From: Milton Aupperle <milton@outcastsoft.com>

Date: March 24, 2010 9:15:23 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] New Images

Hi Mark;

It's around Mag 10. I shot luma but the turbulence was bad

http://en.wikipedia.org/wiki/Messier_61

I doubt if you'll pick up anything at 60 second exposures per frame.

With the Grasshopper (the CCD is about 4 times as sensitive as the the one you have in the Scorpion), I need a 15 minute exposure with a C8  to get the central core area of M61 to be at 35% saturation (24,000 out of 65,535). If you binned it 4x4 and cranked the gain / brightness to maximum, you might pick something up for 60 seconds, but it won't be very pretty.

TTYL..

Milton Aupperle

On 24-Mar-10, at 8:49 PM, Mark Gaffney wrote:

Hi Milton,

I looked at  M 61 too though I think it`s smaller & fainter than M 66 from memory...? Here`s a combined LRGB filter simulation (photomerged in Photoshop) I did, with the Scorpion 20SO`s spectral details entered, at about 60 x 60 seconds per filter... so 4 hours of imaging..

Mark.