How sharp can you get?

[sanking]

But the Mamiya 7's 80/4 and a few others in MF are exceptions. There are many MF lenses where the resolution numbers are matched by LF lenses. C. Perez concludes that at similar cost of ownership, LF and MF systems produce the same resolution to film. In the case of the Mamiya 80/4, it produces better resolution to film than the best LF lens, but still doesn't match the total resolution on film-area.

I can only really speak personaly to a comparison of Mamiya 7II and 80mm lens with a high quality lens on a quality 4X5 system. The comparison film was Portra 160, and the MF and LF film was drum scanned.

In terms of absolute image quality the 4X5" negative did beat the 6X7 cm negative, but only by a tad. In a print I don't think you would see any difference at all in sharpness until going beyond 30X35" in size, but you might see a bit more grain in the print from the MF negative, but not necessarily as use of noise reduction software might neutralize grain.

This comparison was made same film for both formats. Bear in mind that for the same DOF you can use a slower speed film with finer grain and greater sharpness with MF than with 4X5, or you can use an aperture of about 1.5 stops greater, with less diffraction.

Either way, for maximum image quality individual technique is probably more important than the format. Grain, for example, will depend highly on how you print, scan, what scanner, technique used, fluid mounted or not, etc.

Sandy King

[dh003i]

I can only really speak personaly to a comparison of Mamiya 7II and 80mm lens with a high quality lens on a quality 4X5 system. The comparison film was Portra 160, and the MF and LF film was drum scanned.

In terms of absolute image quality the 4X5" negative did beat the 6X7 cm negative, but only by a tad. In a print I don't think you would see any difference at all in sharpness until going beyond 30X35" in size, but you might see a bit more grain in the print from the MF negative, but not necessarily as use of noise reduction software might neutralize grain.

Yea, but software can do that for 4x5" too. But then, the comparison point goes up, so maybe you won't notice it until an even larger size. So of course you have a good point.

This comparison was made same film for both formats. Bear in mind that for the same DOF you can use a slower speed film with finer grain and greater sharpness with MF than with 4X5, or you can use an aperture of about 1.5 stops greater, with less diffraction.

Yea, but if you look at the comparison I did, I was comparing lenses at equivalent DOF (although different angle of view, as I wanted to compare the sharpest lenses I saw on C. Perez' site). Although in general, your statement will hold. So I think that is accounting for that issue.

I think that broadly, theoretically, when accounting for image-area, diffraction limits at f-stops, equivalent focal lengths, and DOF, all systems should theoretically produce the same final resolution for an equivalent image. It's only in the empirical world where that ceases to be; in LF's favor because it's much easier to reach diffraction-limits at higher f-stops for equivalent DOF; although in smaller formats favor because it's easier to design high-quality small lenses.

Either way, for maximum image quality individual technique is probably more important than the format. Grain, for example, will depend highly on how you print, scan, what scanner, technique used, fluid mounted or not, etc. There are no free passes to image quality paradise.

Sandy King

Oh yea, for sure.

But me, I kind of love the idea of being able to use the tilts to get all of what I want in focus.

IF I were to get a medium format, I think I'd use an adapter for a 4x5 back; although then I suppose I'd lose the resolution-to-film advantages of the best MF lenses, as they aren't to be mounted in copal shutters. That is, the modern MF lenses can't be put in shutters, unless I'm mistaken.

If there were a modern tack-sharp MF lens that could be put in a shutter, it'd make an interesting proposition for using on a 4x5 (IF it had enough coverage to use tilts on the 6x7 format).

The GW690III seems like a nice system for it's tilts, although the only lens where it was tested showed it being about equal to the better LF lenses.

PS: One interesting thing is Cramer's article comparing the P45 Phase One Back to a 4x5 with Fuji Velvia film, and it seems like the P45 is just about as sharp. That's impressive for sure; but the P45 is $30+k. So for 30 times the cost, and many decades later, digital has finally caught up with 4x5 film. Kind of funny how for cost-equivalence per quality, the digital formats are still way behind film for what would be most people's uses.

