From: "cosmicrock2001" <ursamajor_1@mac.com>

Date: February 6, 2010 11:57:15 AM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: Damian Peach


I use a 5x Powermate with my  12.5" f/6 and it works very well.  But i can rarely use it due to usually poor seeing at my location and have to drop back and use a 2x 3 element barlow.  Folks like Don Parker recommend getting the f/ratio up to f/30 or so for image scale.  


Its not clear in your message if you are stacking your barlows or just use them individually?   If you're stacking them the 5x Powermate will definitely be a big improvement.  Its designed to minimize color and distortions.   If your images are just dark with a 2x barlow sounds like you need to adjust settings, gain, brightness, frame rate or exposures in Astro IIDC.   Jupiter is especially bright and should be 'easy' to get good exposure.   


HTH 


Ron

in turbulent foothills of Rocky Mtn's. Colorado


--- In Astro_IIDC@yahoogroups.com, Mark Gaffney <markgaffney@...> wrote:


My attempts to barlow (2.4x & 2x) Jupiter a while ago were very noisy  

& dark..I`m wondering if the seeing was working against me or whether  

a Televue type would work better than my cheapo Vixen etc. ones..Have  

you or anybody else ever used a Televue 5x barlow for instance..?


Mark.