How One Photographer Turned a Cheap Pentax SLR Into a Half-Frame Camera

Last Updated on 07/17/2026 by Chris Gampat

Pentax SLR cameras have been popular for many reasons. They offer a great form factor, are easy to use, and typically very affordable. An example of this is the DIY Pentax camera, which can now shoot half-frames with ease. Here’s a look at how this breakthrough was achieved.

On r/AnalogCommunity, u/wolfix1001 revealed how he converted a Pentax ZX-5n into a fully functioning half-frame camera.

What a Half-Frame Mod Does

In a standard 35mm camera, a half-frame can help one to shoot two smaller frames in one frame. This is usually done so vertically by splitting the scene in half. There are some cameras like the Olympus Pen F and Pentax 17 that people often buy if they want to save up on the cost of film. However, converting a somewhat modern autofocus SLR into a half-frame camera solves that problem. It helps one to get autofocus assistance, even when one is using fully manual lenses.

However, this model has achieved the feat by manipulating the film-advance counter so it only winds the film forward half of a normal frame’s distance between shots. That’s done through a mask and then the film counter has to be modified accordingly.

A Look at The Process

According to the original post, this idea was first pioneered by another Reddit user, r/vandergus, who converted his MZ-3 to shoot half frame. To get this right, u/wolfix1001 worked on five different cameras before finalizing on ZX-5n. A common challenge was the age and fragility of the cameras. The ZX series faced challenges, including a cracked mirror lever, a cracked shutter motor gear, and a cracked pop-up flash pivot due to the plastic components. But ZX-5n, ZX-5, ZX-7, and ZX-L were steadier given that they use metal lens mounts.

To fix the cracked mirror lever, u/wolfix1001 relied on a 3D-printed replacement part, with the STL file available through a linked iFixit repair guide. There was also a brass gear replacement for the shutter motor.

In fact, one can now use APS-C lenses, since the two formats share similar image circle covers. On the ZX-5n specifically, converted shooters are limited to Program and Shutter Priority modes.

However, if one can’t make such a camera, they can buy it from Reflx Labs, which sells already-converted half-frame and even square-frame versions of the Pentax MZ-10, MZ-50, MZ-5, and MZ-7.

Instances such as this prove that photography requires multiple steps. Innovation must go on for one to achieve perfection. And this only helps one to achieve that, without spending money.