Lagoon nebula-Attempt 3

[Barry]

Did these two last night.

Darker image-
10 x 30 second light frames at ISO 1600, 10 x darks removed, stacked and processed in deep sky stacker.

Celestron Nexstar 11, equatorial wedge alignment, Canon 400D, prime focus on a waxing gibbous moonlit night. Also used one of those ambient light filters on the camera adaptor. The resulting shot was a little darker, but way more detailed.

http://www.aussiepeople.com.au/asign...otography.aspx

Removing the darks seems to have made all the difference.

Conversley, I opend the shutter on the same target and just let the telescope go with it's own tracking for fifteen minutes. (Fell asleep) Have a go at what it did! (Brighter image with trails) I have no idea how to refine this tracking. I'm thinking when I get the ED80 on top, I will have to guide manually.

Baz.

[weixing]

Hi,

own tracking for fifteen minutes

15min is too long for unguided Astrophotography especially for such a long focal length (C11). Did you use a Focal Reducer?? Use one if you didn't and try to do drift alignment until you can get a decent image without much star trail at 1 min exposure... it'll not be easy for such a long focal length scope, but you only need to align once since your scope have an observatory.

Just my S$0.02.

Have a nice day.

[Barry]

No mate,

There was no focal reducer. The telescope (fork-arm) is aligned equatorial south on a wedge.

Baz.

[Meng Lee]

In my opinion, you can put the ED80 on top and use an autoguider to guide. I think Celestron Aux port can do that. Check its controller for setting autoguider speeds.

Then put in a f6.3 reducer and then put the 400D camera. Then enjoy long exposures!