Re: A Crab from polluted waters

William R. Mattil a écrit :
All,

I ran some tests with the 253mm f/4 on the AP1200 mount and used the ST-7 from my backyard. This really started out as guiding tests, trying some different techniques that enabled the system to calibrate and track.

http://www.celestial-images.com/Images/M1-4x600s-LHaRGB.html

As I said this started out as an experiment but the tracking was excellent considering the 25mph wind gusts. Since I was using the internal guide chip the Ha filter presented some extinction so the guider integration was 10 seconds.LHaRGB image 4x600 seconds with 2 extra Ha subs added in. originally took 23 subs and one was lost due to the gusty conditions. The Ha data was combined with both the luminance and red data before the final color stack. Pretty severe gradients but GradientXterminator really did a great job in lessening the impact from my mag 3.5 backyard.skies. Basically just levels and very slight curve stretch and a very mild unsharp mask on the Crab itself. I was quite surprised to find that I easily caught the Mag 16 Pulsar progenator of the Crab itself. Surprised me.


Nice picture for a test :)

--
Norbert. (no X for the answer)
======================================
knowing the universe - stellar and galaxies evolution
http://nrumiano.free.fr
images of the sky http://images.ciel.free.fr
======================================
.