View Single Post
  #3  
Old 14-07-2008, 03:38 PM
Globular3's Avatar
Globular3 (Jeff)
Registered User

Globular3 is offline
 
Join Date: Aug 2007
Location: Sydney, Australia
Posts: 47
Quote:
Originally Posted by Dennis View Post
Hi Glob

I think that Par focal is more a property of a range of eyepieces, meaning that when one eyepiece is focused, you can simply replace it with the next one and in theory, the focus should be spot on.

From memory, I don’t think that my TeleVue x2.5 and x5 PowerMates (1 ¼ inch) are parfocal – I recollect having to adjust the focuser when changing PowerMates with either a ToUcam or a DMK CCD camera plugged in.

I have a TeleVue x5 PowerMate in the 1 ¼ inch fitting and in my experience, I have only used it visually on my Vixen 102mm F9 ED refractor a few times, mainly to split double stars.

A x5 PowerMate will convert your 80mm F5 to an 80mm F25 system and you will probably be disappointed with the views?

Cheers

Dennis
Hi Dennis,

Thanks for letting me know this info.. So I'd probably have to wind the focuser in a bit (I think this is the correct way???) with the powermate. Also, I wanted to use the high power to resolve double stars, see better planetary detail and improve my lunar observations. The 3x barlow (even though its a cheap one) gives a real improvement to the detail. Bearing in mind that I don't need the rich field property of the refractor for this type of work, do you still think the 5x powermate (or barlow) wouldn't be a good choice?

Regards,

Glob.
Reply With Quote