Backbone Ribcage – Interchangeable lens system for GoPro 3

News

by Tim FokDecember 6^th, 2013

Backbone’s debut product is sure to excite GoPro 3 users. The Ribcage is a modification kit/complete camera solution that provides an interchangeable lens system for the GoPro 3.

The ribcage is compatible with both the Hero 3 and Hero 3+; it’s available as a complete camera or a modification plate to your existing GoPro Hero 3/3+. Neither options come with a lens, you have to purchase/adapt these separately.

Both products provide you with a C-mount GoPro that will accept any form of lens that’s compatible with the C-mount format.
As well as lenses native to this mount, you can mount an array of lenses such as Nikon, Canon or Sony mount with an additional third party adaptor. Due to the tiny flange distance, there are very little lens systems that won’t be compatible. The restriction is more likely going to be down to the manufacture of an adaptor to C-mount.

This offers quite a unique package. GoPro has had immense success that far outreaches the filmmaking industry; their popularity in the consumer region is quite overwhelming. GoPro has been offering a steady supply of significant upgrades over the years. 120 fps, (ignoring the sub HD 240 mode) 2.7K full HD resolution capture, (ignoring the 4k 15fps mode) flat picture profiles – all great updates which has made the compact, shock proof, waterproof package very attractive. Yet on its 3rd major revision we’re still limited to auto exposure and a fixed f/2.8 lens.

Due to these restrictions (namely the latter) it’s still fairly easy to spot a GoPro shot amongst other camera formats; the wide, distorted angle of view is quite tell-tale. The Ribcage tackles that problem. With compatible lenses you can now retain control over your aperture, focal length and focus, and with the right selection you’ll be able to achieve the likes of swallow depth of field, macro and tele-photo acquisition.

It’s important not to get too far ahead. This is a lens modification; it does not change the size of the sensor therefore true control of your depth of field will largely be reserved for extreme tele-focal lengths due to the GoPro’s small sensor. However, with the small sensor and 35mm lens adaption this may not be as tricky to achieve as you think. The GoPro hero 3/3+ has a 1/2.3″ sensor that provides a crop factor of 5.7, resolving your 50mm full frame lens to a tasty 285mm.

The fact that we are still limited to auto exposure on the GoPro is disappointing. Whilst with the ribcage we’re able to have more control over the shutter speed and ISO by selecting our aperture and adding ND, we don’t have a final say over the exposure settings due to this firmware restriction.

It’s reminiscent of early 5D Mark II days, although these were better as at least there were work arounds. Exposure lock or auto exposure override is surely a feature in the pipeline for GoPro. If it’s not, it really should be. As it stands, GoPro are behind in this department; competing compact camera manufacture Drift Innovations has exposure compensation in their Ghost camera, GoPro has nothing.

Back to the Ribcage, as well as the c-mount feature it also has a removable tripod plate and removable IR cut filter. An IR cut filter (as the name suggests) cuts out infrared light, removing this means IR light reaches the sensor, offering a fairly unique look for video, and particularly useful at night.

Here are some test shots by Ribcage, using an 11.5 – 60mm f1.4 C-Mount zoom lens, shoot at 720 120fps on a Hero 3+. The Vimeo description is worth noting here:

“The fourth shot of the bee (1:05) begins at an F-Stop of 1.4 and ends at F16. The GoPro keeps up nicely with the dynamic change in F-Stop.”

Both the Ribcage camera kit (GoPro Hero 3+ with ribcage pre-installed) and the ribcage mod-kit are available for pre-order. Priced at $799.99 and $199.99 respectively. I eagerly await an upgrade/hack for the GoPro which provides exposure control/lock as this would truly make the Ribcage a very powerful tool.