East Coast Stargazing (28th Jan 2011)

kensou · Post by **kensou** » Sat Feb 05, 2011 12:15 am

malaysia is as clear as u can see

andeelym · Post by **andeelym** » Sat Feb 05, 2011 12:36 am

Tell me about it Tim, this happened last week... I setup my gears for a Saturn ob, then clouds started to roll in, thick clouds that looked endless.

After waiting for 15 mins, I decided to give up, packed up my stuff and when I checked back after an hour, just before going to sleep, everything was clear! With Saturn smiling brightly at me. Argh!

timatworksg · Post by **timatworksg** » Sat Feb 05, 2011 3:26 am

Yawn! 3.30am and I took the risk! It's clear...with a thin layer of haze!
Ob at Saturn...nice now that it's tilted! Far away though..lol!

Doing some AP so if all goes well I may have some images to share. Yawn!! Well worth the Yawn!..zzzzzzzzzzzzzz

andeelym · Post by **andeelym** » Sat Feb 05, 2011 3:39 am

Just did some AP of Saturn but bcos of manual focusing and manual mount, its tough to get a clear pic, also limited time as I started late and I have only a window of 20mins before Saturn rises out of my view. Sigh... results are a bit disappointing but nevertheless its still good for me.

orly_andico · Post by **orly_andico** » Sat Feb 05, 2011 4:41 am

darn gradients are killing me... :-P

pixinsight is so darn hard to use, i can't figure it out.

cloud_cover · Post by **cloud_cover** » Sat Feb 05, 2011 8:18 am

Orly.... gradients in a planetary?
Haven't tried pixinsight; its suppose to be amazing?

Post by **rcj** » Sat Feb 05, 2011 9:30 am

Pixinsight is a very powerful piece of software. It is one of the few astro processing software that executes image processing algorithms elegantly and effectively, although at user level it can be daunting, but once mastered, it will deliver what you want. Have used to use it extensively (in fact compulsory!) during film imaging days especially to get rid of sky gradients in wide-field work which is almost always present even shooting in Malaysia. The following film image was processed using PixInsight LE (which is now obsolete) and the sky gradients were minimized using their DBE algorithm. I think you can still download this software and utilize DBE. But take care of the Global Tolerance Parameter since you need to ensure a fine balance between selecting "hot noise" and actual background stars. The sampling boxes need to be correctly placed in regions where sky background dominates, and the more you choose and place on the image canvas, the better, but it will take up more computing processing power.

orly_andico · Post by **orly_andico** » Sat Feb 05, 2011 2:42 pm

Kevin

I was able to get about 7 minutes worth of M42, but due to the amazingly bad light pollution, when I stretch the image to pull out the nebulosity, I also get amazing sky gradients.

I got an evaluation license for Pixinsight (45 days, then you need to buy it, about $150 SGD) but the darn thing is so hard to use. I think it's written by Spanish people. I was following the tutorial for DBE (which includes screenshots!) but it's still so hard to use / follow!

The problem with Deep Sky Stacker is that it has no gradient removal algorithm..

Remus... your statement "at a user level it can be daunting" must be the understatement of the year! hahaha. I am an IT guy and I have a background in image processing from university days, but Pixinsight has me totally stumped!