The Mamiya 645J is the budget version of the original Mamiya 645 from 1975. It is small, well-built, takes lovely glass, and gives you 16 frames of 6x4.5 per 120 roll. I genuinely liked using it.
I eventually sold it on. Not because there is anything wrong with it (there is not) but because I subsequently bought a Bronica ETRS and decided I did not need two 6x4.5 cameras in my collection. Between the two, the Bronica won for me. Other people will reasonably make the opposite choice.
This article is an honest review of the Mamiya 645J, the lessons I learned about buying cameras with “lens broken” listed as a fault, and the comparison with the Bronica ETRS that came later.
If you are considering a Mamiya 645 system and trying to decide between the various versions, or if you are weighing it against the Bronica ETRS, this article has my views on both questions.
What it is
The Mamiya 645J is a 6x4.5 medium format SLR shooting 16 frames per 120 roll, made by Mamiya from 1979. It is the budget stripped-down version of the original Mamiya 645 (1975) and 645 1000s (1976).
A few key technical points.
Electronically controlled shutter, battery required. Even the very first Mamiya 645 from 1975 had this. Without a battery, the camera does nothing. The battery is small, standard, and easy to find. But you absolutely need one.
No interchangeable back. Unlike many medium format SLRs, including the Bronica ETRS, the Mamiya 645J has a fixed back. You push a tab, the back opens, and there is a removable film insert that you load film into. Put the insert back, close the back, wind on, go. This is one of the J’s budget compromises. The more expensive Mamiya 645 models have full interchangeable backs.
The Mamiya Sekor C 80mm f/2.8 is the standard lens that comes with most J examples. Mine has this lens. The Mamiya glass reputation is justified. These are excellent lenses by any standard.
No autofocus. Manual focus only, which is correct for a 1979 camera but worth knowing.
TTL metering via the prism finder. This is where the interesting design feature lives. More on that below.
![PLACEHOLDER: the Mamiya 645J with the metered prism and the 80mm f/2.8 Sekor C, showing the compact form factor]
The Mamiya 645 lineage, briefly
Worth knowing because there are a lot of these and they are easily confused.
First generation (1975-1985):
- Mamiya 645 (1975): the original
- Mamiya 645 1000s (1976): adds 1/1000th shutter speed
- Mamiya 645J (1979): budget version, fewer features
Second generation (1985 onwards):
- Mamiya 645 Super (1985): major redesign
- Mamiya 645 Pro (1993)
- Mamiya 645 Pro TL (1997)
- Mamiya 645E (2000): simplified again
Autofocus generation (1999 onwards):
- Mamiya 645 AFD and successors
This article is specifically about the 645J. The other models are different enough cameras that my findings here do not transfer wholesale. If you are looking at a Mamiya 645 Super or Pro, my views below may not apply.
The clever TTL metering linkage
This is the design detail I want to flag because it is genuinely interesting and many reviews skip over it.
The Mamiya 645J’s prism finder has a built-in light meter, but the camera itself has manual exposure control. How does the meter know what aperture you have set on the lens?
Mamiya solved this with a mechanical linkage that converts your physical aperture setting into an electronic signal sent to the meter. Look at the lens: there is a small tab that moves as you change aperture. The prism has a corresponding notch that engages with that tab. As you turn the aperture ring, the tab moves the notch, which moves an internal mechanism that tells the meter what aperture you are using.
This is very similar to the “bunny ears” linkage on the Nikon F2 of the same era: a mechanical solution to the problem of getting aperture data into an electronic meter before the days of fully integrated electronic lens contacts.
The result: you set your ISO on the camera, the camera knows your aperture via the linkage, the meter reads the light through the lens, and it gives you a recommended shutter speed. You set the shutter speed manually and shoot.
This is not auto exposure. The camera does not change anything for you. But the meter is properly TTL through the actual taking lens, with the actual aperture you have set. It is centre-weighted but accurate.
I had not seen this linkage approach in a medium format camera before. It is a clever bit of engineering and it makes the camera surprisingly pleasant to use as a meter-by-meter shooter.
The “lens is broken” lesson
I want to be honest about something I did wrong on this purchase.
I bought this Mamiya 645J cheap because the lens was listed as broken. I had a strong suspicion about what “broken” actually meant on a Mamiya 645 lens (because this is a very common failure mode for these), and I gambled that I could fix it.
I was right about the diagnosis. Someone had previously gone in and oiled the aperture blades.
This is a mistake that is much more common than people realise. Aperture blades are not supposed to be oiled. They are dry mechanisms that move against each other on precisely-engineered pivots. When the blades start to slow down or stick (as they will on old lenses), the correct fix is to clean them properly, removing accumulated dust and debris. Oil makes everything worse.
What happens when you oil aperture blades: the surface tension of the oil between the overlapping blades stops them moving. The blades become essentially welded together by capillary action. They stick wide open and refuse to close. The “lens is broken” listing on eBay is born.
The proper fix is to disassemble the lens, clean the blades thoroughly with appropriate solvents, and reassemble with no oil at all. This is a job for someone who knows what they are doing. It is not a job for someone who is in a hurry.
I was in a hurry.
I gave the aperture blades a partial clean rather than a proper service. I removed the worst of the oil. The blades moved again. I assumed I was sorted. I took the camera out to shoot.
The blades started to slow down again during the shoot. Some of the frames from my morning out with my daughter Cora are slightly overexposed because the aperture was opening more slowly than the metered exposure assumed. This is on me, not on the camera. I cut a corner and it came back to bite me.
For anyone considering buying a Mamiya 645 with a “broken lens” at a bargain price: it is probably an oiled aperture, the fix exists, but do the fix properly the first time. A botched partial service gives you exactly the experience I had: a camera that works for a little while and then stops working again at the worst possible moment.
