Many people have been asking when GBTimelapse will be compatible with Canon's newest - the 5D Mark III. And the answer is: the Beta version is ready! Just go to this download link. The newly compatible GBT will install over your current version, and there's no need to re-register your license. If you don't already own GBT, you can install as a new free-trial.
Beta 5D Mark III
I quickly incorporated Mark III compatibility into GBTimelapse as soon Canon released their new software development kit. I've done some bench testing and captured a simple sunset Holy-Grail time-lapse, but I haven't yet done extensive tests. I plan to do more field testing this week.
Because of your requests, I've decided to release this new version GBTimelapse 3.4.1 with Beta support for the Mark III. I don't expect problems, but will be anxious to learn how it works for you.
New ISO 50
The Mark III now has ISO 50! This is a great addition because it makes bulb shooting that much easier - a lower ISO allows longer bulb times. Make sure to configure your Mark III for this new ISO.
Turn off noise reduction
And, while you're at it, make sure to turn off "noise reduction". Noise reduction can add many seconds of camera processing time when shooting RAW images at high ISO. This can painfully increase the time-lapse interval when doing sunset or sunrise time-lapse shoots.
Changes in the 5D Mark III
GBTimelapse' design makes it is relatively simple to add a new camera model. However, the Mark III was a bit more challenging, because there was a major change to the EOS Software Development Kit (EDSDK) design. The new version removed the ability to change AEMode remotely on cameras with a mode dial (like the 7D and 5D). The AEMode dial is the one with settings for P, Tv, Av, M, and Bulb.
Earlier EDSDK versions allow AEMode to be changed remotely.That's a neat ability because it makes it possible for the GBTimelapse AutoRamp feature to automatically switch between Manual and Bulb mode. This is necessary sometimes when shooting very long time-lapse unattended, when it's not practical to stay in Bulb mode and manually add or remove ND filters.
I've added a new camera group (Group 3) just for the Mark III and I've kept the 7D and 5D Mark II in Group 2. Group 2 cameras retain the ability to change the AEMode remotely (except for the XTi, T3, T3i and 60D) .