The controller controls the DSLR camera shutter, and can be used stand alone or connected to a computer. When connected to a computer it can be used in a focussing mode, which is very useful, and can then be used to acquire and download the exposures as required.
When I first received it the mirror lock up function did not work properly, but the people at Cercis Astro quickly solved this with an update when I informed them of the problem.
The software still has some quirks, but I now know what they are now and I work round them. For example, if you program in an exposure of 300s it takes one of 305s. Not a problem when you know it does this....but not expected!
When connected to a computer, the sequence menu allows a sequence of exposures to be taken, and this is the menu that I use the most. Although the screen shot to the right would indicate that you could take exposures using the expose button, time and series boxes, I try not to use this. I find that when I do, it unpredictably and often hanges up with a message about loosing a thread. I have to say I do find this puzzling. When I set it all up to test it in the house, with the exact same set up, cables etc, I cannot get this fault to occur. However, the moment that I have it set up to use outside I get problems. Perhaps it is something to do with the cold, perhaps as the camera/DslrStar electronics get cold, things start to miss behave. Initially I thought that it might be power problems, but I now have powered USB hubs and transformers for both the camera and the controller, but the problem persists. However, so far the sequence menu works very well so this is clearly the way to use it and just ignore the expose function on the main menu. I have not bothered telling the Cercis Astro people about this fault because it is hard to reproduce in a warm room and the controller otherwise works very well and does the job. I would not change it even if there was an update, I believe that once something is working for you, do not mess with it!
Verdict: I like it and find it useful.
The web address for Cercis Astro is: www.cercisastro.com