Large format vs. medium format

[Don Hutton]

Using f45 with the 110XL will result in negs with resolution below 30lp/mm - you will be getting nowhere close to what the lens is capable of at that aperture. At f16 (or f22), you should be getting over 50lp/mm compared with perhaps 60-90 with your MF set-up. Are you going to see that as a visible difference with a 10X loupe? No - simply not happening. To discern 50lp/mm + resolution, you'll be needing a more powerful loupe.

You're most likely observing the effects of dramatic differences in microcontrast caused by different formats. On smaller formats, because scenes are "condensed" (more to fit on a smaller frame), that has the effect of making everything look snappier or sharper because the contrast gradients are closer together on a given scene. That's why "wide angle" shots often look sharper on a lightbox - there's more detail and texture closer together than with a normal-longer shot of the same scene.

If you're concerned, get a target and test - it doesn't lie and will give you a very good idea of what parameters are observable at given magnifications.


And if you want to find out about how a hood helps - just shoot a scene with and without under "bright" conditions of a high contrast scene - you will be converted forever.

[David A. Goldfarb]

If your camera offers the option of a compendium (bellows) shade that attaches to the camera instead of the lens, that's usually the best option, because you can use it with any lens and adjust it for focal length and camera movements just short of where it vignettes, and they usually have filter slots on the rear standard. The shade will usually have some movements of its own, so that you can shade asymmetrically, if the camera movements require it.

Lee and a few other companies make compendium shades that attach to the lens with adapters.

I think it was Robert Zeichner who posted a good design for an adjustable barndoor hood around here somewhere.

Screw-in shades and rubber shades are less versatile, but better than nothing, and sometimes good options when a compendium shade is too cumbersome (in the wind or for handheld press camera use, for instance). Hama makes a rubber zoom hood with variable extension that's handy, if you go with a rubber hood.

Then there are things like the "Flare Buster," which is a card on a gooseneck with a clamp to keep direct light off the front element, or you can just use a card, your hand, a hat, or a darkslide, but this won't reduce excess image circle on all four sides of the projected image.

[Leonard Evens]

As others have said, it is the final print that counts. The short answer is that prints made from large format negatives need only be enlarged roughly half as much as those those made from medium format negatives, so the prints will appear sharper.

If you examine the negatives under 10 X magnification, you are in effect comparing what would happen if you cropped your large format images to medium format size.

Here are some facts that are relevant to comparing formats.

First, to make a comparison, you should compare lenses with the same angle of view. A 110 lens for 4 x 5 is comparable roughly equivalent to a 55 mm lens for medium format. You should also compare pcitures of the same scene taken under the same lighting.

A medium format lens will have somewhat higher resolution because the area it needs to cover is half as large and usually it need not allow for movements. The film plane is also likely to be better controlled. Finally, for the same depth of field, you can get away with larger apertures and shorter exposure times, which reduces problems of camera or subject movement.

As noted, large format lens need not be enlarged as much. If the resolution of the. medium format lens were twice as high as that of the comparable large format lens, you might end up with comparable results for both formats, but that is not true. Modern large format lenses do almost as well in resolution as comparable medium format lenses. In addition, since you enlarge only half as much, grain is less of a problem.

I spent over thirty years doing medium format, using a Rollei with a a superb f/2.8 planar lens and a Mamiya C3 with 105 mm and 180 mm lenses. I also used a Horseman 980 with t65 mm, 90 mm, and 150 mm lens. The Horseman is more comparable to my large format setup because it allows for movements and the lenses are designed for that. While some of my medium format prints are very sharp, they don't compare with my 4 x 5 prints of the same size.

While the enlargement factor explains a great deal of what you observed, other factors such as contrast also played a role. Another factor might be focusing. A medium format camera may have a focusing aid built into the focusing screen, and its infinity setting is likely to be pretty accurate. Also, the focusing (wide-open) aperture is larger, which may yield more accurate focusing,depending on how you focus in the two cases. To get comparable results with your f/5.6 110 mm Super Symmar XL, you should probably be using a 4 X loupe. Even so, it takes a while to learn proper focusing technique in large format.

