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BUILD A MEDIUM FORMAT CAMERA FROM AN OLD PRO BACK

The Phase One P45+ medium format back had an indicative price of 32,990 dollars when new. Used ones now turn up for 500 to 800 dollars, and a simple 3D printed body pairs one with a 50 dollar Mamiya Press lens.

by snappiness

FULL CAD BOM FIRMWARE DOCS

Workshop

Built with3D printing

difficulty
●●●○○
time
a weekend
license
license not specified
repo
repo ACTIVE0 stars

WHAT YOU’LL NEED

Videos
1
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COMPAREE VERDICT

This is a version-one 3D printed body that mounts a medium format digital back on a Mamiya Press lens. The lens itself is about 50 dollars; the back is the expensive part. The Phase One P45+ is a 39 megapixel CCD back from 2007 with a 49.1 by 36.8 mm sensor, more than twice the area of full frame, and the creator consistently finds working units for 500 to 800 dollars used (some still sell for over 1,000). The one thing most likely to go wrong: the flange distance is off, so the camera does not focus to infinity. The printed latch that holds the heavy back works, but only just; the back sometimes slides out by a millimetre, which throws off focus, so he holds it against the body. There is no live view: you shoot, check the back's screen, and adjust, using the lens focusing scale. Indoors the results looked good apart from heavy noise at high ISO; outdoors he got harsh contrast and odd results he could not explain yet. This is for someone who wants to experiment with medium format on a budget and can work from the models and the video.

GOOD TO KNOW

  • —The 3D models are free on Thingiverse (thing:7196063). Check the licence on the Thingiverse page before reusing them.
  • —Hardware mentioned in the video: brass heat-set inserts and a small spring from Amazon (about 5 dollars); no sizes are given in the video.
  • —No written assembly guide in the video; it shows the build and the known issues: weak latch and no infinity focus.
  • —The creator calls this version one and asks whether viewers want a V2 that fixes the issues.
  • —You supply the digital back (his is a Phase One P45+ in Hasselblad H mount), a Mamiya Press lens and a sync cable.
  • —The Mamiya Press lens adapter came from another creator's free 3D model.

Parts to buy

5 items

From our check of the build. Exact quantities and part numbers are in the creator’s BOM.

  • Phase One P45+ in Hasselblad H mount (500-800 dollars used)Find
  • Mamiya Press lens (about 50 dollars)Find
  • Sync cable (about 80 dollars)Find
  • Brass heat-set insertsFind
  • Small spring (about 5 dollars)Find

Can I build this?

PrintCamera body, back latch and Mamiya Press adapter from Thingiverse thing:7196063, plus brass inserts and a small spring.
BuyPhase One P45+ in Hasselblad H mount (500-800 dollars used), Mamiya Press lens (about 50 dollars), sync cable (about 80 dollars), brass heat-set inserts, small spring (about 5 dollars).
Tools3D printer, an insert tool or a cheap soldering iron for the brass inserts.
Skills3D printing and some problem solving; there are no written instructions, so you work from the models and the video.
TimeA weekend if you already have the back and lens.
Cost$$$, dominated by the digital back at 500 to 800 dollars used.
SafetyNone beyond ordinary 3D printing and handling a heavy digital back with care.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

Videos

I Built The Cheapest Possible Medium Format Digital Camera12:19

The creator explains how to pick a cheap digital back, builds the body, shows indoor projector-lit test shots and outdoor tests, and explains the current limits including no infinity focus.

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Gallery

Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Download the 3D models from Thingiverse thing:7196063 (Known issues from the video: the flange distance is off (no infinity focus) and the latch is weak.)
  2. 2.Watch the YouTube video to see how the parts fit together (The video is the guide to how the parts fit together and how the two-shot sync works.)
  3. 3.Source a Phase One P45+ (Hasselblad H mount), a Mamiya Press lens and a sync cable(The back is the expensive part: he finds working P45+ units for 500 to 800 dollars. Pick a back with its own battery and a sync cable you can find.)

Resources

Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.

KNOWN ISSUES

  • The flange distance is off in this version, so the camera does not focus to infinity. Expect to shoot at closer distances until the model is fixed.
  • The printed latch is the weak point. The back is heavy, and the creator handles it very cautiously; it can slide out by a millimetre and shift the focus plane.
  • Old CCD backs like the P45+ have no live view. You compose by guesswork and the lens focusing scale, shoot, then check the back's screen.
  • Outdoor test shots came out with harsh contrast and odd exposure; the creator did not yet know if the cause is the lens, a light leak or the two-shot mode.
  • Check the sync cable before buying a back. Some cables for some backs are expensive or hard to find; his cost about 80 dollars.
  • A remote shutter release jammed his Mamiya Press lens, so he fired by hand, which adds shake.
  • The Mamiya Press lens adapter part is another creator's free model, not his own design.

Can I use a different digital back?

The printed body is built for a back in Hasselblad H mount, which is the version of the P45+ the creator bought. Backs come in several mounts, so a different mount needs its own adapter. He suggests picking a back that runs on its own battery and whose sync cable you can actually find.

Why does it not focus to infinity?

The flange distance, the distance between the lens mount and the sensor, is not quite right in this version. Sources disagree on the Mamiya Press value; he built it to 61.35 mm and says he will need to revisit it.

What is the sensor size advantage?

The P45+ sensor is 49.1 by 36.8 mm, compared to 36 by 24 mm for full frame. That is more than twice the area. It is an old 39 megapixel CCD from 2007, so high ISO is very noisy.

Do I need a sync cable?

Yes. The shutter is in the lens, so the sync cable tells the back when the lens fires. His cable cost about 80 dollars. The back works in a two-shot mode: the first shot wakes it, then you have about 5 seconds to cock the shutter and fire the real exposure.

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Discussion1

FROM THE COMPAREE TEAM

A 39 megapixel medium format sensor for 500 to 800 dollars used, but no infinity focus yet. Would you build this as a close-range camera, or wait for a V2 with the flange distance fixed?

CompareeTEAM1d ago

Practical notes from our verification: the creator calls this version one and is upfront in the video about the known issues: no infinity focus and a latch that only just holds the heavy back. There is no written guide, so you work from the models and the 12-minute video. The single biggest decision is whether you are fine with a camera that does not focus to infinity until the flange distance is fixed. We could not open the Thingiverse page to confirm its licence, so check it before reusing the files.

snappiness

snappiness makes DIY camera builds on YouTube; this is not his first printed camera body. He spent a couple of months researching old digital backs to find the cheapest way to shoot digital medium format.

Star the project on GitHub

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  • Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
  • Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
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