2nd try at M27

[rikyuu]

Well, I was blessed with another clear night last night, in fact I think I could just see the Milkyway, which is a first for me in the UK.

So I had another crack at M27 and autoguiding. This time I tried to polar align better, but ended up messing up the centering of the polar scope so wasn't sure how good I'd got it. I also tried guiding with the C80-ED this time at f=600mm (instead of the 122mm lens).

The guiding turned out to be very good on this occasion, pehaps just luck or maybe the C80 helped. Anyway, much less elongated stars and no problems with DSS stacking them. 9 x 5min subs, ISO800, cropped to remove dust and amp glow, but as my camera is still connected to the scope, I will attempt some flats and darks tonight (if the temp is similar for the darks).

So here's my new M27, a bit more detail coming through compared to last time.

[rikyuu]

one thing I notice compared to other M27 images is that I'm missing any red details towards the centre, it's only on the very outer edges. However, if I increase the red channel, the background becomes too red. Any ideas?

[Catanonia]

Is you 300d modified?

9 x 5min subs is not enough. Get loads more and you will start to see detail.

Here is an example of a modified EOS 350D with 5 min subs for 90 mins in total and start to see more detail. This was shot in less than perfect conditions with refractor ED120 running 900mm and F7.5

I would definately take loads and loads more subs and look to getting your 300d modified.

Banging up the red channel will not help. I often see shots like yours with the blue, very blue. Try turning down the blue channel a bit, also go back to the stacked tiff and try auto levels. Sometimes it works really nice, most times though it doesn't.

Can you post a link to your tiff so I can have a play with it ?

Great image and base to expand from though.

[rikyuu]

hi Catanonia, thank you for your comments, I'll keep adding subs to it to bring out the colour. Unfortunately my 300d is unmodified, so is at a disadvantage when it comes to the reds.

Here's a crop of the tiff, stacked in DSS with median stacking. I would be very interested to see what you can do with it.

Many thanks

Stargazers Lounge - rikyuu's Album: M27 - Picture

[Catanonia]

hi Catanonia, thank you for your comments, I'll keep adding subs to it to bring out the colour. Unfortunately my 300d is unmodified, so is at a disadvantage when it comes to the reds.

Here's a crop of the tiff, stacked in DSS with median stacking. I would be very interested to see what you can do with it.

Many thanks

Stargazers Lounge - rikyuu's Album: M27 - Picture

when my processing is done on my current image, will take a peek for you.

mmm can't save the pciture properly. Can you email to steve.allan at gmail.com

Cat

[rikyuu]

Thanks Cat, you have an email

[Catanonia]

No worries got the file eventually with a bit of hacking

edit : ah, much better, got it in email.

[Catanonia]

Here you go mate. Had to push the data a little, probably a little too much, but you can start to see the red coming through.

Compare to my image and you can see how an addition 1 hour data and a modded dslr can really help without forcing you to add false colour by upping levels.

Also try not to push the colours too high, makes the images look very fake as they are not as blue in comparison to the pictures you see.

[rikyuu]

Excellent thanks, I can see the red detail coming though. You're right, I was pushing up the colour too much to try and colourise it, but it was making it too blue and bringing out noise. I guess I need at least twice as long as you with my unmodded 300d, so I will try an push the subs up to 10 minutes if my tracking is good again and try and get another hours worth.

Many thanks for your help and advice.

[Catanonia]

no worries, but don't push to 10 mins, your ickle dslr like mine will struggle with noise. Don't forget to let the ccd in the dslr cool down, say 1 min between subs, again to help with noise.

Stick to 5 - 8 min subs and plenty of them. Your guiding isn't bang on yet and 10 mins will cause drif too

Good luck mate, it is a great base to add to.

[rikyuu]

had another little play based on 'Cats' advice and demo and I think this is a bit more like what I should be aiming for, although I can't quite match your processing expertise Cat!

[Catanonia]

Dude that is 1000% better and more natural. Congrats

Now as a certian Physco told me on this forum, get out there and add more data to it

[MartinB]

I think half way between the first and the last Rik. I like the colour in the first but the last one definitely shows that you have plenty of red Ha in there.