Nothing flashy; another test exposure through less than ideal conditions: NGC 6188

[Octane (Humayun)]

Hi all,

My second ever CCD image.

On Saturday night I headed out to John's place out at Cootamundra for some dark skies (thanks, again, John).

I set up a lot quicker this time, and spent my time drift aligning, all good.

The goal was to devote the night in 10-minute sub-exposures to this region, through Hα and OIII to do a HαOIIIHαOIII blend mapped to LRGB.

However, the weather had other ideas. I ended up managing to get just one hour of data, all shot through increasing fog. The halos around some of the brighter stars are a testament to this.

Target: NGC 6188 and NGC 6200 down the bottom
Scope: Takahashi FSQ-106N
Camera: SBIG STL-11000M (operating at -40 degrees; no sweat)
Mount: Losmandy G-11
Exposure: 6x600 seconds, self guided through a 12nm Astronomik hydrogen alpha filter. The only calibration I've done is subtract dark frames. I didn't bother with making flats as I didn't think anything would eventuate from the session.

Captured through CCDSoft and processed entirely in IRIS, with salt and pepper added in Photoshop CS4.

The image is here.

Bash away.

H

[jjjnettie (Jeanette)]

nothing to bash, it's beautiful!

[gregbradley]

You're off to a good start with your gear. Shame about the weather. We are like surfers or skiers/snowboarders who are constantly checking out the weather.

That's a long way to drive and setup in the cold for an hour's worth but its all good fun though.

Still, makes an observatory a valuable thing eh?

Greg.

[multiweb (Marc)]

Great field. Very sharp.

[Hagar (Doug)]

Very nice H, Youve got it singing well now. Can't wait till you get some colour going.

[Tilt (Michael)]

Very nice H

It shows how much 'space' you can grab with the FSQ-106 + STL-11000 set up.

Michael

[Moon (James)]

H
For the Ha filter, I found it seemed to work better with 20min subs. Now I'm thinking of trying 30mins next time.
Have you tried to guide through the OIII filter yet? How did it go?
James

[marc4darkskies (Marcus)]

You're definitely cooking there H!!

With Ha though I'd strongly recommend longer subs - at least 20 mins. I always do 30 mins with my 10nm Ha.

Cheers, Marcus

[Octane (Humayun)]

Jeanette, Greg, Marc, Doug, Michael, James, Marcus,

Cheers, guys!

James -- guiding through the OIII filter was easier than the hydrogen alpha filter. I'm not sure why -- I think John mentioned that the the OIII filter was predominantly for visual; it was a Televue of unknown bandpass. Was worth a shot, anyway, but, nothing eventuated due to weather.

Marcus and James -- you guys are spot on, the 10-minute sub-exposures were rather faint. It was just a test, though. In future, I will definitely aim for 20-30 minute exposures. I had to push this one quite a bit in post. I'm really surprised at how much latitude there is in working with FITS files. It's awesome.

Cheers.

H

[jase (Jason)]

Originally Posted by Octane

I didn't bother with making flats as I didn't think anything would eventuate from the session.

Never say never H! Anything is possible!

No flat calibration has given the image the appearance of looking through a key hole due to the light drop off towards the edges. All the details are there and the framing is impressive. May help to get a flat box for field use.

Cheers

[Martin Pugh]

Hi Humi
yep, another fine image.

library flats are great, as long as you do not change your optical set up of course....and you really should check out the FlipFlat - I have one for my FSQ106 and its just brilliant.

regards
Martin

[Octane (Humayun)]

Jase, I know exactly what you mean, mate. I saw the light fall off when processing it and it was annoying the crap out of me. I regret not having taken flats now, because, otherwise, it's not so bad an image.

Martin, cheers, mate. I will have a look at the Flip-Flat now.

Thank you, guys!

H

[CoolhandJo (Paul)]

Lovely crisp image. Stars are tight. The future is looking bright!