Max resolution film size for large format.

[bluechromis]

I have heard people say that for larger than 4 x 5 negatives, there are diminishing returns on increasing resolution (line pairs visible) in prints because of increased diffraction. Is this true? This question is about enlarged prints where the prints are considerably larger than the negative. The question is NOT about contact printing.

 

[koraks]

diminishing returns on increasing resolution (line pairs visible) in prints because of increased diffraction. Is this true?

Factually wrong. Diffraction is a physics phenomenon and relates to the wavelength of the light and the physical size of the aperture used. The wavelength obviously doesn't change. As you go up in film size, you generally use longer lenses with therefore larger physical apertures for the same angle of view and same f/stop. So diffraction will be less. This will be the case for the recording as well as the printing. Another factor is that for the same print size, you obviously need to enlarge a smaller format much more than a larger format negative, so whatever softness from diffraction is present in the negative will show up earlier (at smaller print sizes) for the smaller negative sizes.

Note furthermore that anything from 4x5" and upwards can be enlarged with excellent results to pretty gigantic sizes, so it's kind of a moot point anyway if you ask me. There is a law of diminishing returns in that sense - there's just very little compelling reason for the vast majority of photographers to go any bigger than 4x5. Typical bottlenecks are formed by the two B's - your Back and your Budget.

I suppose that the 'diffraction' story may have to do with the assumption that lenses for larger formats may not be manufactured to the same strict tolerances as those for smaller formats, resulting in the smaller format lenses outresolving the larger format ones despite diffraction (and not because of it). But that's a wild guess on my part.

 

[Ian C]

Post #2 answers the diffraction question.

What is the largest print you intend to make? The usual range of print sizes using precut paper is 5” x 7”, 8” x 10”, 11” x 14”, 16” x 20”, 20” x 24”, and 30” x 40”.

Within this range of print sizes there is no meaningful advantage using a film larger than 4” x 5”.

If you use a 6 x 7 cm negative and an 80 mm enlarging lens, such an 80 mm f/5.6N EL-Nikkor, its 2X-5X-15X magnification range will make a projection of fine quality up to 33” x 41”, which covers the largest print size given above.

 

[bernard_L]

Factually wrong. Diffraction is a physics phenomenon and relates to the wavelength of the light and the physical size of the aperture used. The wavelength obviously doesn't change. As you go up in film size, you generally use longer lenses with therefore larger physical apertures for the same angle of view and same f/stop. So diffraction will be less.

I suppose that the 'diffraction' story may have to do with the assumption that lenses for larger formats may not be manufactured to the same strict tolerances as those for smaller formats, resulting in the smaller format lenses outresolving the larger format ones despite diffraction (and not because of it). But that's a wild guess on my part.

Beg to disagree. The linear size of the diffraction spot in the film plane (give or take a dimensionless factor of order unity, which is a matter of convention) is :
(f/D) x lambda
Since LF photographers tend to use larger values of (f/D) with increasing film size (see f/64 group), this means that the typical diffraction spot tends to be larger for larger formats. Canceling part or all of the gain in the number of resolution elements ("pixels") from using the larger format.

 

[koraks]

Beg to disagree.

Sure, but I did say:

As you go up in film size, you generally use longer lenses with therefore larger physical apertures for the same angle of view and same f/stop.

That people may stop down further is possible, but it's also not a given.

 

[Paul Howell]

I agree with koraks, with modern films, law of diminishing returns, with 6X9 TMax 100 or Pora 160 negative will provide a top quality print up to at least 20X24. I normally dont print larger than 11X14, the reason I use sheet film is when I'm a zone frame of mind and want to develop each sheet of film for the highlights or what to use movements of my view camera.

 

[bdial]

For me, the only reason to go bigger than 4x5 is to make alt process contacts. I have a 4x5 enlarger, and the largest size I can accommodate for printing is 16x20, and that’s difficult in my DR. I have 5x7 and 8x10 cameras, but no access to enlargers that can use negatives that big.

 

[DREW WILEY]

Logistical issues : With larger formats, like 8x10, an equivalent perspective requires a longer focal length lens than 4x5, hence you are working with a shallower depth of field at comparable aperture, so might need to stop down proportionately to get the same depth of field (f/45 for 8X10 instead of f/22 for 4x5, for example). Of course, the nature of view camera movements and selective composition offsets this to an extent.

The bigger the film, the more risk of it sagging in a sheet film holder and losing some of its acute focus. Solution: use a special adhesive or vacuum 8x10 holder.