[Ivan J. Eberle]

Chris Perez and Kerry Thalmann did yeomans's work with their resolution tests; however, if you look at the footnotes they also did these over a period of time with several different cameras (some of which they admit had film flatness issues).

Has anyone tested and posted comparisons between the best of the film-era lenses, and the new class of small circle digital lenses? These are supposedly (at least anecdotally) among the best resolving LF/MF lenses available ever made and would seem suited to MF film as well, where ultimate resolution is the prime consideration.

[sanking]

IF I were to get a medium format, I think I'd use an adapter for a 4x5 back; although then I suppose I'd lose the resolution-to-film advantages of the best MF lenses, as they aren't to be mounted in copal shutters. That is, the modern MF lenses can't be put in shutters, unless I'm mistaken.

I believe that some of the reason, in addition to the quality of the optics, for the very high performance of the Mamiya 7II system is due to the precision of the film plane to lens and to the operation of the pressure plate in holding the film flat and at the right plane. Perhaps some of the modern roll film holders offer this precision but my experience with older roll film adaptors for LF is that they did not.

Sandy King

[Robert Fisher]

Sandy & others, do you know of a database that might have MTF charts on Fuji GX680 lenses? Thanks

[Robert Hughes]

To me, the Mamiya is is the best alternative to LF. It's hand holdable and sharp.

But aren't these two characteristics mutually exclusive? My Busch Pressman is hand holdable and sharp, too - just not at the same time.

I've just gone out to the Mamiya7.com fan site to look at some MF photos, and they do look nice and very sharp - but oh, so grainy! I don't see that in 4x5.

But reading about the relative advantages of smaller formats gives me a new appreciation for the tiny formats, like Super 8. It's almost amazing that you can get discernible images at that size - of course it helps that you have a bunch of them in sequence to fill in the blanks from all that grain noise.

[sanking]

But aren't these two characteristics mutually exclusive? My Busch Pressman is hand holdable and sharp, too - just not at the same time.

I've just gone out to the Mamiya7.com fan site to look at some MF photos, and they do look nice and very sharp - but oh, so grainy! I don't see that in 4x5.

Many of those photos were probably made hand held with high speed film. Many people appear to use Mamiya 7 that way.

I work with Mamiya 7 pretty much the same way I work with LF. I put the camera on a tripod, compose the scene and then set the shutter speed in accord with optimum aperture for the scene. If grain is a consideration, as it often is for me because I want the same smooth tonal values in MF that I see in LF, I use a slow, fine grain film. My experience is that a 6X7 cm negative with either Fuji Acros or Tmax 100, scanned with fluid mount, can be enlarged to about 30X35" with excellent sharpness and no apparent grain.

As was mentioned earlier, for the same DOF and shutter speed you have the option of using a film about two stops slower with MF than with LF. This pretty much equalizes grain and gives about the same smooth tonal values with both formats for a given print size.

Sandy King

[dh003i]

I believe that some of the reason, in addition to the quality of the optics, for the very high performance of the Mamiya 7II system is due to the precision of the film plane to lens and to the operation of the pressure plate in holding the film flat and at the right plane. Perhaps some of the modern roll film holders offer this precision but my experience with older roll film adaptors for LF is that they did not.

Sandy King

Oh yea, I guess that would be a bigger problem with roll film, while it isn't really as much of an issue with sheet film. But isn't there sheet film available for MF cameras?

[Ben Syverson]

Oh yea, I guess that would be a bigger problem with roll film, while it isn't really as much of an issue with sheet film.

Actually, lots of people claim to have issues with film flatness when using standard LF film holders. The theory is that while rollfilm can be stretched and pressed onto the film aperture, sheet film can "rattle around" within the guide rails.

I've never had problems with film flatness, but I shoot color film, so what do I know? I'd probably never see the difference.

[Doug Dolde]

The biggest problem with the Mamiya 7 especially if you are shooting color transparency film is the inability to accurately place a grad filter. Unless your image has no sky in it this will be a major downside. But I agree with the sharpness of M7 lenses...amazing !