From: "Tim" <tjp314@pacbell.net>

Date: March 21, 2007 11:01:47 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: Saturn March 20!

Jim:

You might want to check to see if they have graphs of the performance

of those particular filters.  Not too many years ago, there were only

a couple of suppliers of dichroic filters that got the seller's brand

engraved into them.  The purple cast seems to suggest that IR is

getting through and affecting the blue channel, in particular.

You also might want to know how well the IR block filter is supposed

to perform.

-Tim.

--- In Astro_IIDC@yahoogroups.com, "jimchung2338" <jim_chung@...> wrote:

Thanks for everyone's helpful responses from yesterday!  Last night

the greater Toronto area 

experienced good skies and I think it helped my imaging of Saturn:

SaturnLRGBMar20.jpg  in the Planetary folder

Alan:  Hope you were able to image last night, Buffalo probably had

similarly good skies

Tim:  I am luckily using dichroic RGB filters that came with this

budget priced Apogee filter 

wheel - don't know if it's worthwhile spending more on name brand

filters?

Phil:  I generally use an IR blocking filter upstream of the flip

mirror to avoid and color 

imbalance.  I've also been balancing my colors by making the rings

as white as possible, is 

there a PS tool that allows you to designate an area a certain color

and then auto adjust the 

other areas relative to that one?

Jim