I am somewhat of a beginner, and I am having trouble shooting star trails. My problem is that when I set up my camera to take startrail pics I was First using a intervelometer and setting it up as such; Delay 5 seconds/ Shot 2 mins./ break 5 sec. / Shot 2 min./ Break 5 sec. so on and so forth for a total of maybe 25 shots to start. When I try it, I get the delay, and then the first 2 min. shot, then a 5 sec. break, then I hear the shutter noise but the shutter does not shut and stay shut for 2 more minutes. I find that after the first 2 min shot it takes 2 more minutes before I can take another.This continues to happen. So I then thought that maybe it was a slow micro sd card (SanDisk Extreme 32GB V30 HC1 U3 A1). So I purchased a new Lexar Professional 64GB 150MB/s SD V60 U3 XCll C10 1000X. I find that I am still experiancing the same problem. What am I doing wrong? Please help.