From: Alan Friedman <alan@greatarrow.com>

Date: March 27, 2012 11:36:39 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Venus True/False

Thanks Milton,

The bright regions represent the highest albedo in the cloud tops... though beyond this I don't know. I did find that the cloud rotation is quite fast... obvious movement is seen in 30 minutes. As you've guessed, the data is shot at high gain and is quite noisy. One has to take as many frames as possible in a short time span. I used both 33ms and 66ms shutter settings. 33 required maximum brightness and the frames were still quite dim. 66 could be used with the brightness slider setting down to 640, though the resulting frames were softer. Here is a single frame from one of the 33ms streams:

http://www.avertedimagination.com/images/33_1.jpg

best,

Alan

On Mar 27, 2012, at 1:19 PM, Milton Aupperle wrote:

Hi Alan;

Exceptional images. I wonder what causes the bright spots on the north
and south limbs?

Shooting at 10.14 meter focal length? What sort of exposure were you
using?

It might actually stop snowing / raining / fogging / blowing here on
thursday, so I can use my scope after a 7 week imaging drought.

Thanks for sharing..

Milton Aupperle

On 26-Mar-12, at 4:19 PM, Alan Friedman wrote:

>
>
> Hi all,
>
> After struggling with light throughput from my 8nm Baader K-Line
> filter, I decided to follow advice and purchase a wider band UV
> filter from Astrodon. These results were obtained March 22 using my
> 10" Mak/Cass at f40 and Flea3 monochrome camera. Image capture and
> stacking in Astro IIDC, processing in Astro IIDC and Adobe Photoshop
> CS3. I shot the UV data about an hour and a half before sunset.
>
> False Color/ RGUv:
> http://www.avertedimagination.com/img_pages/Venus_True_False.html
>
> UV only:
> http://www.avertedimagination.com/img_pages/VenusinUV.html
>
> best wishes,
> Alan
>
>
> Alan Friedman
> avertedimagination.com