The size difference, concretely
A 35mm frame is 24×36mm. A 6x4.5 frame is roughly 56×42mm, 6x6 is 56×56mm, and 6x7 is about 56×70mm.
That means a 6x7 negative has somewhere near four times the surface area of 35mm. Everything else follows from that number.
Four times the area means grain appears at a quarter the relative size when enlarged to the same print, so 400 speed medium format film looks finer-grained than 100 speed 35mm.
It also means fewer frames per roll: sixteen on 6x4.5, twelve on 6x6, ten on 6x7. That constraint shapes how you shoot more than any technical characteristic.
What you actually see in the photographs
Tonality is the difference people notice first and struggle to describe. More area means smoother gradation — skies and skin transition more gradually, and the image holds together at sizes where 35mm starts to break down.
Shallower depth of field at equivalent framing. To fill the frame the same way you use a longer lens or stand closer, so backgrounds fall away more. This is the medium format look people recognise without knowing why.
Detail, obviously, though this matters less than it sounds unless you print large. At web sizes and in a feed, a good 35mm scan and a good medium format scan look far more similar than the negative sizes suggest.
Which is worth saying plainly: if your photographs live online, the quality argument is the weakest reason to switch.
What it costs, per frame
A roll of 120 costs roughly the same as a roll of 35mm and gives you ten to sixteen frames instead of thirty-six. Development costs about the same per roll. So the per-photograph cost is somewhere around three to four times higher.
For someone shooting a roll a month that's the price of a coffee. For someone shooting a roll a week it's a real line item, and it's the reason plenty of photographers own a medium format camera and shoot it rarely.
Cameras themselves are less of a barrier than people expect. A Bronica or a Mamiya 645 can be had for a fraction of what a comparable 35mm system from the same era costs, because demand is lower.
The exception is anything with a Hasselblad or Rolleiflex badge, where you're paying for the name as much as the optics.
How it changes the way you shoot
Ten frames per roll changes everything. You stop shooting variations and start deciding before you press the shutter, because there's no bracketing your way out of an uncertain composition.
Most people find this improves their photographs, and it's the reason many photographers describe medium format as the thing that made them better rather than the thing that made their files bigger.
It also makes you slower. Larger cameras, waist-level finders, manual everything, and a roll change every ten frames. That suits landscape and portraiture and suits street photography and events poorly.
If you like shooting fast and editing down afterwards, medium format will frustrate you regardless of how good the negatives are.
Reasons to stay on 35mm
You shoot moving subjects, or in changing light, or anywhere you need thirty-six frames without stopping.
Your photographs live online. The quality gap narrows enormously at screen sizes, and nobody scrolling a feed can tell.
You're still learning exposure. Cheaper frames mean more of them, and more frames is how you learn.
You already own good 35mm glass. Fast lenses in medium format are expensive and rare; the fastest common medium format lenses are around f/2.8, which is closer to f/1.4 on 35mm in depth-of-field terms than the number suggests.
A sensible way in
If you want to try it without commitment: a Mamiya 645 or a Bronica ETRS. Both are cheap on the second-hand market, both take excellent lenses, and both hold their value if you decide it isn't for you.
6x4.5 is the pragmatic format — sixteen frames per roll rather than ten, and cameras that handle more like a large 35mm SLR than a box you look down into.
A twin-lens reflex like a Yashica Mat is the cheapest route to 6x6 and a genuinely different way of seeing, since you compose looking down at a reversed image.
Shoot five rolls before deciding. The first two will be about learning the camera, and you won't know what you think until after that.
Common questions
Is medium format actually better than 35mm?
It resolves more detail and renders tonality more smoothly, at roughly four times the cost per frame and with far fewer frames per roll. Better for landscape and portraiture, worse for anything fast.
How many photos per roll of 120 film?
Sixteen at 6x4.5, twelve at 6x6, ten at 6x7. Compared with thirty-six on 35mm.
Is medium format worth it if I only post online?
Honestly, less so. The quality gap narrows a great deal at screen sizes. The stronger arguments online are the depth-of-field rendering and the way ten frames per roll changes how you shoot.
What's the cheapest way into medium format?
A Bronica ETRS or Mamiya 645 for 6x4.5, or a Yashica Mat TLR for 6x6. All are affordable second-hand and hold their value reasonably.
Does medium format film cost more?
A roll costs about the same as 35mm but yields a third of the frames, so the cost per photograph is roughly three to four times higher including development.