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View Full Version : Hey smarter-than-me-people: what do you make of this article?



altec2
23-Feb-2012, 19:12
http://www.photodo.com/topic_138.html

It argues that:

To conclude, with a wide aperture and short depth of field the sharpness is better with a larger format. When the lens is stopped down to get a deeper depth of field the difference between the different formats decreases. Above about f5.6 for 35 mm (f11 for 6x6 cm, and f22 for 9x12 cm) the difference in focus between the formats is insignificant. But this is only before we consider the film's effect on sharpness.

Peter Gomena
23-Feb-2012, 19:37
Two things:

First, take the source. It is written for a 35mm lens producer who is arguing the strengths and benefits of the format.

Second, the comparison is based on mtf curves and analyses of test charts.

It's a great apples/oranges article that tells me very little about actual photographs. If there is no real quality difference between formats, why are there different formats?

Peter Gomena

Old-N-Feeble
23-Feb-2012, 20:01
I'll take a Minox over 8x10 ANY day... LOL!!! I AM JOKING, folks.

Louis Pacilla
23-Feb-2012, 20:02
Two things:

First, take the source. It is written for a 35mm lens producer who is arguing the strengths and benefits of the format.

Second, the comparison is based on mtf curves and analyses of test charts.

It's a great apples/oranges article that tells me very little about actual photographs. If there is no real quality difference between formats, why are there different formats?

Peter Gomena

+1. Very well put Peter.

Ken Lee
23-Feb-2012, 20:32
http://www.kenleegallery.com/images/forum/targets.jpg

Comparing image 6 (4x5) to 4 (35mm), the author proposes "This image is the sharpest one, but the difference to 35 mm is suprisingly small."

He's entitled to his opinion, but it all depends on what we mean by "surprisingly" and "small" :rolleyes:

That being said, it's encouraging to know that with careful technique, smaller formats can perform as well as larger formats. It can be helpful, when traveling, to work with smaller, lighter equipment. Sandy King has shown some astonishing large prints made with a Mamiya 7 on Fuji Acros film. When shot at their best apertures, those lenses are among the best available in any format. When processed in a tanning/staining developer like Pyrocat HD, fine grain films that are held flat become very powerful capture devices.

Jay DeFehr
23-Feb-2012, 22:17
I'm no mathematician, but it seems he's stacking the deck against larger formats. The equation he uses to arrive at the various apertures seems dubious to me. When he divides 150/50 to get three, he's using linear units, but then he applies linear units to a geometric progression, and that doesn't seem right to me. To me, 3 x f/8 is not f/22. 2x f/8 = f/11, 2 x f/11= f/16, and 2 X f/16 = f/22. That seems a huge discrepancy. I'm not sure I buy his rationale for decreasing the aperture of the larger formats, at all. Doesn't the difference in CoC/enlargement factor equalize the differences in dof at a given aperture, given equal perspective and magnification? It seems his entire argument is based on the premise that larger formats must stop down more than smaller formats to achieve comparable dof, and I'm not convinced that's true.

Also, am I the only one who thinks the 35mm Tmax doesn't look sharper than the 9x12 Tri-X? And isn't there more to image quality than sharpness?

It's not news to me that films like Tmax and Acros allow for very high quality images from small formats, especially when paired with very high quality lenses, but I think the argument that the differences in formats is not significant is specious and I think the data is not very reliable.

I think the important differences between formats are in the way they can be used. If you want to shoot handheld, in low light, LF has little to offer over smaller formats.

polyglot
23-Feb-2012, 22:52
If you consider only diffraction as your source of unsharpness, then he is right, there is basically no difference between formats for a given depth of field. However, diffraction is not usually the limiting factor except in some very special cases with the very best optics... which means that most 35mm lenses don't reach their best until about f/8-f/11, which is the same DOF as about f/28-f/38 on 4x5. If you're willing to trade away some depth of field, greater sharpness is available from the larger formats.

The above analysis also assumes infinitely fine-grained film, so smaller formats lose out there as well because the film (or pixel pitch) can be limiting even where diffraction is not.

Way Beyond Monochrome has a nice graph illustrating the interaction of aperture diffraction, format size and max supportable print size (from lines per picture-height). Short version is: there really is a (resolution) benefit to shooting larger, though it's less than the ratio of film sizes would lead you to expect. The downside of course is that you need much more light.

Bruce Watson
24-Feb-2012, 06:19
To conclude, with a wide aperture and short depth of field the sharpness is better with a larger format. When the lens is stopped down to get a deeper depth of field the difference between the different formats decreases. Above about f5.6 for 35 mm (f11 for 6x6 cm, and f22 for 9x12 cm) the difference in focus between the formats is insignificant. But this is only before we consider the film's effect on sharpness.

Hate to tell 'em, but there's a hell of a lot more to photography, in any format, than just "sharpness".

