I noticed that some people had difficulty transferring video from their Panasonic PV-GS500 camcorder.  The solution for me came when I found a DV to Firewire cable.  I used the bottom connector as shown below for the camera connection and the Firewire 400 went into the Mac laptop.

The computer I used is a Macintosh Macbook Pro, 15 inch Early 2008 and OSX Yosemite.

What was really wonderful was that both programs immediately recognized the transfer and both programs allowed me to control the camera from the software.  For Premier I had to choose “Capture” to make Premier “see” the camera.  I could completely control the camera from the iMovie application and Adobe Premier Pro CC (2015).  I really prefer to use Premier Pro.  It has a definite learning curve but you get a ton of options and a lot of different methods to work the project.  I found that iMovie would really overheat my laptop while Premier allowed my computer to run cool.  The Premier editing options are really terrific.

I love to walk away from the capture process some times and I know that in iMovie it is so easy to cut out the extra blue screen out.  I think I am correct in this.  Premier puts my computer capture process into pause at the end of the clip, thus saving me some editing.

I hope this helps you.