What is your output size?
Don't go to big
Don't go too small
By the numbers
Subjective calls on the more common rollfilm formats
Worthless trivia

1. What is your output size?

The first and most basic question to ask yourself is what size your finished product will be. This might seem like backwards-thinking, but given the effect of format on cost, it is worth considering.

Despite pretensions at making huge poster-sized prints of their package tours, most people end up getting 4x6 (10x15cm) minilab prints from the drugstore or worse. I see people who subscribe to high-end camera mailing lists talking about getting processing at Costco, for the love of God... It is difficult to square the idea of spending thousands on equipment with the idea of having some yahoo working for subminimum wages cranking the negatives through a dirty roller-transport processor.

Moreover, if a 4x6 is the extent of your enlargements, you will never realize any of the optical qualities of all of those expensive lenses. Although Leica people (even me sometimes) like to think that you can even tell the difference in optical quality between a point-and-shoot and a expensive 35 in minilab prints or on a computer screen, you might be surprised at how often FunSaver camera shots are mistaken for "the real thing." If you never make anything but color prints, and you never make them bigger than 8x10 (or scan to sizes that are viewable on a computer screen), you might as well save yourself a lot of anguish and buy a good 35mm camera. Or even a digital. Medium format is overkill.

2. Don't go too big

First, camera get exponentially more bigger, more expensive and more specialized as their negatives rise in size. When you start with a 35mm film cartridge, you define a minimum size that involves the cartridge, one frame, and a takeup spool. This leads to reasonably compact cameras. When you have to the same with 120, you more than double the height of the film chamber (24mm to 60mm) and the back. This means that the minimum size of a medium format cameras is an inch taller than its 35mm counterparts. Then consider that a normal lens is the diagonal of the film format or longer. So for a 6x9 camera, you need a 100mm lens whose rear element sits almost four inches from the film plane (to say nothing of where the front is).

The expense of cameras also rises superproportionately to size. There is no good explanation for this; it is just a fait accompli.

Then there is the specialization. Medium format cameras break down into several camera styles, all of which have special optimizations. TLRs and SLRs are optimized for portraits; view-camera types are specialized for landscapes, and there are various folders and rangefinders for general use.

Second, film also gets exponentially more expensive and limited as size increases. Por quoi? you ask. Film for 35mm cameras is the most common on the planet. Most films give a minimum of 24 shots per roll. By contrast, a roll of medium format that costs the same amount will yield 15-16 shots (6x4.5), 12 shots (6x6), 10 shots (6x7), 8 (6x9), 7 (6x10) and 4 (6x18). For a 6x9 camera, each shot may end up costing 40 cents. While you can always tell yourself that film is the cheapest part of the process, it really starts adding up. When you hit 4x5 sheet film, you can easily top $1 a frame; not exactly economical, especially when you bracket. Then consider that 35mm has a much wider variety of film available.

Third, the general rule is that the bigger the format, the tougher the processing. Many labs won't go bigger than 35mm; a lot of pro labs stop at 6x7 and won't machine-print 6x9 negatives. When you are doing your own enlarging, it is difficult to overstate just how much more expensive new enlargers get when the mask size exceeds 6x6cm. There are few current 6x7 enlargers. 6x9 enlargers have been co-opted by 4x5 enlargers, which are both huge and expensive. Your best bet in larger 120 formats is to find an old Durst 6.5x9 or an M805.

Fourth, 35mm lenses are shorter and faster, enhancing your chances of getting the shot. Shorter lenses have greater depth of field. They can also be much faster. It is fair to say that you can use film that is four times the speed in medium format, but 120 has few films with speeds over 400.

Finally, scanning 120 negatives is tough - you can either use a flatbed (which is tough, considering that most transparency adapters are for 35mm filmstrips) or shell out $2,000 plus for a medium-format scanner. The cheaper MF scanners (like the Minolta Dimage Multi II) don't deliver the resolution, and their end scans contain little more information than 35mm scans.

3. Don't go too small

Before you think that the discussion above validates your choice of 35mm without qualification, understand that small formats have serious limitations.

First, 35mm cameras cannot deliver as much detail. While 35mm cameras can deliver adequate definition to show small objects in a frame given high-quality lenses and fine-grain film, optical and film limitations still prevent these cameras from showing detail, which Mortensen describes as "the difference in the reflection from silk and from velvet, between the highlight on an egg and on porcelain, between the shadows of wood and flesh." (Mortensen on the Negative, 1946).

The riposte is coming, I'm sure, from people who will argue that some 35mm cameras can rival medium format. This contention is usually based on some combination of a lens' high-frequency MTH (@ 40lp/mm) and the use of some ultra-high resolution film (Tech Pan, Gigabit, whatever). In the real world, these claims are highly dubious.

