From: Mark Gaffney <markgaffney@mac.com>

Date: March 26, 2008 8:12:52 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] dancing with the moons...

That`s interesting Alan, I have a 2x and a 3x Barlow, both fairly inexpensive jobs (the 2x is a Vixen) but so far have found particularly the 3x is unco-operative except for lunar sightings. As for taking pictures through them, I haven`t managed that juggling act except for the moon and that was with my old Nikon SLR. I`ll take your prescriptions for shutter settings and Gaussian blur into account when I try taking pictures of Saturn, although you`re using a monochrome camera aren`t you- hence the use of filters! I recently bought CS3 Extended but am still familiarising myself with the quite complex controls. If you go to the recent link on the home page for Astro IIDC you can view my site (made with iWeb). The "10 inch" shot was altered somewhat with CS3 before labelling with Appleworks. Yours Mark.

On 27/03/2008, at 4:14 AM, Alan Friedman wrote:

Hi Mark,

I use both 2x and 3x the native focal length (3.7 meters) for imaging the solar system with my 10" scope. The amount depends on the subject and the seeing. I almost never image in full spectrum white light - the light loss shooting through color filters limits the focal length for most subjects to 7.5 meters. I use either a 2x powermate or an old A-P 2X barlow for this. Shutter settings in AstroIIDC for this session were .066 and .133 seconds with gain set almost at maximum. For stacking I used the 'low' setting for pixel matching and chose the gaussian blur option for frame selection and alignment. This seemed to work out very well.

I will go back and do a smoother processing with more frames included when I have a chance. I did want to get this image out there before someone else beat me to it! 

best,

Alan

On Mar 26, 2008, at 6:37 AM, Mark Gaffney wrote:

Yes Alan, It was an unexpected pleasure to stop and look at your animation. I had just
"grabbed" your large scale "Plato" moon shot to send to and show my Dad, what indeed was
possible( given many years of experience, I expect!) Without giving too much away- you must
be using a barlow on the 10 inch scope you have to get so close to Saturn? Is this the case?
I`ve tried a couple of times to look at Saturn through my 10 inch reflector but it was much
further in the distance than you obtained! The rings show quite clearly on the "10" as 
opposed to my o ther "4" though.Yours, Mark Gaffney.