How do you intend to print? With inkjet the format distinction makes little difference. But with acute optical printing, I'd rather enlarge an 8x10 original to 30X40 inches than a 4X5 original. Some of this has to do with hue saturation, some to sheer detail, especially in high-detail capacity media like Cibachrome or Fujiflex. There simply something extra there. But I do both.

The general public can't tell the difference between a Cibachrome 30X40 from old Ektachrome 64 4x5 film, shot with an old 210 Symmar S lens, and enlarged with an old Componon S, versus what I do today, shooting with superb Fujinon A lenses in relation to current finer-grained 8x10 film (and 4x5), and enlarged onto Fujiflex using far superior Apo Nikkor f/9 graphics lenses. But I can tell the difference, and it gives me satisfaction.

No way I'm personally going to color print 6x9 beyond 20X24; and even that's dependent on the very sharpest current films like Ektar 100.

 

[halfaman]

4x5" film requires 4 times less enlargement than 35 mm for any final image size. So any optical defects, including aperture diffraction limit, are far less discernible for a viewer in the case of LF. Sometimes we forget that film is not the end but the beggining of the final print or image we are looking for, and it will be contemplated by the two eyes of a human being from a certain distance.

 

[brbo]

Canceling part or all of the gain in the number of resolution elements ("pixels") from using the larger format.

Anyone wants to bring out pen and paper and compute at what aperture a pair of equivalent lenses become diffraction limited on a 100lpmm film for 35mm and 4x5"format and how much further you need to then stop down a large format lens to negate all of the 5x linear size advantage of LF?

But (consider that I'm not much of a LF photographer), don't we have LF cameras with movement so that we don't have to use f64 where there is basically no other option in 35mm format but to use f16?

 

[DREW WILEY]

To completely negate the size advantage of 4x5 over 35mm, you'd need to leave the lens cap on. In any hypothetical contest between Godzilla and Bambi, the outcome (stomp splatter) is highly predictable. The only advantage the little deer has is running faster.

Smaller apertures and view camera movements are not mutually exclusive. With 8x10, I try not to stop down below f/45 unless I have to. For example, the image circle of a particular lens, combined with a significant amount of rise or tilt, might not be sufficient to decently cover this size film unless you do stop down to f/64.

Nevertheless, 8x10 film has about 60 times the surface area as 35mm film. That means even if there was a bit of diffraction setting in around f/64, you'd need a pretty big enlargement to detect it. 8X10 film enlarged to a 30X40 inch print is equivalent to a 35mm frame being enlarged to a 4x6 inch snapshot.

 

[Alan9940]

The general public can't tell the difference between a Cibachrome 30X40 from old Ektachrome 64 4x5 film, shot with an old 210 Symmar S lens, and enlarged with an old Componon S, versus what I do today, shooting with superb Fujinon A lenses in relation to current finer-grained 8x10 film (and 4x5), and enlarged onto Fujiflex using far superior Apo Nikkor f/9 graphics lenses. But I can tell the difference, and it gives me satisfaction.

Dang, Drew, you just described my photo and darkroom gear! I do, however, shoot with Fuji A and C lenses on my 8x10 but I contact print those negs.

 

[DREW WILEY]

I sold off all my well-used Schneider lenses and replaced them with new Fuji ones back when the German Mark was high against the dollar, but the Yen particularly low. I even turned a cash profit. My most employed 8x10 lenses are the Fuji 360A and 450C; but I sometimes also use a 250A and 600C.

Contact printers can get away with f/256, and nobody will notice.

 

[cliveh]

Try looking at the picture, rather than the resolution.

 

[MattKing]

If you are trying to make huge prints, and your budget is constrained, it may be that you have to factor in market prices for very high end lenses for the various formats.
It's tough for the members on Photrio to help with that.

 

[brbo]

Anyone wants to bring out pen and paper and compute at what aperture a pair of equivalent lenses become diffraction limited on a 100lpmm film for 35mm and 4x5"format and how much further you need to then stop down a large format lens to negate all of the 5x linear size advantage of LF?

But (consider that I'm not much of a LF photographer), don't we have LF cameras with movement so that we don't have to use f64 where there is basically no other option in 35mm format but to use f16?

Ok, if I try to engage my poor little brain...

Lens, regardless of format, will get diffraction limited on a film with set resolution, at the same aperture. But since larger film needs less magnification to print at the same size as smaller film, diffraction will effectively cancel out the advantage of larger format (like f64 on 4x5" instead of f16 on 35mm).

