A Mini Hasselblad in the Making: Building a Hybrid EVF Camera

Blending vintage charm with modern tech, I’m pairing a Mamiya TLR prism with a Raspberry Pi 5 and a one-inch Sony sensor to create a bright EVF with focus peaking.

Merging Old and New

One of the things I’ve wanted to build for a while is a camera with a bright EVF and manual focus assistance. After some tinkering, I think I’ve finally come up with something that works—and it’s starting to look like a mini Hasselblad.

What I’m Working With

• Classic Mamiya TLR prism viewfinder

• Raspberry Pi 5

• Sony IMX283 one-inch sensor

• 800 × 480 HDMI display

• Geekworm X1200 battery

• 3D-printed housing

The concept is simple: use the HDMI display as an EVF and pair it with the prism viewfinder to create a bright, optical-style viewing experience.

Solving the Prism Flip

One challenge with this setup is that the prism flips the image, so the preview has to be reversed and mirrored to appear correctly. I’ve solved this with a Python script using OpenCV and Picamera2 to process the live feed in real time.

Manual Focus Made Easy

For manual focusing, I’ve integrated focus peaking via OpenCV. It highlights the in-focus edges in the frame, making it much easier to nail focus without relying on guesswork.

Proof of Concept

Right now, everything works—the electronics, the display, and the focus assist. All that’s left is to finish designing the body and the mounting points. I’ve done a quick-and-dirty 3D print just to validate the idea before moving on to the final build.

Coming Soon for Paid Subscribers

If you’re a paid subscriber, you’ll get early access to the full Python code I’m using for this build. I’ll also be releasing the final STL files once the body is complete so you can print your own.

Stay tuned—this is just the beginning.

— Malcolm

Camera Code