35mm vs 120 Film: Negative Size, Cost per Shot and Which to Pick

35mm and 135 are the same film. 35mm is the width of the strip; 135 is the catalog number Kodak gave its daylight-loading cassette in 1934, according to The Darkroom. Any camera sold as a 35mm camera takes 135 film.

120 is a roll-film spec, not a measurement. Kodak introduced it in 1901 for the Brownie No. 2, and Hasselblad notes the number says nothing about the film's width or the shape of the photo. The film is about 61.5 mm wide, so '120mm film' is a misnomer.

Medium format means any film bigger than 35mm and smaller than 4x5 sheet film. The Darkroom says 120 is the only medium format roll film still in regular production, so in practice 'medium format film' almost always means 120.

35mm overtook 120 in popularity by the late 1960s, and The Darkroom says it is still by far the most common format, with 120 second. Both are in full production from Kodak, Ilford, Fujifilm, Lomography and others.

It depends on the camera, because 120 film has no fixed frame size. Every 120 frame is about 56 mm tall, and the camera decides how long each one is: a 6x4.5 camera fits 15 or 16 frames on a roll, a 6x9 only 8. That is why sources quote such different ratios. Wikipedia says medium format is 2 to 6 times the size of 35mm, and The Darkroom says 3 to 4 times on one page and 3 to 5 times on another.

Doing the math with Wikipedia's actual frame sizes against a 35mm frame of 864 sq mm settles it: 6x4.5 is about 2.7 times the area, 6x6 about 3.6 times, 6x7 about 4.5 times and 6x9 about 5.4 times. Half-frame 35mm goes the other way, with half the area of a normal frame.

You pick the frame size when you pick the camera. The film is identical, and the backing paper carries three rows of frame numbers, for 6x4.5, 6x6 and 6x9, that older cameras show through a red window.

6x4.5 (645) gives the most frames, 15 or 16, and is the smallest and least expensive 120 size. Cameras range from the Fujifilm GA645, an autofocus point-and-shoot, to the Mamiya 645 system. At about 2.7 times the area of 35mm, it splits opinion on Fstoppers: one commenter calls 645 barely medium format next to 6x6, 6x7 or 6x9, while another says it holds as much usable film area as 6x6 in a 4:5 print.

6x6 gives 12 square frames. 6x7 gives 10 frames and enlarges almost exactly to 8x10 inch paper, which is why Wikipedia says its fans call it the ideal format. 6x9 gives 8 frames with the same 2:3 shape as 35mm.

Per roll, often not. Per frame, yes. Ilford HP5 Plus is $10.79 in both formats at Film Developing Co in Eau Claire, Wisconsin, and Kodak Portra 400 works out to $14.80 a roll in 120 against $16.00 in 35mm at the Film Photography Project store. But a 120 roll holds 8 to 16 frames instead of 36, so each shot costs about 2 to 3.6 times as much at 6x4.5 to 6x7. Hasselblad says the same: cost per photo is generally higher on 120.

Add developing and the gap stays. With Portra 400 and The Darkroom's $14 develop and scan, 35mm comes to $16.00 + $14 = $30.00 for 36 frames, about $0.83 each; 120 at 6x6 comes to $14.80 + $14 = $28.80 for 12 frames, about $2.40 each, before shipping. To run the numbers for your own film and lab, use the film cost per photo calculator.

At the US mail-in labs we checked, 120 costs about the same to develop as 35mm, within a dollar or two. The Darkroom in San Clemente, California charges $14 to develop and scan either format. Richard Photo Lab in Santa Clarita, California charges $10 develop-only for both, and its Noritsu process-and-scan starts at $23.98 for 135 and $21.98 for 120. Boutique Film Lab in Nashville charges $6 for C-41 process-only on 35mm and $7 on 120, and $17 versus $13 for processing plus a set of 4x6 prints, where a 120 roll has fewer frames to print (prices checked October 2026).

Everpresent says labs charge more for 120 and that not every lab takes it, so check before you send. The real limit is drop-off: The Darkroom says most drugstore and big-box photo counters don't accept 120 at all or send it to an outside lab. See our guides to CVS, Walgreens and Walmart developing and the best mail-in film labs.