MTF is Not Determinative

— MTF is an entirely theoretical measure of performance. It is measured without a camera body and without film. Film and ultimate ourput are significant limiting factors. Since resolution of the weakest link in the optical chain brings the whole system down, the 120lp/mm claimed for some high-end 35mm lenses will never be achieved in the real world. Some have computed that even under the best conditions, 60lp/mm is the practical limit due to factors such as film and/or enlargement. By some estimates, scanning cannot reproduce more than 40lp/mm. Since both 35mm and MF lenses can hit these very low targets, it is questionable whether starting with twice this resolution makes any palpable difference.

— MTF and film resolving power is measured using 1000:1 contrast ratios. While this may bear some relationship to shooting newspaper pages, it does no bear any relationship to normal longscale scenes. Sometime you have a free minute, pull a spec sheet for your film and see what the resolving power of your film is with a more normal 1.6:1 contrast range. Not as good as you think.

— Power to record and deliver detail does not automatically follow from high-frequency MTF. Having high MTH in the high-frequency range only tells you that a lens can record a relatively large difference between a black line and an adjacent white line, i.e, it is a measure of potential. It tells you nothing about how a lens differentiates two greys. The high-enlargment factor for a 35mm negative in the output stage degrades the tonality between adjacent greys (see below). Since many of the aspects of texture are dependent on rendition of grey-to-grey contrast (real-world objects are not renderable solely as Zone 0 and Zone 9), high-frequency MTF cannot be considered a be-all-and-end-all.

High Resolution Film Does Not Produce Equal Results

— High-resolution films like Tech Pan and Gigabit are sorely lacking in acutance, which makes the resulting frames look flat, lifeless and less-sharp. I am still waiting to see the Tech Pan landscape that does not look mushy.

— High-resolution films have poor tonal rendition, unless shot (with a tripod) and developed under excruciatingly precise conditions. Then they have fair-to-poor tonal rendition. Neither Tech-Pan nor Gigabit were developed with long-scale scenes in mind. They are document and microscopy films. Remember, Tech Pan replaced a number of other films, including Solar Flare Patrol film.

— High-resolution films have far less room for tone manipulation, which is often needed to produce aesthetically-pleasing prints. This stems partially from the fact that you only typically have one developer usable for each.

Enlargement Kills (and So Does Detail)

— From a practical standpoint, a 6x9 MF lens need only be half as good as the 35mm lens you are comparing it to, since it is only enlarged half as much. Indications are (from sites such as Robert Monaghan's, for example), that medium-format lenses up to 6x9 can have upwards of 80% of the resolution (in lp/mm) that the best 35mm lenses have (and equal or exceed that of run-of-the-mill 35mm lenses).

Consider that the theoretical system resolution of an optical system is defined as the reciprocal of the sum of the reciprocals of the lp/mm resolutions of each element.

R = 1/(1/L + 1/F + 1/O)

Where R= theoretical resolution; L=lens resolution; F=film (or digicam sensor) resolutionl and O=output resolution (enlarger lens or film scanner). You can of course add as many stages as you want. I am not including enlarging paper, because it is not always the final output, and its resolution is much higher than the 6lp/mm required for a normal print at normal distance. Perhaps more pragmatically, I can't find any good numbers on paper resolution. For your reference, a 4000 dpi scanner (if not interpolated) generates 55lp/mm. This assumes that every element is used correctly: for example, the lens is focused exactly; the film is flat; and the output is focused. These can be big "ifs," but as long as we are in the realm of theory...

Plugging numbers in, you see that:

— Assuming you have a 120lp/mm Leica "ubercron," a 120 lp/mm film (Techpan) and a 120lp/mm APO-Componon. Your theoretical limit is 40lp/mm. And this is using perfect technique on a less-than-forgiving film.

— Using a (relatively) mediocre 60lp/mm MF lens, a 50lp/mm film (T-Max 400), and the same Componon, you get 22lp/mm. The difference is that even from 6x4.5, you only need 60-64% of the enlargment (depending on your crop). At 6x4.5, you break even on resolution, even with a high-speed film, against the best 35mm can offer. With 6x9, you need 44% of the magnification (2:3 aspect print), pulling you ahead of even the best 35mm systems (lens/film/output) ever made.

Don't lose sight of two things: (1) the fact that with a 35mm lens, you are creating the target resolution over a relatively small area; in MF it is a lower resolution over a large area; and (2) films only support a certain enlargment range before the grain structure falls apart; Tri-X, for example, will do 2-4x on paper before showing a ton of grain.

— Enlargement degrades tonal rendition, with the more enlargement meaning more degradation. Part of this is due to the fact that the projected image is passing through more air.

— When you are working with landscapes or nearby textured objects, the smallest thing that can be reproduced on film must be at least the size of two grains of silver halide. Your chances of achieving this for a given film type, whether it be branches of a distant tree, or the weave in a 100-thread-count shirt, are far better in medium-format than on 35mm film.

