Lisco Regal II magazine opening dimension). IOW, in one direction the subject covers 3.83x the amount of film or 14.7x the area of film. So assuming the 0.35 micrometer grain size vs. 0.5 micrometer, in the same amount of film there will be 42% more film grains (of smaller individual size) with the finer grain emulsion in a single direction, or 2x the amount of grains per area (two directions). Something that NO ONE appears to have considered is anything OTHER THAN the discussion of 'grain'. More grains (or color dye clouds) per unit area means that the larger format always has a better ability to capture subtleties of the tonality changes and color changes across the surface of the subject, and that has -- for a verrrry lonnnng time -- been known to be the advantage of larger format over smaller format when shooting with film. Some of that advantage is lost when comparing two different emulsions, such as the assumed use of a grainer emulsion for the larger format camera, but NOT ALL of that benefit of tonality gradations is lost!

 

[RPC]

Perceived tonality improves as format size increases, at least up to a point. Another advantage of larger formats is less visible scratches and dust for a given print size.

 

[Bill Burk]

Another advantage of larger formats is less visible scratches and dust for a given print size.

Scratches and dust are less visible on large format sheet film because of their relatively smaller size.

But.

When you handle the sheets, scratches and dust become less evitable.

 

[Nodda Duma]

Nodda, I do my homework when buying lenses. You obviously do it when engineering optics. I have many years of hard science in my background, in several fields. I also know how to make far sharper prints than the average darkroom worker (this being just one more tool esthetically, and not necessarily an end unto itself). And I've learned how to get from Point A to B pretty efficiently when designing my own equipment. Watched one of those PBS documenmtaries the other nite which was
related to just how precisely the Egyptian pyramids were built millennia before modern methods of calculation. There's more than one way to skin a cat. I don't attempt to make my own lenses or intricate solid-state circuits. But if I deserve an honorary phD it's in Jerryrigging and Cannibizing equipment and coming up with new ways of doing things more efficiently. Yes, I have my calculator too; and have even concocted customized math models for certain exposure situations where I basically had to write my own Owner's Manual to my own specialized equipment. But on forums like these, it's getting rather predictable for inexperienced people to get quickly lost in the woods by overthinking things. And it reminds of hikers in literal woods stumbling over logs and rocks, and potentially injuring themselves because they spend all their time staring at some stupid GPS device. Our own eyes are actually a far more sophisticated piece of equipment.

Too bad I didn’t know you when I lived in Inyokern out near your neck of the woods, Drew, and invite you for a drink of your favorite poison. I think I’ve said it before but we’d probably get along famously. I was a poor country boy fixing farm equipment with duck tape and bailing wire long before I was an engineer. Farm smart came before book smart.

Cheers,
Jason

 

[DREW WILEY]

I lived on the other side of the Range. Yes, I know about bailing wire all too well, first for farm applications, then during my student life which included the eyestrain of three years of microbiology plus invertebrate paleontology, looking at ancient microbes smashed, stretched, and crystallized. I'd love to own one of those classic Zeiss microscopes, which included polarizing, medical, and dark phase units. But just to get to class, I had the ignition of my "budget" VW bug running via a piece of bailing wire and a paper clip! Duct tape was too expensive for me.

 

[alentine]

But 8.46x mag of 0.35 micrometer grain vs.

Thanks indeed wiltw for your interpretation.
It's 3.5 micrometer for trix/Hp5, not 0.35 micrometer, as estimated from other finer grain films measured in my reference. Please review the reference.
Based on that, 35mm CMS20, may show less grain size than 5x4LF grainy films. I do not think there is a problem here.
Subject size on film was considered also, just forget 35mm format, compare MF fine grain high resolution film(like CMS20) with LF grainy low resolution film, for the same area of view.
All that has been mentioned here:

While a recent 5x4 LF APO lens can give 60% MTF(center) at spatial frequency of only "20" cycles/mm, an equivalent focal length MF lens produced 67% MTF(center) at frequency of "40" cycles/mm. It's double plus extra performance.
Review MTF of Schneider APO-Symmar L 210/5.6, and Zeiss Hasselblad Planar CF 100/3.5 .
Both lenses will show about the same field of view, but at roughly double size image on film, which could be compensated for by the great(double) difference in MTF performance.
At this specific example, if tmx100(or CMS20) was used in MF and on the other hand a trix/HP5 was used in LF, I think MF will give hard time to LF(if not out resolve it).
No wonder, I've seen MF prints that can be compared(NOT clearly exceeding) in sharpness, to 5x4LF prints at sizes up to 60x50 cm.

Please read the whole post.
That really deserves to be proved or disproved with real test on prints. Scanning will introduce further factors and will not(I think) provide a better conclusion.

 

[DREW WILEY]

Tests should be done on truly flat film (dimensionally stable sheet film in a vacuum holder) itself worthy of the task, and not on paper. Still, the whole argument so far ignores quite a few important variables, such as the primary reason for view cameras to begin with - focal plane and depth of field corrections not generally possible with smaller gear. If you want to wander into hypotheticals or cost is no object options, well, that can go almost anywhere. By the 1930's there were already international contests to figure out who could put the most number of texts of the entire Bible on a microdot ! I don't even like the late great Tech Pan for general photographic purposes.

 

[Sirius Glass]

A grainy 4"x5" negative focused with a grain focuser will be much finer grain than a 35mm fine grained negative focused with a grain focuser for the same size print.

 

[DREW WILEY]

Just getting acute focus with a loupe and large properly-set groundglass is far easier than on small formats. If your gear is warped or otherwise out of alignment, that's a different story. The most common error with large format (esp 8x10 or larger) is assuming that the film is consistently flat in the holder. But there are ways to correct that. Looking at an 8x10 groundglass through a 7X loupe is like having your nose right up to a six-foot-wide print. With 35mm, it's like examining a mere postcard.
And the current notion of a standard, the web image, is like the latter passed through a cheese grater!

 

[Arklatexian]

A grainy 4"x5" negative focused with a grain focuser will be much finer grain than a 35mm fine grained negative focused with a grain focuser for the same size print.

All this reminds me of an old RollsRoyce story, Someone wrote the factory and asked: I am interested in buying an "X" model of your cars. How many horsepower does the "X" model's engine have? The answer came back with one word: "enough". If my 35mm cameras can take "sharp" 11 x 14 prints, they are sharp "enough" for me. If I make a 4x5 picture and print it to 11 x 14 also and it is sharp also, then it is sharp "enough" for me. I am the only one those formats and lenses have to be sharp "enough" to please..........Regards!