The design prototype feels nice in the hand but does not offer any functionality.

Photokina's big brand launches often overshadow the announcements from lesser known or smaller manufacturers, but we were lucky enough to spot the Relonch camera in Hall 2. And it's definitely one of the more interesting exhibits at this year's show.

The Relonch is a "slide-on" camera module for the iPhone 5 and 6 that comes with an APS-C sized image sensor and a fast prime lens. However, at this stage most of the exhibits at the Relaunch booth are non-working design models. The only working unit is a prototype with an F2.0 lens that's much bulkier than the anticipated final product, and held together with duck tape. It's also tethered to a PC, which is currently still doing the processing.

The iPhone 5 or 6 slides in at the back.
The shutter button on top is the only control.
The working prototype is much bulkier than the design model.
The app is as simple as the device design.

The production model will connect to the iPhone via the Lightning connector and transfer JPEG files from the camera module to the iPhone. There they will be further processed in terms of sharpness and contrast, and then saved to the camera roll for further sharing opportunities (e.g. iCloud or Dropbox).

No detailed specifications of sensor and lens are known yet, but the final output will be square and limited to only 1MP. The camera app will be extremely simple, with a black and white mode as the only option. On the module itself the shutter button is the only physical control.

Offering a large sensor and fast lens, along with simplicity taken to extremes, the Relonch camera does look like a niche device. However, if it ever makes it to production stage, it'll be interesting to see how consumers respond to it and what use cases they will come up with. Relonch argues that Instagram images are only 0.4MP in size and therefore no larger image is required from your camera. Of course this is only true if you never crop your images or view them on high-resolution screens, use the digital zoom or, god forbid, use a photo printer. And while the large sensor should, in theory, provide low noise images in low light, it does seem a bit odd to not take advantage of the larger sensor's copious room for more pixels.

If you are happy to limit yourself to social network image size and have enough faith in the project you can preorder a Relonch now for US$499. Delivery is anticipated in late 2015. You'll find more information and the order button on the Relonch website.