From: Mark Gaffney <markgaffney@me.com>

Date: February 6, 2010 1:49:29 PM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Re: Damian Peach

Hi Ron, 

Last time with Jupiter I was getting this at prime focus with the Scorpion 20SO & my C9.25..

& this for example with the 2x barlow I have.. & I seem to remember I couldn`t improve it no matter what I did with the focus, brightness, frame rates or exposure..I mean this was the best I achieved on that night barlowed...

My 2x barlow certainly isn`t of the quality of a Televue though..! The Vixen 2.4 extender was worse still..

Mark.

On 07/02/2010, at 5:57 AM, cosmicrock2001 wrote:

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.