From: Milton Aupperle <milton@outcastsoft.com>

Date: January 18, 2010 4:10:20 PM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] New AstroIIDC user

Dear Kurt;

On 18-Jan-10, at 3:24 PM, mihalco wrote:

Hi Milton,

I recently picked up a Pt. Grey Scorpion SCOR-20SO (1600 x 1200 mono) from the guy on EBay, and am about to give AstroIIDC a try (I'm waiting on a Firewire B to A cable).  From the feature list, it appears that it is possible to capture 16 bit video sequences and align and stack them.  Just want to confirm this is accurate before purchasing.  My main use will probably be with the 800x600, Y16 at 25fps (Format 1, Mode 6) for Planetary.  Also, probably will try the 1600 x 1200 Y16 at 7.5fps (Format 2, Mode 7) for solar.  I'll be running on a new Intel Macbook Pro - will AstroIIDC be able to keep up with these frame rates in Y16 out to disk?  Any other caveats I should be aware of?

Thanks,

Kurt Mihalco

Everything in the above is correct, except the frame rates.

Your not going to get 25 fps out of the Scorpion SCOR-20SO. The maximum frame rate is about 17 fps when ROI cropped to 800x600 size AND you set the CCD cropping to the upper left corner at 0,0. That CCD simply don't transfer a lot of data per scan line above 14.98 fps, even though we can allocate more bandwidth for the camera,

It's a FireWire 400 cameras so the maximum legal isochronous data rates is 80% of 400 mbps, roughly 38 megabytes per second. So you can run 1600 x 1200 in 8 bit at 15 fps or 1600 x 1200 in 16 bit at about 10 fps. About the largest size you can go in 16 bit and achieve 15 fps is about 1150 x 1150 pixels (which is about 38 megabytes of video data per second or 2.2 gigabytes per minute of recording).

It does have small (4.4 micron) pixels, so running at higher frame rates for planetary likely won't be doable except with a light bucket scope (i.e 12" or larger aperture).

HTH..

Milton Aupperle