M20 - Trifid Nebula

[browndog (Ian)]

Image of M20 taken with 8" SCT with 6.3 focal reducer.

Autoguided using PHD and an 80mm achro + webcam. I used a 2" IDAS-LPS filter to reduce light pollution.

17 x 3min subs with an unmodified Canon 350d @ ISO800, taken from my suburban Perth location. Image stacked in DSS and post processing in PS.

This is my first image this year of M20.
(Having just completed my dew heaters I am pretty happy that I can now get dew free images.)

Any comments or suggestions greatly appreciated.

[leon]

Ian, other than a few bright reddish halo's it is a fine image indeed, it is always great to get the setup working the way you want,

Longer subs, 6-7 minutes, (your Hutech Filter will handle that OK) at a lower ISO, say 400, would probably give you much more detail, but this comes with time and experience, as I too have found out.

Did you use some darks, and flats with this image.

However, you have done a fine job, and keep at.

leon

[Peter Ward]

Originally Posted by browndog

This is my first image this year of M20.
(Having just completed my dew heaters I am pretty happy that I can now get dew free images.)

Any comments or suggestions greatly appreciated.

Ian,

Ok you are starting out. It needs some work.

DSLR's are not city friendly. They just don't have the dynamic range.

Go east of the Darling Ranges. Get some dark sky. Lose the LP filter. Coliminate the scope. Use in camera noise reduction. Learn how to take flats & calibrate the data. Take more time nailing the focus (2/3 out from centre field for a SCT works great). Nail the polar alignment (there is field rotation). Much longer subs to get more signal , say at least 5 minutes at ISO 400.

Stick with it. Not great yet. But has great potential.

Peter

[Terry B]

Constructive comment only.
The background stars are pink. It's alright to increase the red in the nebula but you need to keep the stars from becoming pink.
Good luck.

[Alchemy (Clive)]

practice makes perfect, and the processing will come in due course, if you havent got some form of book covering processing ...ie Photoshop Astrnomy by R Scott Ireland.... sanction a spending and then try some of the tricks/methods listed it will help.

meanwhile keep at it ..... you should have seen some of my older images .... yours is way better than them.

[skeltz (Rob)]

Keep at it browndog,theres a lot of good tips and help to be had here,as the boys above have explained.
Practice makes perfect.
HEY at least you have had some clear sky,s,can,t complain about that!!

[browndog (Ian)]

Originally Posted by leon

Ian, other than a few bright reddish halo's it is a fine image indeed, it is always great to get the setup working the way you want,

Longer subs, 6-7 minutes, (your Hutech Filter will handle that OK) at a lower ISO, say 400, would probably give you much more detail, but this comes with time and experience, as I too have found out.

Did you use some darks, and flats with this image.

However, you have done a fine job, and keep at.

leon

Thank you Leon for the comments and ideas. It is greatly appreciated. I will try the longer subs and lower ISO next time. I did use 10 darks and 10 flats with the image.

Originally Posted by Peter Ward

Ian,

Ok you are starting out. It needs some work.

DSLR's are not city friendly. They just don't have the dynamic range.

Go east of the Darling Ranges. Get some dark sky. Lose the LP filter. Coliminate the scope. Use in camera noise reduction. Learn how to take flats & calibrate the data. Take more time nailing the focus (2/3 out from centre field for a SCT works great). Nail the polar alignment (there is field rotation). Much longer subs to get more signal , say at least 5 minutes at ISO 400.

Stick with it. Not great yet. But has great potential.

Peter

Thank you Peter for the tips. The tip on focusing the SCT is one that I will be trying next time I get some clear sky's. I have found it difficult to get focus across the FOV. Will also check the polar alignment and collimation. Unfortunately with a young family it is not easy to get time to go to a dark sky site - but perhaps I need to try harder. Thank you for the comments and feedback.

Originally Posted by Terry B

Constructive comment only.
The background stars are pink. It's alright to increase the red in the nebula but you need to keep the stars from becoming pink.
Good luck.

Thanks Terry for the comment. Greatly appreciated. I didn't notice the pink stars when I posted. But now that you have pointed them out... Guess I will need to improve my processing skills.

Originally Posted by Alchemy

practice makes perfect, and the processing will come in due course, if you havent got some form of book covering processing ...ie Photoshop Astrnomy by R Scott Ireland.... sanction a spending and then try some of the tricks/methods listed it will help.

meanwhile keep at it ..... you should have seen some of my older images .... yours is way better than them.

Thanks Alchemy. Yes must keep practising.

Originally Posted by rpsastronomy

Keep at it browndog,theres a lot of good tips and help to be had here,as the boys above have explained.
Practice makes perfect.
HEY at least you have had some clear sky,s,can,t complain about that!!

Yes some great tips provided. I think that they will be useful? We had clear sky's here in Perth. Unfortunately it is now cloudy and rainy.