Is there a good telextender that has enough resolution to use with the FX1 and Z1? Are the ones that are sold by Sony really sharp enough to do the job? How does this question apply to telexes for high-MP still cameras? Are there some telex models that could be used for both HD-video and high-MP stills?

I have FX1, and have used Sony's VCL-HG1758 1.7 teleextender on it. I needed a step down ring to match the threads. It works decently, I think. Of course, it will not zoom wide, however, as severe vignetting will occur on the wide setting. Picture is decent, considering it was originally designed for lower definition specs.

See the links I posted in this recent thread as they cover your questions:

http://www.dvinfo.net/conf/showthread.php?t=75010

If using a step down ring, be sure to test for vignetting using a monitor that shows the full frame. The Z1 has allscan mode for this but the FX1 does not. Every consumer HD screen I've seen also overscans and doesn't show the full frame. Looking at the footage on your computer should show the full frame.

Vignetting may also show up as a darkening of the image towards the corners instead of actually chopping the corners off. Depending on what you're shooting this might or might not be obvious.

We're using the Century Optics tele-extender on our Z1 and FX1.
It does a good job within the range of 50 to 100 on the Z1's zoom scale. Go below 50 (or the halfway bar on the FX1) and serious vignetting will occur.
I like the bayonet fitting with this lens - much better than having to screw/unscrew an attachment.
Using this degree on magnification really shows up the deficiencies of cheap pan and tilt head combos like the 503/525 however. You really do need good solid tripod legs and a decent head if you want smooth, steady moves at full telephoto.


Robin