Large vs Medium format lenses

[uniB]

I've heard varied answers to this question, so I thought I'd ask...

Do large format lenses (on 4x5) resolve less detail than medium format lenses? Specifically, when I use my 6x6 roll film back on my LF, will I get result with less detail than if I use my Hasselblad?

And, on the same subjet, how far off LF detail is a Mamiya 6 or 7 going to have, given that they have reputedly some of the best quality lenses going?

[Bob Salomon]

See if you can find the March 1992 issue of "Color Foto" magazine on line. It had an article "Scharfschuetzen" and a second article "Spitzenleistung durch Verzicht" Which did a test between all MF camera lenses available then as well as the Fujinon EBC lenses for the 6x8cm camera and large format lenses.

While most of the lenses are no longer current it will answer your question. The articles are in German but the charts and graphs and scores are easily understood by non-German speakers.

[Ben Syverson]

Depends on the lens and how you use it. At the stops you tend to use in LF (f/22 and up), diffraction starts to eat into sharpness.

If your LF lens resolves 40 lp/mm, you're under-resolving color film, and definitely lagging behind what the best Hasselblad and Mamiya lenses can do. Some LF lenses can do much better than 40 lp/mm, and some do much worse.

At 40 lp/mm, you're resolving 5000x4000 line pairs in 4x5. The Mamiya 7 lenses are quoted at 100-120 lp/mm, which means you're resolving around 6900x5600 line pairs, providing your film can keep up. For color film, I figure 67.2 lp/mm, which means you could pull 4623x3763 line pairs from the 7 -- about the same as the 40 lp/mm 4x5.

The advantage of LF is not necessarily resolution but flexibility -- with a rollfilm back, you have full access to movements.

[BarryS]

I have a Hasselblad V system and haven't made any scientific comparisons, but find it depends on the LF lens. In my experience, every single Zeiss Hassy lens is extremely sharp and contrasty, but I don't see the same consistency with LF lenses. Some are probably just as good like the Nikkor 90mm SW f/8, but others don't seem quite as sharp.

[Lachlan 717]

First, you're only as good as the quality of glass you have. Generally, a Zeiss lens will come from a lineage of highest quality optics at a relatively high price. In order for Zeiss to source the best components, you will pay a premium. You will also pay for quality control (just as you theoretically will buying Linhoff/Sinar badged Schneiders), whereby a lens will be tested before it is released to market. Obviously, the tighter the tolerances, the more lenses will be rejected. This will also add to price.

I doubt Congo a) uses the highest quality glass available and b) throws many lenses out!

It is like buying a pair of sunglasses from a gas/petrol station - you get what you pay.

Second, you need to be very careful about the testing methods. A 'Blad lens, when tested, will be mounted onto a 'Blad body. Some high cost and high precision engineering has gone into ensuring that the lens will be as close to perfectly aligned as possible for such a camera setup. This is both perpendicular and centred.

On the other hand, when a LF lens is tested, by design a bellows camera is nowhere near as precisely aligned. Sure, the Tester will do his/her best to ensure standards, film holders and lens boards are all in alignment; however, not being a fixed setup, a modicum of movement will occur when lenses are changed. And the centring of the lens and the camera's movements will not necessarily be anywhere near at their optimum.

All of that being said, don't get too caught up in the "Megapixel" phenomenon. Regardless of resolution, most photographers' skill will determine the sharpness of the final image, not the lens used.

[Ken Lee]

The issue has been explored here a number of times. I think we've done a fairly good job with it.

This recent discussion might help: How Sharp Can You Get ?

[uniB]

Thanks for the info folks, and sorry Ken, I didn't look hard enough, although the post you point out doesn't go into the issue I was specifically talking about which was using a 6x6 roll film back and therefore not using the whole 4x5 image area.

As always trying out side by side comparisons are the best way to answer my own question, but trudging out with a Hasselblad and all my LF kit would lead me to an appointment with the osteopath!

[Drew Bedo]

I would think that the amount of enlargement required to make equal sized prints would play a part. A Hassalblad or Mamya-6 negative has just under 9 sq in of area, and is enlarged just over 9 times to make an 8x10 print at 80 sq in. An 8x10 negative undergoes no enlargement to produce an 8x10 print. A 20x24 in print from that negative is still only a 6x enlargement. A print of that size from a 6x6 cm negative is about 53X. Doesn't this play a major role in the LF vs MF comparison?

[Ivan J. Eberle]

Actually, Drew, none at all--since the OP was talking about shooting 6x6 on his LF camera using a roll-film holder. Same film size, different lens.

I think the answer will depend not only on what film the OP is using, but whether shooting in high contrast light, and at what f/stop and how 3D the subject matter. The best lenses of all formats seem capable of out-resolving many emulsions in low contrast light, with flat subjects, at the prime f/stop for the design. Landscapes tend not to be shot in greater than 1:6 contrast light, as this is usually more aesthetically pleasing. But it means with excellent glass that the film resolution is often the limiting factor.

Though it's much easier to move up to 6x9 or 6x12 (less so, 6x17) using the same LF glass on a 4x5. At extremis this use of roll film will trounce the Hasselblad, all other factors (film flatness, wind) aside.

One thing that a LF camera with a 6x6 roll-film holder might buy you versus a 'Blad is the lens standard or back moves to get the film plane more parallel to the subject plane so that you might use a prime f/stop instead of f/22-32-45. (This only works provided you are shooting the 4x5 by swapping out the roll holder after focusing on the GG, not using a rangefinder and no movements.)

[uniB]

Thanks Ivan, that's right, my question was specifically related to using a 6x6 roll film back so the film area is the same on both the LF and the 'Blad / Mamiya 6. I like to make square images and using the roll film back allows me a greater focal length with my LF lenses due to the crop factor. It is great to be able to use the LF movements to allow for close focusing which I can't get from the 'Blad.

I should have mentioned the film and lenses – although I've been using neg film, mainly Provia 160nc, I'm going to be using Astia almost exclusively from now on. I tend to stick to around 5 stop scenes and use filters to control this – I know Astia can handle a little more.

Lens wise I mainly use a Nikkor 90 f4, Fujinon A 180 and 240, and a Nikkor M 300mm f9. I'm not sure about the resolving power of these lenses at all.