I tried a shotkam out today for the first time.
To start with, the front of the cam is to be (according to instructions) no further back from the muzzle than ten inches, presumable this is so that you don't get too much barrel (muzzle) in the top of the pic. I mounted this one exactly ten inches back and I can see the bottom of the barrels in some pics but not all of them. I'd like to try it further back just for kicks as the weight out front is noticeable and no doubt will affect some people's swings. I shoot a heavy gun and I did notice the extra weight and I don't think it affected me still, I'd like to get the weight back as far as possible away from the muzzle.
We viewed the video's on an Ipad after a few shots and the definition is impressive to say the least. The target is well defined and I'm happy to say that the cross hairs showed no canting of the gun as I shot! It's really noticeable when the shot is taken as the cross hairs jiggle slightly from the recoil, there's a large blur as the pellets and wad burst from the muzzle and a few frames later you see the shot string and wad all flying towards the target. It takes several frames for the shot to reach the target, especially when we shot some 40 yard crosser's, but I was somewhat disappointed that when the shot column reached the target, the pellets were getting somewhat difficult to see. We were shooting shells with #8 shot and I found myself wondering if using #7.5 shot and having the sun at my back might show the shot string a bit better, dunno. You can definitely see what part of the target gets hit if you don't center it, the back edge comes off or the front edge, maybe the left or right, even if you can't see the pellet string it's pretty evident where it is if the target breaks just by the way it breaks.
Is it a good tool for a shooter who wants to improve their scores, yes, no, maybe... depends..... It's definitely a lot of fun to play around with! I think there would be lots of invaluable information there for someone just starting out shooting clays as long as they are reviewing the video's with an experienced instructor. For myself, I've shot for many years and for the most part, I know where I'm missing a target but for those ones that I just can't figure out, this may have some benefits.