M42 and combining images

[steviemac500]

This was taken last night. 25 subs @ 5mins, ISO 800. 20 darks, and 20 bias. EOS 1000D Guided with ZWOASI120 on my 200P although for some reason it's slightly off (I'm fairly new to it). I tried to do the core separately with subs at 1 minute length but I struggled to pull and nice data out of them and I also had difficulty combining the images. Is there a friendly tutorial out there?

 

[Herzy]

If you have photoshop you can simply replace the core. I'm not experienced with stacking so I wouldn't know how to get good results that way. Amazing picture nonetheless!

[PeterCPC]

This might help.

http://www.astropix.com/HTML/J_DIGIT/LAYMASK.HTM

Peter