I've never used f64 on 4x5", but do use f16 on 35mm if I can't help it (fast film, no ND filter at hand).

(this is all under assumption that film has no grain and that will always play against smaller format (but longer exposure times will play against larger formats))

 

[Alan Edward Klein]

Logistical issues : With larger formats, like 8x10, an equivalent perspective requires a longer focal length lens than 4x5, hence you are working with a shallower depth of field at comparable aperture, so might need to stop down proportionately to get the same depth of field (f/45 for 8X10 instead of f/22 for 4x5, for example). Of course, the nature of view camera movements and selective composition offsets this to an extent.

The bigger the film, the more risk of it sagging in a sheet film holder and losing some of its acute focus. Solution: use a special adhesive or vacuum 8x10 holder.

How do you intend to print? With inkjet the format distinction makes little difference. But with acute optical printing, I'd rather enlarge an 8x10 original to 30X40 inches than a 4X5 original. Some of this has to do with hue saturation, some to sheer detail, especially in high-detail capacity media like Cibachrome or Fujiflex. There simply something extra there. But I do both.

The general public can't tell the difference between a Cibachrome 30X40 from old Ektachrome 64 4x5 film, shot with an old 210 Symmar S lens, and enlarged with an old Componon S, versus what I do today, shooting with superb Fujinon A lenses in relation to current finer-grained 8x10 film (and 4x5), and enlarged onto Fujiflex using far superior Apo Nikkor f/9 graphics lenses. But I can tell the difference, and it gives me satisfaction.

No way I'm personally going to color print 6x9 beyond 20X24; and even that's dependent on the very sharpest current films like Ektar 100.

I use Velvia 50 for color shots and Tmax100 and Tmax 400. Unfortunately, Fuji no longer makes it in large format but still does in 120. What would be the largest print for Velvia 50 in 120(6x7cm) you would use? What about for the Tmax 100 and 400?

 

[Harry Callahan]

I have heard people say that for larger than 4 x 5 negatives, there are diminishing returns on increasing resolution (line pairs visible) in prints because of increased diffraction. Is this true? This question is about enlarged prints where the prints are considerably larger than the negative. The question is NOT about contact printing.

If you step up to a bigger format there are diminishing returns, but not necessarily due to diffraction.
I`ve seen a lens test, where several lenses for different formats had been tested and the best 35mm lens had around 100ll/mm. The best medium format lens had around 80ll/mm and the best 4x5 lens had around 60ll/mm (across the entire negative. There was a 4x5 lens which did 80ll/mm, but only in the middle of the negative on the edges it was at 60ll/mm).
This means if you step up from 35mm to 6x6 you have a negative which is about 4 times larger, but it won`t be 4 times sharper; it may be three times sharper than 35mm. When stepping from 35mm to 4x5 you have a negative which is about 12 larger but it only may be 6 times sharper. This does continue for even bigger formats.
If you now want the same DOF with 4x5 as you have on 35mm you have to stop down more - and then you`ll loose additional sharpness due to diffraction.
If you print a 4x5 negative you also need to stop down the enlarging lens more, because otherwise contrast would be too weak and curvature of field could be problematic. Then you could loose sharpness due to diffraction - if your 4x5 negative had 100ll/mm. But it probably won`t because a good 4x5 lens will give you about 60ll/mm - in B&W of course.

So there are diminishing returns, but not necessarily due to diffraction - but there can be additional losses because of diffraction.

EDIT:

They were using the same film for all lenses and formats, i think it was T-Max 100. A good but "ordinary" film. If you used a high-resolution film for 4x5 to get 100ll/mm on the negative, then you could run into losses by diffraction in printing. But when using "ordinary" film sharpness on the bigger negative will be reduced anyway, so diffraction in printing shouldn`t be a problem.

 

[DREW WILEY]

I seldom like going bigger than 16X20 from 6x7 negs or chromes, Alan. An exception would be 20X24 prints from Ektar 100. I really prefer 6x9 anyway. 4X5 sheet film handles a lot better than roll film in the darkroom. You can make as big prints as you want to, but eventually run into the "normal viewing distance" nonsense to justify it. The normal viewing distance for a Marlboro Man billboard is a quarter mile away driving 70mph.

For MF work, I prefer TMX 100. TMY400 is exceptionally fine grained for its speed, but begins to show evident grain in 16x20 enlargements. Still, there are times you need the extra speed.

