Omega Cent, First attempt

desler · #1 21-03-2009, 11:03 PM

My first go at Omega, 10 x 1min subs, iso 200, 1000D prime focus on Ed 80, mounted on a EQ6 Pro.

Stacked in Registax 4 and the first time I've applied darks, 6 x subs using dark frame! Finally levels and curves in Gimp.

For the first time last night I seemed to be pretty happy with my polar alignment. One question though, I seemed to get some star trails after a couple of hours imaging, not sure why, ie; Polar align again or just another 3 star alignment with the eq6 pro? I didn't get to play around, I figured 3.30am was pushing my luck with she whom must be obeyed!

Daz

barx1963 (Malcolm) · #2 21-03-2009, 11:08 PM

Very nice. I'm jealous, haven't had any luck with Omega Cent yet!

gregbradley · #3 22-03-2009, 12:26 AM

Nice image. Try imaging with ISO800 as ISO200 is pretty low sensitivity and your losing data. If you are not autoguiding then you may well be limited to 1 minute subexposures in which case I would max out ISO to the highest level (1600 or 3200 depending on what your camera goes to). At 1 minute there should be no danger of overexposing the core.

If your stars trail after a while perhaps your scope balance is off. I have found sometimes a scope may seem balanced when horizontal but may be out of balance when it is at an angle. Check that out.

Greg

desler · #4 22-03-2009, 12:34 AM

Thanks Malcolm and Greg.

Yeah, balance may the issue, hadn't even given it a thought.
Next good night (weather / work) wise I'll try upping the ISO.

Daz

gregbradley · #5 22-03-2009, 12:41 AM

Quote:

Originally Posted by desler

Thanks Malcolm and Greg.

Yeah, balance may the issue, hadn't even given it a thought.
Next good night (weather / work) wise I'll try upping the ISO.

Daz

Its been a while for me but I always used maximum ISO. The arguments are that ISO800 will get better colour and less noise and more depth on a longer exposure. That ISO1600 is more noise efficient in warmer weather.

Also with DSLRs its better to use a transformer power supply rather than the battery as the batttery heats up the camera as it is used creating mor thermal noise.

Greg.

desler · #6 22-03-2009, 11:47 AM

Thanks Greg.

I had noticed with the higher ISO, that I get a fair bit of sky glow from the light pollution. I've read there a filters to help with that, but I'm thinking a bit of dark sky might assist in playing around at that level.

Thanks for the help.

Darren

leon · #7 22-03-2009, 11:52 AM

It's a great image, but I reckon you could get much more detail, with maybe a longer exposure or a higher ISO setting, however having said that you have done well.

Leon

AlexN · #8 22-03-2009, 12:43 PM

I agree with all of the above... A great image indeed! Definitely up the ISO to 1600, and shoot upwards of 10~15 exposures to counteract the noise.... 15x1min subs at 1600 will blow you away compared to 10x1min at 200!

Great first go at Omega Cent! I look forward to getting my first shot of Omega Cent hopefully in the next few weeks!

Alex.