CMOUNTIPHONE2 Turns a Cracked iPhone 13 Into a Canon EF Camera Body

Evan Monsma spent a few days in Indianapolis turning a broken iPhone 13 into something he calls CMOUNTIPHONE2, a phone that can take Canon EF lenses meant for a full-size DSLR. His earlier attempt had already put cinema glass on a wrecked iPhone. That mount was wood, a modified C-to-CS ring, and a bead of super glue. The glue let go. A heavier lens was always going to finish the job, so this round starts with metal.

A shop had a unique plate made for him, which is brass and copper in the build video, with holes cut out for two of the back cameras and a clean passage for the third. PCBWay took care of the cutting. The additional plastic around the camera holes prevents stray light and dust from entering. He then painted the inside a dark black to prevent light from bouncing off the exposed metal and onto the sensors, before gluing the plate to the phone back with steel-filled epoxy after roughing up both surfaces. The plates with printed covers fit snugly over the empty holes. A tripod thread was also cut into the bottom of the plate, which dissipates heat far better than the plywood on the initial version.

Getting a usable image out of this thing, however, required much more than just putting on a lens ring. Lenses only really focus when they are at the proper distance from the sensor, which is known as the flange distance. The problem is that an iPhone is so thin that virtually any old mount would fit close enough. CS surveillance lenses just sit straight on the plate. A 5mm spacer then allows C-mount film lenses to fit, and the C-to-EF adapter allows you to experiment with Canon EF glass, which was essentially the goal of the second construction. He then removed the stock lens modules off with sideways force, cleaned the edges, and left the sensors intact. He had previously assumed that every iPhone 13 sensor was the same size, which was incorrect. No, the main camera and the 0.5x wide camera are not the same size, therefore a 16mm lens will not provide the field of view you expected.

When using the iPhone 13’s small sensor, full-frame glass acts as a long lens. According to Monsma, this reduces the image size by four to five times, so a 16-35mm EF zoom seems more like an 80-160mm equivalent, while a 70-200mm reaches up to 500-1000mm. Meanwhile, focusing is done manually, with Monsma utilizing the Blackmagic Camera software to shoot in a 4:3 open-gate mode to make better use of the sensor. However, the period of stabilization has ended. The original mechanism was supported by a couple of delicate phosphor-bronze springs, so removing the front glass or putting some grit in there was enough to send the device wobbling. Handheld video ends up wobbling all over the place. On the other side, employing a tripod helps to keep the long glass steady.

Pink fringing runs down the frame’s edges. Now that the stock cover that blocked some of the light has been removed, using an infrared filter may be a viable alternative. Others who have disassembled their phone cameras (why not?) suggest looking elsewhere. The trouble is, Apple has their vignette and color correction all set up for the original lens and how it casts light into the sensor, and that all gets thrown off when you slap on some new glass, resulting in a tint. However, turning off lens shading in an app resolves the issue. The light leaks from the earlier iteration are basically gone, but there’s still a small sensor, a long crop, soft edges, and a 4:3 frame that appears more like vintage film than an iPhone shot.
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