 

[Dan Fromm]

Lens, regardless of format, will get diffraction limited on a film with set resolution, at the same aperture. But since larger film needs less magnification to print at the same size as smaller film, diffraction will effectively cancel out the advantage of larger format (like f64 on 4x5" instead of f16 on 35mm)

Huh? A good approximation for diffraction limited resolution in lp/mm is 1500/F#. At f/45, the diffraction limit is ~ 30 lp/mm. The minimum acceptable resolution in the final print is 8 lp/mm so a negative shot at f/45 can't be enlarged more than ~ 4 times. The largest print, if all this is more-or-less correct, from a 4x5 neg printed full frame is 16" x 20". From a 35 mm printed full frame, 4" x 6". brbo, what have I got wrong?

 

[bluechromis]

Thanks for the responses. As to what I intend to print, I have only printed 35 mm and medium format so far. As I delve into 4 x 5, I envisage I would do some 16 x 20 regularly and will experiment with 20 x 24. The comments have shown me that 4 x 5 will be adequate for what I might do with enlargement prints. I am actually not obsessed with chasing the most extreme resolution. There was some intellectual curiosity behind the question as well

 

[Harry Callahan]

Thinking about it, the statement you heard *could* have been true like a hundred years ago. Back then lenses were uncoated, so you needed to stop down more than today. If you printed a format bigger than 4x5 you may have used a lens having 180mm focal length - and if this lens was an uncoated triplet you may had to stop it down to f22 or f32, where you indeed could have had reduction of sharpness by diffraction... if the negative have had high sharpness... which wouldn`t have been too likely because a hundred years ago taking lenses also weren`t as good as today...
...but it`s possible that this statement once was true to some extend...

 

[DREW WILEY]

I always aim to stop down a 4x5 lens to f/32, or at least f/22; and I have some of the finest MC later lenses. As I already mentioned, film does not lie completely flat in a typical holder, and stopping down a reasonable degree helps that issue. Second, you're going to get a more effective image circle stopping down. Third, most subject matter isn't going to lie on a flat plane head-on, but will have focus variations which even camera tilts and swings can't fully correct on their own.

Type of coatings, if any, is unrelated. That might affect the degree of flare if an effective shade is not in place; but depth of field is a different issue.

 

[gary mulder]

I like large prints ±40 inch wide. At home a have 7 - 9 hanging on the walls. It gives me a “window” to landscapes. It’s about aesthetics. It has to be a “nice" print. No more no less. The only thing concerning resolution is that it hasn't to be distracting. In the same way other technical aspects are never to be the purpose. In the past I printed from 4x5 and 8x10 in my dark room. Prints from 8x10 have a (very) slight aesthetic advantage. In the way they are more “relaxed”. Maybe that there is more definition in gradients than there is hard resolution.
The same can be said about digital 24x36mm sensors versus 40x54mm sensors. Even if the pixel count is the same.
Oops wrong forum. This is a analog thread.

 

[koraks]

Well, I don't think digital is as taboo here on Photrio as it might have been in the past. At least, I hope this is the case. So there's that. Also, as you stated, the format question applies to both film and digital, so considering it is fair game IMO. I don't shoot MF digital so can't comment, but my experience with the comparison between APS-C and FF suggests a similar pattern to what you noticed. Is it pixel count, diffraction, or something else? I really don't know.

I do know that you showed me one particular example of an enlarged color print from 4x5 and one from 8x10 of a similar scene; as I recall these were part of your sunflower series. The difference indeed was quite subtle and I remember we discussed it in terms of a somewhat vague construct of 'volume' or perhaps 'presence'. There was a difference, it was artistically relevant (to an extent), and I found it difficult or impossible to objectively quantify. The latter doesn't affect the relevance, obviously - just makes it trickier to discuss.

What I like about your post is that you (and I'm nodding also to @cliveh here, who made a pertinent remark above) relate this subject to the artistic intent or the impact of the image as such. In our discussions you have sometimes said that 'size matters', and it really does. Some images need to be big, others work better at an intimate scale. In my recent 'work', I've run into this quite prominently. I've mostly thought of it in terms of acutance, but that doesn't entirely cover it. In the end, the question is how much I'll have to strain my back to get the job done - with the job being the print on the wall that conveys what I intended to capture in the first place. Diffraction is somewhere in there, but it's buried pretty deep under several layers of higher-order considerations, I feel.