From: "Milton Aupperle" <milton@outcastsoft.com>

Date: July 3, 2008 6:47:51 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: IR/UV filter...

Hi Mark;

No it wouldn't cause that. It primarily blocks off infra red light

which causes color balance issues (mainly lunar / solar, but Planetary

too like Jupiter) and also improves sharpness as IR light comes into

focus at a different point than visible light.

Usually when you can't find objects it's because the finder and the

camera / scope are not pointing at the same place. The small field of

view at prime focus with most scopes allows for very tight tolerance

in alignment. After I remove the coverings on my scope, I usually have

to re-adjust the Finder scope so that the finder and camera point to

the same object. I usually do this right before dusk and site them in

on a dsitant terrestrial object.

HTH..

Milton Aupperle

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

Hi Milton & others,I`m wondering if the lack of the above filter on

my IS DBK 21A F04.AS 

would be affecting my ability to acquire stars in the camera window

of Astro IIDC. I`ve tried a 

couple of times with my NexStar 4SE (as it`s easier to set-up) but

haven`t had any success 

with more difficult objects. I`ll have to have another go with

Jupiter as I acquired it 2-3 

months ago although quite overexposed with little chance it seems of

adjustment. Now that 

my Firewire port has luckily started working again I can devote some

funds to a Baader filter 

by the end of the month! Mark.