M20 Trifid Nebula

[alistairsam]

M20 Trifid nebula taken from the Snake Valley Astro camp in Vic Australia.
The dark site really helped as this has just 2 x 15min Lum Subs and 2x5min RGB all bin1.
Higher res here

http://www.astrobin.com/full/169235/C/

All processing done in Startools

10inch F4
NEQ6Pro
STF8300m

feedback welcome

Cheers
Alistair

[Shiraz (Ray)]

wow, that's looking really good Alistair - colour and detail are excellent.

For feedback, stars are slightly variable in shape, maybe a tiny bit of tilt somewhere? It may be worth using the Startools shape repair. Noise could be fixed with more data. These are minor quibbles though - its an excellent image.

[RickS (Rick)]

Great shot, Al. Looks like it could have been taken with a large RC scope

[alistairsam]

Thanks Ray, Rick

I'm very happy with it mainly cause it shows the potential of my gear and I learned so much when processing this, trying out different methods in the layers Module and different ways of making masks and noise reduction and so on. So an experiment really.

I've hypertuned my eq6 where I'm getting pretty good guiding, about 0.16 rms at 1m FL and the pec is actually helping the AO at 2hz. All this results in Images that are far sharper than when I started out with the same mount and scope.

As for the stars, yes I know I have minor tilt somewhere. Will weed it out.

Appreciate the comments.

Alistair

[alpal]

Hi Alistair,
looks good to me.
I think too many stars have exceeded the well depth -
they look over exposed.
Would 5 minute frames for luminance have been better with the same time?
A 10" f4 really grabs the light so it shouldn't need 15 minute exposures on such a bright target.
A 15 minute Ha frame would have been interesting though.

I can't wait to have a go on this one when my 10" f4 mirror arrives.

cheers
Allan

[NOMH (John)]

Lots of nebulosity in the Alistair! Looks great and you've done well with so few exposures.

I find my stars are always a problem for me. I think my exposures are fine for the target but the stars do over saturate and grow in size. I want to try shooting 30-60 second images just for the stars and then figure out how to swap them.

JB

[alistairsam]

Originally Posted by alpal

Hi Alistair,
looks good to me.
I think too many stars have exceeded the well depth -
they look over exposed.
Would 5 minute frames for luminance have been better with the same time?
A 10" f4 really grabs the light so it shouldn't need 15 minute exposures on such a bright target.
A 15 minute Ha frame would have been interesting though.

I can't wait to have a go on this one when my 10" f4 mirror arrives.

cheers
Allan

hi Allan,

I wanted the damn Jet, so went for 15 minutes. but also because I go by Ray's method of a target ADU for the background.
mine's around 3300 and with this 15min, its 3370 odd.
I think Ray's thread has some mention of not worrying about the well depth. can't remember.
This is the processed Lum
https://www.dropbox.com/s/ky05rj60vw...tack7.png?dl=0

Originally Posted by NOMH

Lots of nebulosity in the Alistair! Looks great and you've done well with so few exposures.

I find my stars are always a problem for me. I think my exposures are fine for the target but the stars do over saturate and grow in size. I want to try shooting 30-60 second images just for the stars and then figure out how to swap them.

JB

Thanks. I think they can be controlled when processing.

Cheers
Alistair

[Placidus (Mike and Trish)]

Hi, Alistair,

I can see the Herbig-Haro jet, so mission successful.

Might be worth posting the dropbox version as a 1:1 original pixels full resolution high quality jpeg, say compression set at 10 out of 12 PhotoShop "goodness" units (the file might be about a megabyte), rather than as a PNG.

I agree with you that for an object like the Trifid, the nebulosity, and something of especial astrophysical interest like the HH jet, is far more important than the stars. (For something like a globular cluster, the reverse would be the case.)

Keep 'em coming.

Best,
Mike

[alpal]

Originally Posted by alistairsam

hi Allan,

I wanted the damn Jet, so went for 15 minutes. but also because I go by Ray's method of a target ADU for the background.
mine's around 3300 and with this 15min, its 3370 odd.
I think Ray's thread has some mention of not worrying about the well depth. can't remember.
This is the processed Lum
https://www.dropbox.com/s/ky05rj60vw...tack7.png?dl=0

Cheers
Alistair

Hi Alistair,
I understand - yes - you got the jet so you achieved what you wanted.

My method of attack on this target will be to adjust the exposure time
so that the 2 center bright stars are clearly separated &
then I'll take as many multiples of that exposure time - as I can.

cheers
Allan

[Ross G]

Great looking photo Alistair.

Well composed with excellent detail and nice, smooth colours.


Ross.