Televue zoom eyepiece 1.25" 8mm-24mm SOLD

gts055 (Mark) · #1 08-12-2007, 10:32 AM

Excellent condition with original box and caps. OK, I had this listed at $200, and no interest, now its $180 including postage within Australia. Thanks Mark

gts055 (Mark) · #2 10-12-2007, 12:07 PM

price dropped to $180.00

turbo_pascale (Rob) · #3 10-12-2007, 02:23 PM

Mark,

I've never used one of these before. Do you need to change focus when you change zoom, or does it stay (reasonably) in focus throughout the zoom range?

Reason for asking is that I want to use it as a parfocal eyepeice to assist getting the image on a CCD chip. Doing so with a 12.5mm EP only means that often the star I'm aligning on is outside the FOV and I need to keep changing EP's to find the star then re-centre before putting my imager in. A small change in focus is fine, but if gross changes are required, won't be of much use.

Also, I assume this is an older type, and doesn't have any "stops" for particular ranges?

Turbo

gts055 (Mark) · #4 10-12-2007, 08:55 PM

Hi Turbo,

I had no idea about change in focus as the eyepiece is zoomed (it came with a telescope and I have not used this zoom eyepiece), soo, I have just checked for myself now:
On a Televue Pronto (70mm aperture, focal length 480mm, f6.8), the difference in focus is about 1.5mm on the draw tube in moving from the eyepiece indication of 8mm to 24mm. This appeared to be a small alteration in focus, as a visual user that is.
The eyepiece has no detent stops, but does have an indication at 8mm, 12mm, 16mm and 24mm settings.

Thanks Mark

turbo_pascale (Rob) · #5 11-12-2007, 08:27 AM

Thanks Mark for going to the effort to find out for me.

Sounds like it will probably do the job I need.
Got to have a think about it some more though.

Turbo