[butterflydream]

The printing work of LF is also different from smaller formats in terms of local contrast. You can play much more flexibility. This was what LF charmed me even if I print small. Equally bad negatives I made with LF, MF and 35mm, LF can save better print.

[Eric Leppanen]

The links below document resolution tests performed on a variety of MF and LF lenses:

http://www.hevanet.com/cperez/MF_testing.html
http://www.hevanet.com/cperez/testing.html

In comparing the two formats, aperture makes a big difference, at least theoretically. A Mamiya 7 50mm f/4 lens at f/11 resolved 96 lppm at the center, whereas the sharpest SS110XL tested resolved 60 lppm at f/22. (A Mamiya 7 65mm better matches the angle of the view of the SS110XL, but it was not included in this test). My Mamiya 7 chromes used to have noticeably more "snap" than my 4x5 shots (as long as I did not stop the M7 all the way down to f/22), but typically not enough to offset the much larger film area of the 4x5.

Also, when shooting long exposures the 4x5 will be far more vulnerable to wind shake than MF, so I suspect your 8 - 30 second exposure times are impacting your results, even with only a slight, occasional breeze. I suggest trying another comparison in broad sunlight using a lens hood and shutter speeds of 1/60 or faster.

[Bruce Watson]

Using a 10x loup, the "sharpness" of the medium format negatives seems to literally jump out at me and is much more apparent than it is for the LF negatives.

It's not that the LF negatives are particularly soft or out-of-focus in themselves .... there is good detail there ..... but they seem to be lacking that overwhelming sharpness that I'm seeing in the medium format negatives.

Is this normal?? Am I doing a fair comparison?

IMHO no, you aren't making a fair comparison.

A 10x enlargement of a 6 x 7 negative is a 60 x 70 cm print. A 10x enlargement of a 4 x 5 negative is a much larger 100 x 125 cm print.

Said another way, a 60 x 70 cm print from a 4 x 5 negative is a bit less than a 6x enlargement.

So a fair comparison would be to compare 60 x 70 cm prints from both negatives, or use a 10x loupe on the 6 x 7, and a 6x loupe on the 4 x 5.

Or, you could reverse this comparison and make it between a 6 x 7 and a 35mm negative. Under the same 10x loupe, the 35mm negative will look sharper than the 6 x 7.

As long as you remember that there's a hell of a lot more to a good photograph than perceived sharpness you should be OK. Just don't let the testing get in the way of your photography!

[Andrew O'Neill]

Like someone stated earlier...make prints of same subject and composition from both negs sizes and then make your comparison. 8x10 prints should suffice. Even though the medium format negs will hold up very well, the LF neg will win.

[Tony Karnezis]

I think it was Robert Zeichner who posted a good design for an adjustable barndoor hood around here somewhere.

http://web.mac.com/razeichner/iWeb/R...%20pg%201.html

I bookmarked it when he posted a link to it on a previous post. Negatives taken with the barn door shade have noticeably more contrast than those taken with a round rubber hood.

[soeren]

So it seems contrast and not sharpness is the problem?
If you after scanning/printing your LF negs feel you need more contrast its back to the finetuning of exposure/development to suit your needs.
Kind regards

[Ken Lee]

As logical as we would like to be about this subject, there are many secondary factors, and certain intangibles, which arise when shooting, processing, and printing. These cannot be dismissed. If we isolate one factor alone, we can easily ignore the others.

If you don't have the time and resources to compare for yourself, then it's best to find some finished prints that someone else has made with a particular set of equipment and methods, and make your best personal judgment.

I'm sure that many of us have had the experience of seeing some Ultra Large Format contact prints - or some Minox images for that matter - and just knowing: that's the way I want to go.

Some may remember the slogan from an old TV campaign in the States, "Only YOU can prevent forest fires !". Well, here I would say "Only YOU can decide about format size".