M33

[AstronomyUkraine]

This is a HaRGB combination of M33. Total integration time is 17 hours. With the light pollution I have here in Holland, I didn't even attempt collecting any Lum data.

 

4 hours each of RGB

5 hours of Ha.

 

[TerryMcK]

I know all about light pollution here too Brian. I'm in Bortle 7 and local LP from neighbours can be interesting. I bought a set of Antlia LRGB-Pro filters along with my SHO 3nm ones. I can use short 30 second subs on the RGB ones and get half decent results. L filter pointless for me. Can use it to focus with short 1 or 2 second subs on a star but that's about it.

 

Great image BTW. The Ha highlights well.

[MartinS]

Nice image there Brian, you have captured a lot of Ha. Do you merge the whole Ha with the red or just a portion using pixelmath?

[AstronomyUkraine]

5 hours ago, TerryMcK said:

I know all about light pollution here too Brian. I'm in Bortle 7 and local LP from neighbours can be interesting. I bought a set of Antlia LRGB-Pro filters along with my SHO 3nm ones. I can use short 30 second subs on the RGB ones and get half decent results. L filter pointless for me. Can use it to focus with short 1 or 2 second subs on a star but that's about it.

 

Great image BTW. The Ha highlights well.

Thanks Terry. My location is classed as Bortle 5, but I have an Led street light at either end of the garden. So realistically it could be Bortle 7 or 8.

[AstronomyUkraine]

4 hours ago, MartinS said:

Nice image there Brian, you have captured a lot of Ha. Do you merge the whole Ha with the red or just a portion using pixelmath?

Thanks Martin. I merge the Ha with the RGB combination using Pixelmath. I then use ImageSolver on the HaRGB combination, then apply SpectroPhotometricColorCalibration. The PixelMath formula I use is this. Seems to work very well. I have tried many different ways to combine Ha and RGB, this is probably the best I've come across. The numbers can be adjusted in the formula, to taste.

 

R. $T*.5 + Ha*.5

G. $T

B. $T

[Astrobdlbug]

Great image and reminder that as the main winter nebula drift westwards we start to see into deep space and galaxy season.

I have been considering a longer focal length 'scope to see what I could achieve, I too am classed Bortle 5 but the growth in housing and logistics warehousing in nearby Northampton is definately challenging that classification.

 

Also have you watched Adam Block's recent video about gradient removal particularly when you have a lot of space and a galaxy - interesting use of star removal and DBE - could be helpful for galaxy imaging under challenging  LP skies.

 

BTW - not saying your image has gradient, you seem to have removed any very efectively, but thought this would be useful place to highlight this processing  technique

 

Bryan

 

 

 

 

Bryan

[AstronomyUkraine]

1 minute ago, Astrobdlbug said:

Also have you watched Adam Block's recent video about gradient removal particularly when you have a lot of space and a galaxy - interesting use of star removal and DBE - could be helpful for galaxy imaging under challenging  LP skies.

Thanks Bryan. I was very selective in capturing the data away from the glare of the street lamps, so the gradient wasn't too bad at all. I saw Adam's process were he removed the stars before applying DBE, it looks to be a good alternative to the normal workflow.

[RaDec]

I reckon M33 is a tough subject to get as well as you have - 19 hours seems to have cracked it.

Kind of proves the point - there's no substitute for great data.

Super colours too.

Keith