The HVR-Z7 remote commander has a photo button which will give you a photo on the Memory Stick Duo while playing the video. Unfortunately, due to the delayed response of the remote, action highlights are easily missed, even when using the slow advance with pause. It sometimes comes down to 1,2 or 3 best frames.
To do them in FCP would be the go, but there I get 16:9 squashed into 4:3, thus a distorted still photo. I am using FCP 5 and have found no info or remedy to that problem in the manuals. On some stills the effect is not too bad, but it would be nice to process the stills in the computer without distortion (in 1440x1080 square pixels), as the best frame (I shoot HDV 1080p25) can be picked effortlessly without the need to shuffle the tape back and forth.

I'd appreciate a short word of advice from anyone who previously tackled that task with a successful result.
Thanks, Gerd

Your frame grabbed from HDV will be 1440 pixels wide x 1080 pixels high. Pixels intended for display on a rectangular grid.

Use any still image editor you like to change your chosen frame grab (in square pixels) to either:

(a) wider: to 1920 pixels wide x 1080 pixels high, or
(b) shorter: to 1440 pixels wide x 810 pixels high.

I prefer to use the former.

Thank you, Martin, I'll experiment a bit.
Ciao, Gerd.