Ultimately, whether 35mm will be better will hinge on your application, but high-resolution film should not present a significant consideration in the decision.

Second, there is a direct relationship between negative size and tonal quality for black-and-white work. Less enlargement yields smoother tones. The 35mm to 6x4.5 step provides the biggest single improvement in tonality. There is also some improvement with color negative materials, but it is not as striking.

Third, there is a direct relationship between negative size and grain. This relationship holds as the negatives get bigger, until you hit 6x7. At that point, you are not going to see any grain on a normal-sized print. The 35mm to 6x4.5 step provides the biggest single improvement in grain size, allowing you to process Tri-X at N+2 with no objectionable grain. Color film exhibits less grain in medium format, but grain is less of an issue with color film in general.

Finally, larger formats are far less sensitive to negative damage. The more enlargement you need, the greater the effect of scratches and dust on or in the negative.

4. By the numbers

The tables below show the particulars for a number of small, medium and large-format films, including the enlargement factors required to reach borderless enlargements. One thing that is interesting about a chart like this is that there are diminishing marginal returns associated with going larger than 6x7, especially if your end-product is a borderless 8x10. For that type of print, your 6x8, 6x9 or 6x10 camera may as well be a 6x7. On the other hand, with A4 paper, the 6x9 has a significant advantage, needing magnification and less cropping than 6x7. The way you can see when you are going to have this cropping is when you read down an enlargement-factor column and see that the factors remain more-or-less constant. The bottom line to all of this is that the best use of your full-frame shots will occur when the aspect ratio of the film is most similar to that of the paper.

5. Subjective calls on the more common rollfilm formats.

	Half-frame 35mm originally began its life as the size of a frame on 35mm movie film. Because it demands a high degree of enlargement, this format taxes film heavily. Fortunately, because the lenses are much shorter (their enhanced DOF helps), focusing errors are less problematic than they would seem. The premier half-frame camera is the Olympus Pen FT SLR, which came with top-flight lenses and a TTL exposure meter. Half-frame has not been rendered irrelevant by digital; half-frame still carries more data, and the Pen line has fast, compact wide-angles (the 20mm is equivalent to a 24mm full-frame lens), something that digital is a little behind on. Grab your scanner!
	So much ink has been spilled on 35mm full-frame cameras, that they do not warrant much discussion here. The 35mm format dates back to about 1915, when someone (it's disputed who) decided to use a frame the size of two cine film frames. The one thing that 35mm has over all larger formats is the sheer selection of film types and speeds. Picks: Just about any quality SLR or rangefinder camera can take good pictures. You might even look at luxo point-and-shoots like the Hexar AF, the Contax T series, the Ricoh GR-1 and the Nikon 35Ti. Pans: Avoid anything with scale focus. 35mm is relatively unforgiving, and cameras capable of focusing with reflex viewing or rangefinders are common and inexpensive.
	The 6x4.5 format falls within the greater 120 family. "Brownie" film has existed since the 1890s and has a paper backing that runs the entire length of the film. The 6x4.5, which is half-frame brownie format appears to have made its entrance with the Zeiss Ikon model 521 Ikonta and the model 530 Super Ikonta A (1930s). When that camera came out, there were no numbers printed on the backing for 6x4.5 frames. You had two red windows. For shot one, you advanced the 1 to the first window. For frame 2, you advanced 1 to the second window, etc. Later Super Ikonta As (531) had a single red window in the back. Picks: I am very partial to the alpha and omega of this format, those being the Zeiss Super Ikonta A (531) and the Fuji GA645 series. The former is small, well-built, all-mechanical and capable of taking great pictures. The latter is a little bigger, but is still compact, has auto and manual exposure modes, autofocus, and data capability. If you want to go in-between, you can get a Fuji GS645, which is a mechanical folder like the Super Ikonta, but with a coupled light meter. Interesting: One interesting variant of the 6x4.5 format is the Rolleiflex T, which can be converted to 16 frames (horizontal) of 6x4.5 from its native 6x6 format. Pans: The 6x4.5 SLRs are almost as big as the 6x6 SLRs and cost almost as much. They beg the question of why. A lot of pros like them. And then there's the Holga.
	The 6x6 format, another Brownie family member, appears to have been the invention of either Franke & Heidecke or Zeiss-Ikon in the 1930s. It did not gain wide acceptance as an American press format until the 1950s and 1960s. The square format, seen in virrtually all twin-lens reflexes (like the Rolleiflex, Autocord), some folding rangefinders, professional SLRs, and even the Century Graphic, obviates the need to rotate the camera to take verticals and horizontals. The downside is that if you don't see in square compositions or you don't like to print on square paper, you will need to crop to print on rectangular paper. In this circumstance, 6x6 offers no real advantage over 6x4.5 and in fact cheats you out of 4 extra frames of film per roll. Picks: Two of my favorite 6x6 cameras are the Rolleiflex TLRs and the Super Ikonta B, a coupled, one-window folding rangefinder. The Minolta Autocord is a real sleeper in this format. Interesting: The Hasselblad SLRs have the best range of lenses and accessories for full-line shooting, but they are big and noisy. Pans: I haven't really come across any bad 6x6, except maybe doing 6x6 on a Century Graphic, because it's a little bit of overkill. I would probably avoid Seagulls, Lubitels and other new cheapo TLRs, if only because much better TLRs like Rolleis, Autocords and Yashica 124Gs are available for not much more.
	The 6x7 format ("ideal format") is a relative latecomer to the 120 scene, not emerging until the 1950s. At that point, the standard press film was 4x5, which could be made to operate quickly, but required a darkroom to load. The 4x5 had an attractive aspect ratio for 8x10 prints, and the Simmons Brothers figured out that the same format could be attained on 120 film by stretching a 6x6 negative. The product of that became the Koni-Omega, an aerial-camera-style 6x7 rangefinder. The Koni-Omegaflex, a 6x7 TLR, followed. Mamiya quickly picked up this format and made the RB-67. The format quickly caught on with Graflex, which started making them for the Graphic line. Then Pentax came up with its 6x7 SLR, which looked like an overgrown Spotmatic, as did Fuji with its G670. The last camera to join the fray was the Mamiya 7, a 6x7 rangefinder. To me, 6x7 equipment always seemed a little bit bizarre, and I think that the aspect-ratio consideration is better addressed by 6x4.5.
	The 6x9 format is the original "Brownie" format. It bears a reasonable resemblance in size to 2x3 inch sheet film. For the better part of the last century, 6x9 cameras were made in a variety of forms, mostly folding pocket cameras. In the more modern era, 6x9 is limited to small view cameras and rangefinders like the Fuji GW690III. The latter looks a lot like an overgrown Leica. This format has very similar proportions to 35mm, and there are strong arguments to be made in favor of using it for landscape and some portrait work. Picks: Fuji 690 rangefinders have phenomenal image quality. The Century Graphic is amazingly affordable and versatile as a 6x9 camera (or 6x7), and you can use just about any lens you want. The Moskva-5 is a good economy 6x9 option, but you really have to watch it with examples currently coming out of Ukraine; they are really starting to scrape the bottom of the barrel. Interesting: Some of the Linhof Super Technikas are like very high-end versions of the Century Graphic. But they are very, very expensive. Pans: The Super-Ikonta C might have been a nice camera when it came out, but the examples you see of it on the market generally need a lot of work. Even then, the Albada finders don't age as well as they seem to on the A.

