Spent most of last night trying to get a reasonable image of M104. My polar alignment wasn't good so I stuck to short subs (15 secs) but stacked a lot of them (100+).
I've tried a few different processing options including Envisage stacked, RGB combine and Deep Sky stacker. Here's the Envisage Stacked (120x15 secs) and Deep Sky Stacker versions. There are a lot more subs (6 times) in the DSS version as I was able to pull together all the individual exposures. The RGB was a waste of time. The extra subs has improved the image compared to last weeks attempts.
The equipment is:
Imaging scope - 10inch Meade LX200R
Guide Scope - SkyWatcher ED80 piggy backed on LX200R
Guide Camera - DSI Pro (Mono)
Imaging Camera - Canon 20D DSLR
Depending on the FOV required for the target, I either use the 20D on the LX200R or the SkyWatcher ED80 and reverse the guide scope. I even use the DSI to take images using the Drizy function which takes nice pictures in its own right.
In PS, select all, then copy (contl C), then paste (contl V) . then you will have 2 layers . Set the top layer to "darken", select the shift tool, move it with the keyboard arrow keys in the desired direction to make the stars round (you are moving the top layer relative to the lower layer, any difference is "darkend"). When done (with round stars), select layers merge down to make a single layer again (thats the round star stuff done). Then, in yr case, select "colour select", and click on a star, then click on Add selection tool in colour select box and click on a few dimmer stars and then adjust slider until you have all the stars selected, then select modify and increase the selection by 4 pixels or so, then feather the selection by 2 pixels (to smooth further processing) You will notice all the stars are selected, but also the galaxy. Select lasso tool, then (with ALT key down, the cursor will show a - symbol) draw round the galaxy and realease the mouse key, the Galaxy will be excluded from the selection. What you have now is only the stars selected. Now select (Image, adjustments, desaturate) and all colour in the selection (stars) will be B/W. this last step is cheating, eliminates any colour in the stars to white.
All nicked from others smarter than myself . Ron wodaskis zone book springs to mind. And after fiddling with PS for a while, you get a feel for whats possible. I might add tho, that the better the data collected, the less you need of this trickery.
Agreed about this being a tough one to get right. It always seems to take much more exposure time than it should. Good work and I hope you can get your alignment sorted. Tripods can be frustrating creatures.
. Ron wodaskis zone book springs to mind. And after fiddling with PS for a while, you get a feel for whats possible. I might add tho, that the better the data collected, the less you need of this trickery.
