120 or 220 film

Why is 220 not used much?

For what it's worth, I use 220 *more* than 120. In fact, the only

time I use 120 is when I know I'm only going to shoot a limited number

of photographs with a given film. For example, if I'm asked to

photograph a wedding in darkish church that doesn't allow flash

photography, I might use 120 roll of NGHII (800) for the ceremony and

use 220 NPH (400) for everything else. It is has always been my

understanding that, for reasons I don't pretend to understand,

220 film "lays" a bit "flatter" than 120 and thus produces a nicer

image. Exactly how much "flatter" it lays, I can't say--probably not

enough to make a real difference but, that is my understanding

nonetheless. I'm not sure exactly where you can to the conclusion

that 220 is used less than 120.

It is a bit of a mystery. Usually a different back is required and not all films come in 220 sizes, so it is a chicken and egg situation. Personally as someone who shoots MF only occasionally the 12 shots on a 120 in some ways is better as you can finish and process the film quicker than having to wait to shoot all 24. On the other hand on an extended shoot then 220 is a must. You have to be a bit more careful with fogging of the edges and in b & W its length is a bit of a pain for processing especially hanging the film up to dry, but anything that reduces the number of film changes you need to do is a good thing.

The only problem with 220 film, is the range of emulsions for B&W is limited. Can't get Delta 100, TMX or Tech Pan in 220. If you like the older emulsions, Tri-x, FP-5, or the 400 t-grain films, then 220 is a good choice. It'd love to get hold of 220 TMX.

Where I live the 220 film is much more expensive per image. It is difficult to say if this is the cause or the consequence of your observation.

From Carl Zeiss Camera Lens News No. 10, Summer 2000

 

Is rollfilm 220 better than 120 in terms of film flatness?

 

Zeiss has recently developed a new measuring system to evaluate film flatness in medium format photography.

 

The new system is based on an computerized microscope that can automatically scan and focus on multiple points of a film frame in a medium format camera magazine. The obtained focusing data are recorded by a computer and evaluated by a propriatory Zeiss software. The result is a mapping of the film topography with an accuracy of one millionth of a meter (1 micron), according to the developer of this system.

 

The purpose of this new device is to find out how well film magazine mechanics are designed in today's medium format camera systems, how precise they position the film and how well they hold it flat. From these findings Zeiss can draw conclusions about the field flatness required for medium format lenses and Zeiss can also trace causes for lack of sharpness in customer's photos. This is particularly interesting since more than 99% of all customer complaints about lacking sharpness in their photos can be attributed to misalignments of critical components in camera, viewfinder, or magazine, focus errors, camera shake and vibrations, film curvature, and other reasons.

 

So far, Zeiss has found that film curvature can have a major influence as a source of unsharpness. This has also been known by Zeiss' camera making partners Alpa, Hasselblad, Kyocera (Contax) and Rollei. Since Zeiss' evaluation program is not completed yet, we would like not to draw too many conclusions prematurely. But two things can be stated already as hints to enable sharper photos with medium format cameras at wide open apertures, since exactly those are invited by the high level of aberration correction in Zeiss lenses:

 

1.

220 type rollfilm usually offers better flatness than 120 type by a factor of almost 2. This is an advantage with fast, motorized cameras like the Contax 645 AF, Hasselblad 555 ELD (and previous motorized Hasselblad cameras) and Rolleiflex 6000 series cameras.

 

2.

Film flatness problems are mainly caused by the combined influence of two factors: the rollers in the camera or magazine that bend the film, and the time a certain part of the film is bent by such a roller.

 

Camera manufacturers usually space the rollers in a way that bent portions of the film will never be positioned near the center of the image. Therefore only marginal regions of the image should be affected by sharpness problems due to film flatness errors.

 

Since the photographer cannot alter the geometry and mechanics of his camera, he can only influence the other factor: time. A film run through the camera without much time between exposures should result in good flatness and hence sharpness. Five minutes between exposures may be some sort of limit, depending on brand and type of film. 15 minutes are likely to show an influence of bending around rollers. Two hours definitively will.

 

As a rule of thumb: For best sharpness in medium format, prefer 220 type roll film and run it through the camera rather quickly.

The fact that 220 film might deliver a better flatness than 120 film is a little strange to me. I though that the additional paper back on

120 film would give a better support to the film and increase the flatness while protecting the film against scratches. Also I supposed

that the paper didn't keep too easily the curvature of the spool and so help for flatness. The Zeiss measurement will probably be an

interesting lecture, but I fear they will only concern cameras that use some Zeiss lenses.

 

I also don't understand why a motorized camera offers better flatness, is it because the film is more tended? I can not believe it has

something to do with the film transport speed. That the time interval between each frame has some influence sounds a little more

logic, but it's also related to the design of the magazine and position of the rollers. And what about the cameras without a magazine

(Pentax 67, Mamiya 7...)? Those cameras do not have rollers that bend the film and the film comes directly out of the spool so there

is no difference in flatness if there is a long time between each frames. Also a camera without magazine, where the film comes out

directly from the spool (like in 35 mm), the film will tend to have a little more pressure in the middle of the frame, and might help the

flatness in this area. In opposite, a magazine design, will have more trouble to keep the film flat in the middle.

 

Even if the film flatness is a concern with wide aperture, teles and macro, I thing that the design of the film transport has at least the

same importance as the choice of 120 and 220 film. For sure, Contax and Linhof (aerotechnika) didn't develop a vacuum back just

for fun.

 

So far my 2 centimes about film flatness.

 

Personally I like the 120 films better, I don't shoot like a machine gun, and many emulsions are not available in 220 format. And

most of the time the 220 is more than twice the price of 120.

 

This might be a long and interesting tread.

 

Colin

If bending the film for even a few minutes effects sharpness,

doesn't this imply that the exposures at the beginning of a roll of

film would be less influenced by the bend from being wrapped

on the spool for months/years prior to use?

 

Even cameras with pressure plates can't keep the film

completely flat, as they hold the film down only at the edges

against the film rails. If the shot is 6x9 or 6x17, one would think

there's a greater chance for the center of the film to bow inwards

or buckle (towards the lens) as compared to 6x4.5 or 6x6. When

you receive your uncut but sleeved 120/220/35mm chromes

back from the lab, ever notice, more than often, they have a warp

in the center running down the length of the entire film?

No wonder I keep getting those unsharp photos. Are we are all on the wrong track with MF? Back to glass. Trouble is that glass is a supercooled liquid and does flow with time. Anyone know of a camera with a motor drive that uses glass slides?

I use 220 WAY more than 120. I only use 120 when I need a film that I cannot get in 220, like tungsten. For one thing, it is much cheaper in 220. While the film costs are almost the same, processing is much cheaper. My lab only charges like $2 more for my 220 rolls over the cost of 120, thus lots cheaper per image. Plus, I hate taking the time to load another roll of film and I like to keep at least one camera body loaded, for instant shots.