From: "k.logg" <k.logg@yahoo.com>

Date: July 31, 2006 1:21:34 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: Transit of Io 16 June 2006


Hi


A bit of typo-itus crept in to that last post. Proof reading was never

one of my strong points:


kind words and greatly appreciated - phew, that feels better ;-)


Cal

PS I'm ignoring any other typos there may be.



--- In Astro_IIDC@yahoogroups.com, "k.logg" <k.logg@...> wrote:


Hi Alan


Thank you for your kinds words and feedback, it's greatly appreciate

and immensely helpful.


I am really pleased with the image, all things considered. I wasn't

sure if that was oval BA, I spent the following couple of weeks

looking for images of Jupiter from the same day to confirm it. I never

did, so I'm glad you mentioned it.


With a lot more practice and a little bit of luck I may be able to

take images half as good as yours.


Cal


--- In Astro_IIDC@yahoogroups.com, Alan Friedman <alan@> wrote:


Hi Cal -


That's a fine first image. Great to record the transit and you can

just 

make out oval BA (aka red jr) to the lower right of the GRS. Color is 

very nice.

There is some debate on how to record the seeing quality - all of the 

methods will become more meaningful with experience. I use a simple 

"report card" method now - poor (would have been better to go back to 

sleep), fair (4-5 Pickering), good (6-7 Pickering), excellent (pinch 

myself to make sure it's not a dream). Needless to say fair/good

covers 

99% of the conditions at my location when it is worthwhile to image.


Gamma at 1.6 seems high to me - I usually use 1.0 to a max of 1.3

with 

my B&W DMK camera (not sure if the settings have the same meaning

with 

your camera). But the image quality doesn't indicate a problem to my 

eye and I think there may be an advantage to stacking to increase the 

contrast in the frames. I usually use a lower pixel matching

tolerance 

too but it seems that most of the selected frames were stacked so it 

doesn't seem to have been a problem at this image scale.


Look forward to seeing more of your images.


Alan


ps - no apologies needed, but thanks for the reference! 8^)





On Jul 31, 2006, at 11:50 AM, k.logg wrote:


Hi all


This is my first ever image. It was only meant to be an exercise in

familiarising myself with Astro IIDC. It was pure luck that I

captured

the transit of Io on the 16 June.


http://groups.yahoo.com/group/Astro_IIDC/files/Planetary/Transit

of Io

16 June 2006.jpg


As I'm new to this I don't know how to quantify the seeing,

transparency. It was clear but not very dark this close to the

Solstice and the atmosphere was pretty turbulent, particular as

Jupiter was so low in the sky. Hence so few frames captured using a

Unibrain Fire-i colour webcam at f10 on a friend's 8" LX200 (altaz)


Below are the logs from Astro IIDC, any comments will be gratefully

received, as I really have no idea what I'm doing.


Settings for Astro IIDC image capture were as follows;


Gamma: 1.64

Saturation: 36

Blue Gain: 115

Red Gain: 69

Brightness: 102

Black Point: 248

Exposure: 133.33 ms


Settings for Astro IIDC stacking and processing:


Stacking : 8 Bit Movie

CI Cutoff: 60 %

Aligned Using:Luma Channel

Gross Alignment: Planetary

Pixel Alignment: Horizontal and Vertical Separate

Pixel Alignment Block Size: 32 x 32 pixels

Pixel Matching Tolerance : High

Scale Frames by: 1 x

Frame Sharpening: Medium

HighQuality Bayer: Off

Auto Clip Area: On

Averaging Images

Sharpness Statistics: Min 0.759031 , Max 0.833257 ,

STD0.013007 , Mean 0.795522 , Median 0.795564 , Mode

0.793824, CutOff Value 0.802748

Pixel Noise Percentage: 0.392157

Main Image Centroid X:243.7, Y:205.8

Pixel Area One Centroid X:270.7, Y:189.8

Pixel Area Two Centroid X:234.7, Y:227.8

Stacked 198 out of 680 frames


Final processing using Photoshop.


Best wishes

Cal


PS Apologies to Alan Friedman as I've pretty much copied your

method

of presenting the image.