E. von Hoegh
24-Feb-2012, 08:06
Fallacious.

DrTang
24-Feb-2012, 08:20
dumbest thing I ever read


All they are doing is testing film and lenses - big whoop

the point is..one has to enlarge the 35mm neg X times to view it... and the large format neg..many less times if any


The point of taking photos is to look at them (in theory I guess).. so they are only comparing at half of the finished equation



"...viewed with a microscope..." - - -hahahahah - yeah right

jp
24-Feb-2012, 09:56
It's just a bunch of lenses and film I'm not likely to use, even though I use 35mm, MF, or LF. I don't use tmax100, hasselblads, or zeiss planar 35mm lenses or sironar LF lenses. Change a lens or film and his tests are useless.

From a non-technical overview, it's quite clear the LF is tops, and there is mention of movements for LF bringing additional focusing flexibility.

I'm not into lens charts and such. I use a format based on it's suitability to a task and based on the lens choices. I have lesser interest in the latest and greatest via consumerism, and more interest in historic aesthetics and lenses with new subjects.

Drew Wiley
24-Feb-2012, 10:24
Idiotic comparisons like this pop up rather frequently, esp on digital photog sites, generally
written and believed by folks who have never printed from large format to begin with. And
basically, you take a worst-case scenario with the bigger film (imprecise film plane, grainiest film you can find, no plane of focus control using movements) and compare it with
a best case scenario with the little camera. About all one can say, is just go out and make
a large print with the finest technology you can find, and it will still look like mush compared to even a garden-variety LF print of the same size. It's no use arguing with the
geek mentality. But for 35mm work per se, some of those new Zeiss lenses are indeed very
desireable.

Jim Jones
24-Feb-2012, 11:02
As I recall, with quality lenses diffraction may become noticable when the entrance pupil is less than about 6mm. The hyperfocal distance is about 2000 times the entrance pupil for modest print size. This much math we had to cope with in elementary school, and may be more convenient than charts and tables in the field, let alone MTF charts. Someone with more facility in explaining math might present this more lucidly than me with many decades old schooling clouded by a poor memory.

Dan Fromm
24-Feb-2012, 11:47
Idiotic comparisons like this pop up rather frequently, esp on digital photog sites, generally
written and believed by folks who have never printed from large format to begin with. And
basically, you take a worst-case scenario with the bigger film (imprecise film plane, grainiest film you can find, no plane of focus control using movements) and compare it with
a best case scenario with the little camera. About all one can say, is just go out and make
a large print with the finest technology you can find, and it will still look like mush compared to even a garden-variety LF print of the same size. It's no use arguing with the
geek mentality. But for 35mm work per se, some of those new Zeiss lenses are indeed very
desireable.

Drew, it is just, or wasn't just, digital geeks. Do you remember H&W Control film and developer and the fuss the Leicanuts of the day made about the lack of need for larger formats?

Jay DeFehr
24-Feb-2012, 13:12
I don't think the article was a total waste of time; it reminded me how good Tmax 100 is. TMX was the fist film of its kind I ever used, and I remember vividly being blown away. My standard film then was Verichrome Pan, and I developed in D-76, as per the tutelage of the codgers at the photo shop. They had nothing but contempt for TMX, so I had to buy it elsewhere for fear of recrimination and ostracism.:eek: Not long after, VP was discontinued, and I switched to TMX. I haven't used it in a while, preferring Acros, but I could be happy with it if Acros was not available or convenient. To be honest, I use TMY-2 99% of the time, and nothing else comes close to that film.

onnect17
26-Feb-2012, 21:27
The article makes perfect sense to me. The whole point is that if you use impeccable technique, fine grain/high resolving power film and high quality lenses used at their best apertures, you can take photographs with 35mm and medium format film that are not too much inferior to those shot on 4x5 for many purposes. There is no claim that the results are equal in all respects, but the article does validate the idea that large format does not offer as much increase in image quality as is popularly assumed. No big mystery there (one of those diminishing return things).

Ditto - I'm sure I getting more details with my combination apo-sironar-s + 4x5 + drum-scan than many ?lens + 8x10 + epson. Bigger camera does not means better details.
Not to mention saving 4x emulsion :)

Robert Jonathan
27-Feb-2012, 06:13
Just read Tim Parkin's camera comparison, and then you'll really know what the difference between formats is.

onnect17
27-Feb-2012, 13:29
Just read Tim Parkin's camera comparison, and then you'll really know what the difference between formats is.

Robert,
I would not put to much weight in Tim's comparison. I second the post mentioning the chapter in "way beyond monochrome..." book.
Why? Just a couple of points:
- Tim should have used the same lens to compare the 4x5 and 8x10.
- Based on the images, the drum scanner used is defective. It's hard to ignore the "waving" and out of focus.
- Only one target located on the side. I can even see the chromatic aberration. I would use at least 5 targets: Center-Middle-Border and two more positioned vertically.
...
Armando

Bob Salomon
27-Feb-2012, 14:53
The diagonal of a 35mm negative is not 50mm. It is closer to 44mm and the diagonal of a 45 is closer to 135mm.