is DVCAM compressed ?
 

Is DVCAM compressed like MiniDV ?

(sorry if this has been asked before, could not find it anywhere)

YEP! Same format for compression, slightly different tape pitch (15 vs. 10) to improve reliability.

so dvcam is more reliable, not better quality .. I assume (I have a PD150 wich takes both formats)

Yep, and in DVCAM comes in larger tape sizes. A 60 minute MiniDV tape will only run 40 recorded in the the DVCAM format. The larger tape cassettes that are available in DVCAM allow for much more tape therefore much longer record times.

DVCam is not necessarily more reliable. It was designed for use in linear editing systems and heavy reuse of the tape.

The longer DVCam tape loads are found only in larger cassettes and those will not fit in the PD150.

There is no real benefit to operating the PD150 in DVCam mode unless you are giving the tape to someone who wants that format or you are operating in a linear editing environment.

Other advantages:
1- gets over the mini-DV stigma It's a PROFESSIONAL format ;)
2- It has locked audio which implies better clocks. If you're working with Final Cut Pro you won't get the sync problems of the Canon XL1.

Otherwise the format is not much of an improvement over mini-DV.