On the same film stock, the grain is the same size; you just see less of it. Grain per square inch is the same on 120 and 35mm, Analogue Wonderland explains, but because the whole image is bigger, the grain is less noticeable. Hasselblad puts it the other way around: a larger negative needs less enlargement to make a print of the same size. That is why guides such as Everpresent and Club 35 simply say 120 has finer grain.

Print size is where the difference shows. A 35mm negative needs about 8x magnification for an 8x10 print, as one Fstoppers commenter puts it, while a 6x7 negative fits 8x10 paper almost exactly. At small sizes the gap narrows: a member of The Photo Forum says 8x10 prints from 35mm and 6x7 may show no difference in perceived sharpness, yet the prints still look different.

There is no agreed number. Shotkit's chart puts 35mm at about 20 MP and 120 at about 80 MP (60 MP for 6x6, 120 MP for 6x9). PictureCorrect estimates 20 to 22 MP for high-end 35mm but 10 to 14 MP for an average 35mm photo, and says medium format often rivals or beats 40 to 50 MP digital cameras.

In practice, the scan decides your file size, and lab scans can flip the order. The Darkroom's super scan is 4492 x 6774 pixels for 35mm (about 30 MP) but 3533 x 4824 for 6x4.5 (about 17 MP), and a Noritsu HS-1800 lab scanner gives 30.4 MP for a 35mm frame versus 17 MP for 645. Club 35 notes that 35mm may need a 4,000 ppi scan to match the pixel size of a 120 scan at 2,000 ppi. If resolution matters, ask your lab for the pixel dimensions of each format before you order.

Yes, at the same framing and f-number. A bigger negative needs a longer lens to show the same view, and Hasselblad explains that the longer lens can then give shallower depth of field. Wikipedia lists typical normal lenses of 40, 50 or 55 mm on 35mm, 75 mm on 6x4.5, 80 mm on 6x6 and 90 mm on 6x7.

Medium format lenses are generally slower than 35mm lenses, but Fstoppers notes some still give depth of field like an f/1.2 to f/1.4 lens on 35mm.

K1000

35mm covers nearly every SLR and point-and-shoot, from the Canon AE-1 and Pentax K1000 to the Olympus Stylus, plus disposable cameras and the Kodak Ektar H35, a half-frame camera that can double the shots per roll.

120 cameras run from the Holga 120N and Diana F+ to Rolleiflex and Yashica twin-lens reflexes, the Hasselblad 500 series, Mamiya RB67, RZ67 and 645, and the Pentax 67. The big systems are heavy: Club 35 lists the Mamiya RB67 at 2.8 kg (about 6.2 lb) and the Hasselblad 500C/M at 2.2 kg (about 4.9 lb), against 590 g (about 1.3 lb) for a Leica MP. Many of them take interchangeable film backs, so you can switch film stocks mid-roll.

For speed and portability, Long Weekend says 35mm wins, with smaller kits and quicker handling, while 120 rigs are slower, heavier and better for deliberate shooting. Is 120 too slow for events? Its writer says not necessarily: plenty of wedding and portrait pros use 6x4.5 or 6x7, as long as you plan your pace and bring extra backs or rolls.

Handling the film differs too. 120 has no metal cartridge, only backing paper wound on a spool, so it is never rewound: roll-film cameras have a winding knob but no rewind knob, and the empty spool becomes the take-up spool for the next roll.

Yes, in simple box cameras like the Holga. The Film Photography Project sells a 35mm to 120 adapter kit for $29.99 (October 2026) that lets you load a 35mm cassette in a 120 camera, so the image runs across the sprocket holes for a panoramic look.

Frames come out about 3.5 x 6 cm in a 6x6 camera, 3.5 x 7 cm in 6x7 and 3.5 x 9 cm in 6x9. The store says the adapters won't work in cameras with more involved loading, such as the Fuji GA645, Mamiya 645, Mamiya 7 or RB67.