Finder
Veteran
charjohncarter said:
Actually, you don't. Just compare relative size with system MTF. You will see the the larger format has a better result. Given equal targets, the larger format can reproduce details with greater accutance because it can use larger circles of confusion. Since the relative granularity is lower in medium-format, you have greater "tonality." As posted above, what is there to figure out?
Finder
Veteran
FrankS said:
Urban myth Frank, unless you have average lens resolution statistics? Especially, with all those standard zooms given away with cameras.
charjohncarter
Veteran
Well, I think there is more to it than circles of confusion: internal lens and camera flare, geometry of enlarger light sources, geometry of enlarger lens, inverse square rule of light intensity, base fog and base material and there relationship to light source distances, light scatter ratios between 120 and 35mm, light color temperature and its relation to base material and emulsion. There are, I'm sure, many more variables. Don't think small. But as I said before it probably doesn't make any difference because if it were solvable, someone smarter than you or I would have worked it out.
keithwms
Established
You don't need an optical physicist to understand this, but I'll give my opinion anyway- just look up "circle of confusion."
Regarding the crop test, yes, some detail and tonality is lost when you crop down a MF neg to 35mm, but that loss of information is less than the difference in size of the two formats. MF lenses not ~1.5x - 2x worse than 35mm lenses. To put it another way, the difference in acceptable enlargement factor (as indicated by the CoC) exceeds the difference in lens performance.
As I think I mentioned before, the horse IR shot in my RFF gallery is a 1/3 frame crop of 6x6cm, so, not too different from 35mm. My opinion is that crop enlarges acceptably to about 11x14 or so.
Regarding the crop test, yes, some detail and tonality is lost when you crop down a MF neg to 35mm, but that loss of information is less than the difference in size of the two formats. MF lenses not ~1.5x - 2x worse than 35mm lenses. To put it another way, the difference in acceptable enlargement factor (as indicated by the CoC) exceeds the difference in lens performance.
As I think I mentioned before, the horse IR shot in my RFF gallery is a 1/3 frame crop of 6x6cm, so, not too different from 35mm. My opinion is that crop enlarges acceptably to about 11x14 or so.
Finder
Veteran
sitemistic said:I don't know about this. I do know that a great lens designed for the 4x5 format becomes only an average lens when used with a 120 back. I've compared the results between 4x5 with medium format back and a true medium format camera and the MF wins hand down. The advantage in the 4x5 with the 120 back is the movements, not in resolution. I would assume the same would be the result if shot a medium format camera with a 35mm back. (Holgas excepted
But can you be more specific. The large-format lenses supplied with cameras like the Horseman 6x9 Pro or SW612 and Alpas and Silvestris don't seem to be giving sub-standard results. Will my Hexanon 35mm f/2 lens be better than my Speed Graphic Optar? Yes. Can the cheap 35- 70 Zoom Nikkor compete with my 4x5 APO Grandagon (which happens to be supplied with medium-format cameras)? Frank said average as if 35mm will always be better. Lenses among formats are closer than that. There is a large gray/grey area.
Now, it would be true to say that the resolving power requirements are more stringent as format decreases - lenses on point and shoot digital camera may even be better than what Leica makes for their rangefinders. But I cannot make such blanket statements as 35mm WILL have better resolving power than medium format.
Finder
Veteran
charjohncarter said:
Where are you getting all these factors and why do you even think they are relavant?? Just calculate componant and systemic MTF!
Why are you assuming that some of us here don't know the "answer"? How do you know it has not been solved?
Sparrow
Veteran
FrankS
Registered User
Finder said:
Let's exclude zooms. (Did I really have to specify that?) Resolution ability and data for 35mm prime lenses are almost always better than the resolution abilities of medium and large format lenses because the coverage required is much less and the lens element diameters can be smaller, which are easier to manufacture with precision.
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Roger Hicks
Veteran
True enough, and the 38/4,5 Biogon on an Alpa can give better than 90 lp/mm on the film even hand held -- superior to the same lens on an SWC because the camera is easier to hold steady and the 44x66mm Alpa format (masked down from 6x7cm) holds the film flatter. (Zeiss experiments and conclusions).Finder said:
I was at the Zeiss 'Meet the Presidents' event, courtesy of Alpa, and now, several years on, I have become quite well acquainted with several of the people involved. They are not bull**** artists. The evidence presented on film flatness/location was convincing -- and this, Zeiss themselves admit, is the ultimate limiting factor with the best current lenses. As 35mm is better located than most film, 35mm delivers the best quality.
Like the estimable Ctein, I have found that 125 lp/mm is the realistic on-the-film limit, and like him I've found it's not repeatable from frame to frame because of positioning variations -- even more true, I suspect, with the old thin-base 72 exposure Ilford films, though what killed these, I am sure, was that very few people want that many frames anyway. Realistically, 100 lp/mm is the most you can hope for, consistently.
Zeiss have demonstrated 200 lp/mm on the film with what they call 'focus bracketing', but sorry, life ain't long enough...
Cheers,
R.