I have since taken the lens apart properly. It is now sorted.
![PLACEHOLDER: the disassembled lens showing the aperture blades being cleaned properly during the eventual proper service]
The shoot with Cora
Took the camera out for an afternoon walk with my eldest daughter Cora. Two rolls of film: Fuji Pro 400H and Kodak Gold 200.
This was a follow-up to a shoot I had done a month or so earlier with my younger daughter (who appears regularly on the channel). Cora had been a bit jealous of her younger sister’s screen time. Fair enough, older sibling rights.
The shoot was relaxed: walking, talking, occasional camera moments. I let Cora be Cora and tried to catch her doing what she does (drawing, walking, peeking out of an archway).
The Mamiya 645J was a genuine pleasure to use for this kind of work. The weight is balanced. The viewfinder is bright. The metered prism gives you a quick reading without breaking from the moment. The Sekor 80mm f/2.8 produces lovely environmental portraits at wider apertures and respectable depth of field stopped down.
The overexposed frames from the aperture issue did spoil a few results. But the frames where the aperture had moved correctly came out beautifully. The Mamiya glass is the real attraction of this system.
What I liked about it
A summary of what works.
The size is right for medium format. Smaller and lighter than the Bronica S2A by a comfortable margin. Heavier than 35mm but not punishingly so. A good camera for a day’s walk.
The Sekor lens is excellent. Sharp wide open, very sharp stopped down, contrasty without being clinical. This is one of the best-bang-for-buck medium format lenses you can buy.
The TTL metered prism just works. The mechanical aperture linkage is clever and accurate. Quick to operate. Gives you confidence in your exposures.
The handling is comfortable. Controls fall where you expect them. The wind-on lever is smooth. Shutter release has a positive feel.
The build quality is solid for a “budget” model. This is a budget Mamiya, not a budget camera. The build is properly engineered. The materials feel right.
What I did not like
To be fair to the camera, the things I did not like are mostly J-specific compromises rather than Mamiya 645 system issues.
No interchangeable back. You cannot swap film mid-roll or carry pre-loaded backs. For my style of shooting this rarely matters, but for some workflows it is a real limitation. The Mamiya 645 Super and later models fix this.
Battery dependence. Without a working battery the camera is a paperweight. Carry spares. Standard for electronically controlled cameras of this era.
Slightly slow flash sync. A focal plane shutter camera has its limits on flash sync speed, and the J is no exception. Around 1/60th. Limits the kind of fill flash work you can do.
The viewfinder is bright but not bright enough. Compared to some other medium format SLRs (the Bronica ETRS is similar, the Rolleiflex SLX is better), the Mamiya 645J’s viewfinder feels slightly dim, especially in low light.
How it compares to the Bronica ETRS
This is the comparison most people are looking at, so worth addressing directly. The full Bronica review is in the dedicated ETRS article, but for context here:
Mamiya 645J vs Bronica ETRS:
- Lens quality: roughly comparable. Both manufacturers produced excellent glass.
- Handling: the Bronica wins for me, narrowly. The controls fall slightly better, the body shape suits my hands better.
- Build quality: the ETRS feels genuinely solid in a way the J does not quite match (although the J is still well-built).
- Lens ecosystem: Bronica has the edge. The ETR/ETRS/ETRSi lens range is larger and more varied.
- Flash sync: Bronica wins. Leaf shutter in the lens means flash sync at all speeds, vs the Mamiya’s 1/60th focal plane sync.
- Removable backs: Bronica wins. Interchangeable backs are useful.
- Price: the Mamiya 645J is generally cheaper on the used market than an equivalent-condition ETRS.
For my use case the Bronica is the better camera. But the Mamiya 645J is genuinely competitive and someone who specifically wants a budget 645 system, particularly someone coming from 35mm and looking for their first medium format, could very reasonably prefer the Mamiya.
This is not a “one is better” verdict so much as a “they are both excellent and suit slightly different photographers” one.
Why I sold it on
Honesty time. I am keeping the Bronica ETRS. I sold the Mamiya 645J.
The reasons are mostly personal preference rather than objective. The Bronica handles slightly better for me. The leaf shutter flash sync matters for the work I want to do. The lens ecosystem is broader. I have other Bronica cameras and lens accessories that cross over with the ETRS system, which makes a unified Bronica kit more economical than a split Bronica-plus-Mamiya kit.
If I were starting fresh with no other cameras and choosing between these two specifically, I would probably still pick the Bronica. But it would be closer than the actual choice was for me.
The Mamiya is now somebody else’s camera. They are probably very happy with it.
Verdict
A genuinely good camera that I would recommend to anyone wanting an affordable entry into medium format.
Buy it if:
- You want a budget medium format SLR with excellent lenses
- You are coming from 35mm and want a rectangular frame transition
- You will not miss interchangeable backs
- You can find a clean example or are prepared to fix common issues (oiled apertures, light seals)
- You prefer the Mamiya handling to the Bronica handling (try both before committing if possible)
Skip it if:
- You specifically need flash sync at all speeds (look at the Bronica ETRS)
- You want interchangeable backs (look at the Mamiya 645 Super or Pro, or the Bronica)
- You are sensitive to viewfinder brightness (the J is workable but not exceptional)
- You hate dealing with old lenses that might need servicing
The Mamiya 645J is an excellent budget medium format camera. I liked using it. I learned about oiled apertures. I sold it because I prefer the Bronica ETRS. None of those statements contradict each other.
If you have a Mamiya 645 (any variant) and want to share your experience, I would love to hear from you in the comments. Particularly curious about how the later models (Super, Pro) compare to the original J.