From: Milton Aupperle <milton@outcastsoft.com>

Date: April 27, 2005 9:05:44 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] copernicus

Hi Alan;

On 27-Apr-05, at 8:10 AM, Alan Friedman wrote:

Hi all -

I went back into the lunar folder and looked again at Milton's two mosaic images of the

lunar disk. I'm amazed that you could create these from 12 or 13 frames at 1500mm focal

length. It took me nine frames to cover the full disk of the sun at 600mm FL. I guess it

helps to have the sun lighting only a portion of the moon's surface!

Even though we are both shooting with a 640x480 pixel cameras, the color Flea camera I'm using has larger 7.4 micron square sized pixels and is a 1/3" CCD, whereas the 21BF04 TIS cameras Alan uses has pixels 5.6 micron square sized pixels (32% smaller) and is a 1/4" CCD.

The difference is I wind up with a 32% larger field of view for the same focal length - so it takes me fewer composite frames to cover the same area. Conversely to get the same size image out of Jupiter on screen, I have to use a 32% longer focal length which will also amplify the atmospheric effects too.

I also uploaded an image of the copernicus region taken at prime focus of my 10" mak

(3600mm fl).

http://groups.yahoo.com/group/Astro_IIDC/files/Lunar/copernicus_wide.jpg

Very nice image.

Milton J. Aupperle

President

ASC - Aupperle Services and Contracting

Mac Software (Drivers, Components and Application) Specialist

#1005 - 815 14th Avenue. S.W.

Calgary Alberta Canada T2R0N5

1-(403)-229-9456

milton@outcastsoft.com