Zoom Eyepieces

[Hans Tucker (Hans)]

Are Zoom Eyepieces all they are claimed to be?


Looking at the Pentax 6.5mm - 19.5mm XF Series Zoom Eyepiece or possibly the Leica ASPH Zoom 8.9mm - 17.8mm. I can't find much on the Leica eyepieces but one was up for sale recently on Astromart for $825...more $$$'s than the Pentax.

[mercedes_sl1970]

There have been some discussions on the Leica zoom on Cloudynights:
http://www.cloudynights.com/item.php?item_id=2390
http://www.cloudynights.com/item.php?item_id=2795

And then this one comparing it to Baader orthos:
http://www.cloudynights.com/ubbthrea.../o/all/fpart/1

Re the Pentax zoom - I understand that the XF, while quite good, is inferior to its sibling, the Pentax 8-24mm SMC. I did have the latter for a while and it really was very sharp, had good contrast and produced very good views. I ended up selling it as I just wasn't using it enough.

Andrew

[LewisM]

I have the Vixen Zoom, and I find it quite OK. Perhaps not ENTIRELY parfocal,but I do find if I focus at the high power first, then the lower powers are better by far,but I suppose that is par for the course anyway.

[Davi5678 (Dave)]

I have the pentax 19.5 - 6.5, it may be a one off defect, but it has ghost images and 'kidney beans' making it frustrating to use.
I'm tempted to replace it with a Baader 8 - 24mm at some point.
I'd sell it but I honestly can't in good conscience.
When it does give a clear view it's quite good and it seems to get most use for Jupiter and Saturn where you can adjust to the seeing conditions.