6. Worthless trivia

120 Film (#2 Brownie), 135 (modern felt-lipped 35mm cartridges) and 220 film are the only survivors of 36 varieties of Kodak roll films made in this century. There were 35; 101-130; 135, 220, 616, 620 and 828. Kind of lonely. See them all, with the cameras they were released with and their sizes (some monster) here.

Do your old negatives smell like vinegar? Cellulose nitrate films from ye olden days degrade quickly, and the vinegar smell is a byproduct. Modern tri-acetate ("safety") films are less susceptible to this — and less flammable.

Modern 35mm film may have been invented as a format by Leica (there is some dispute), but the modern 35mm film cartridge came out with the Kodak/Nagel Retina. Needless to say, the Leica and Contax 35mm cartridges have pretty much faded away. Good thing that 135 cartridges fit the old Leicas and Contaxes...

Thomas Edison is generally credited as the inventor of the 35mm movie format which became the modern half-frame format and doubled, became the full-frame 35mm format.

Nikon claims to have made its prototype's frame size 24x32mm (7 perforations), to better fit printing paper (probably 8x10). Needless to say, it scrapped 24x32 in favor of 24x34 and then 24x36.

The biggest cine format based on 35mm cine film is Vistavision, which was developed from a Fox Natural Color Camera. John Bishop, head of Paramount's camera and film department modified the camera to a 24x36mm frame, with the film running horizontally, using Leica still camera lenses. The resulting camera was called a "Lazy-8," for its 8 performations. Some films done this way include Vertigo and North by Northwest, The Ten Commandments, Shane and White Christmas. Interestingly, very few projectors were made for showing VistaVision movies; typically, the Vistavision negatives were reduced to standard 35mm cine frames for distribution. The big advantage was that in printing films, going from large to small (rather than contact printing) yielded bright, contrasty, grainless prints for movie houses.

"70mm film" is not that wide. In the movie world, 70mm film is a frame that is 51.6mm wide (maximum) and 23mm tall (maximum). By contrast, 70mm camera film is generally 6x7 format. "70mm" refers to the width of the film with perforations.