Roger Hicks
Veteran
Because if Zeiss is still talking about unknowable variables -- about 'look' and the importance of taking pictures rather than relying on MTF curves -- then I am reasonably confident that most of the rest of us don't know either.Finder said:
Admittedly I don't call myself a genius -- I've let others do that, and it's happened often enough to be gratifying -- but with the utmost respect I'd be surprised if you knew more about this than Dr. Nasse at Zeiss (though he'd be a lot more humble about the extent of his knowledge than I am on his behalf).
Cheers,
Roger
charjohncarter
Veteran
Thank you Roger, I like that: unknowable variables.
David Goldfarb
Well-known
As far as MF backs on LF cameras go, much depends on the backs and lenses in question. Current LF lenses are generally as good as MF lenses, because they need to be able to work with smaller formats including digital. There can also be a world of difference between, say, a Graflex rollfilm back and a Linhof Super-Rollex back in the same format. Yet another issue is the focus accuracy--groundglass, scale focusing, Graflex or Kalart rangefinder, or Linhof rangefinder?
Other issues are the apertures that are usable and the shutter involved. For instance, I occasionally do a little impromptu bird photography with an old RF cammed 360/5.5 Tele-Xenar and a 6x7 Super-Rollex back on my 4x5 Linhof Tech V. The lens is an old design and not in great shape, but in good light for larger birds that aren't flying, it does pretty well. The maximum shutter speed on that lens is 1/125 sec., so in daylight, I'm likely to be working around f:11-16, at which point the quality of the lens is limited by diffraction, so the advantage of a lens that is sharper wide open is negated. With a MF camera that has a focal plane shutter, it would be possible to use a faster shutter speed and a more optimal aperture. Of course a wider aperture would be possible on the LF camera with ND filters or slower film, but then the slow shutter speed can become a limiting factor.
Other issues are the apertures that are usable and the shutter involved. For instance, I occasionally do a little impromptu bird photography with an old RF cammed 360/5.5 Tele-Xenar and a 6x7 Super-Rollex back on my 4x5 Linhof Tech V. The lens is an old design and not in great shape, but in good light for larger birds that aren't flying, it does pretty well. The maximum shutter speed on that lens is 1/125 sec., so in daylight, I'm likely to be working around f:11-16, at which point the quality of the lens is limited by diffraction, so the advantage of a lens that is sharper wide open is negated. With a MF camera that has a focal plane shutter, it would be possible to use a faster shutter speed and a more optimal aperture. Of course a wider aperture would be possible on the LF camera with ND filters or slower film, but then the slow shutter speed can become a limiting factor.
Finder
Veteran
Roger Hicks said:
What are you saying Roger, why medium format looks better than 35mm is not understood? Medium format looks better because of magic? I am sorry, you are going to have work harder than that.
So, there are qualities that can't be known yet exist in Leica images. Perhaps you can post some examples. Then we can see what you are talking about.
You are also going to have to develop a bit of a sense of humor if you are going to appreciate my tag line. (Also, I would not let the words of others go to your head - talk is cheap.) So I need to know as much as Dr. Nasse to answer the question why medium format looks better than 35mm? (Well, should I assume charjohncarter is right that the inverse square law is part of the problem?) Perhaps you can tell me why MTF cannot answer the question.
hofrench@mac.co
Established
Ronald M said:
I beg to differ here. A Yashicamat will make a better print than a Leica, simply on the strength of the larger negative. This is assuming two conditions, you're not shooting wide open, and you're not shooting into a situation where there's strong flare. The Yashicamat doesn't have modern multicoating. (I've got lots of negs and prints from all three of the cameras you mention: Yashicamat, Leica and Rolleiflex)
keithwms
Established
I confess I don't understand the point of cropping MF negatives down to 35mm, using LF lenses with MF backs, and talking about unknown variables and whatever. I'm losing the plot here....
Every format and every camera has its own merits and uses. They are simply different tools for different tasks. And at least in the film world, there are still many refreshingly different kinds of equipment available. It's enjoyable to sample them and simply to experiment and see what happens.
Every format and every camera has its own merits and uses. They are simply different tools for different tasks. And at least in the film world, there are still many refreshingly different kinds of equipment available. It's enjoyable to sample them and simply to experiment and see what happens.
RObert Budding
D'oh!
FrankS said:
This really isn't difficult to figure out - no need for a PhD in optics. There are plenty of MF and LF lenses that are very sharp . Then you get to factor in less required enlargement, too:
http://www.hevanet.com/cperez/testing.html
http://www.photodo.com/products.html?mountid=61&name=Mamiya+7
There is a reason that some folks choose to lug about large cameras. And there are situations (low light, fast-moving subjects, the need to travel light) when miniature formats make sense (even though you end up with inferior tonality).
hofrench@mac.co
Established
cmedin said:
Any Yashica-Mat will print better than a Leica from at least 5.6 up, provided that you're not shooting into the sun or in such a way that the lack of modern coatings affects results.
I print Leica, Yashica-Mat and Rolleiflex negs side by side all the time, and experience tells me the difference in negative size is a good deal greater than any difference in lens quality.
Roger Hicks
Veteran
For ther first, I am saying that image quality is not fully quantifiable; MF vs 35mm is a subset of this. For the second, I have already pointed out that many people -- including Dr. Nasse -- maintain that it cannot. I've said that I don't know why, and he doesn't know why.Finder said:
Cheers,
Roger
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