first couple tries at AP, fully addicted now! Would love some feedback and tips

[Mattkeez]

Hey guys, I just wanted to introduce myself, as I'm sure i'll probably be spending a lot of time on here now that I've found it I first got interested in astronomy about 2 years ago, but after the painful frustrations of dealing with the learning curve, it sorta put a damper on my level of interest. I probably took out the scope about 4 times in the first 2 years. In any case, as the summer came this year, i was determined to get things going again. So I'm proud to say that I can actually do a decent polar alignment now lol.. Most people think i'm nuts spending so much time on this, but I'm very sure a lot of people can relate to the satisfaction you get from these "significant" achievements! My buddy and I literally screamed with joy and popped open some drinks when we got our first recognizable image from the ccd..  I was hoping you guys could give me some feedback and tips for how or where i need to look next to get better. I really don't know much about photography in general, but the various tutorials, especially from pixinsight have been helpful. It would be great if you guys have some tips and tricks for me! Especially regarding the noise on the m101 that I can't seem to get rid of.

m57 - I didn't do any processing on this one. I just stacked and calibrated it with dark & bias. 6x5min subs

m101 - I tried some processing using pixinsight but there's so much noise or pixelation, not sure what it's called, that I couldn't get rid of. this was 10x5min subs

My setup is:

scope: celestron edge hd 11

ccd: celestron nightscape

SS autoguider with maxim dl

[wxsatuser]

Thats a good start, I know the feeling when the first images appear.

Lots more subs for M101 would help with the noise, you only have 50minutes, try doubling the time.

Did you use darks, don't know the Nightscape but darks may help as well.

Try not to have the sky jet black, in processing go for a neutral grey.

I'm no processing expert may be someone else will popup and give you a few tips.

[Kirscovitch]

Very nice first attempts. Be careful though, imaging is super addictive!

[glowingturnip]

hi Matt, welcome, good looking images there.

Noise reduction in Pixinsight, I use MMT (Multiscale Median Transform) and TGVDenoise.  I've not yet managed to decide for myself which to apply first, so I usually do it both ways round and see which I like better.  I do it before stretching.

MMT - use 7 layers, on a small preview, and turn off layers 1-6.  The preview won't look like anything at all now.   However, if you then turn on the layers one at a time, the noise just pops out, it's like looking at a piece of ground glass.  Then you can fiddle with the noise reduction on that layer, I usually put the middle slider to 0.75, iterations to 3, and then move the top slider to as low as possible where the noise just winks out.  Then turn that layer off and do the next one, only do the first 4 layers.  Once you've got the params for each layer, turn them all on and apply to your image.

TGV is just trial and error, take a small preview of a noisy bit, set the iterations to 500, and play around with the edge param first so you can see that it is targeting the noise (if you're denoising a linear image, the edge param should usually be at least 1 exponent (the box on the right) less than the default level the tool gives you), but not to high otherwise it starts introducing bubble-like artifacts, then play with the amount.  Takes some practice.

Use a light touch with these, less is usually more !

Also, looks like a lot of the noise you have there is colour noise rather than signal - the arms are quite well defined, but there's a lot of smudgy brown noise inbetween.  Both the tools above can be applied to luminance and colour separately, so try that, you can be more aggressive with the colour noise reduction.

Cheers

[Mattkeez]

great, thanks for the tips. going to try that now. I'll keep you posted.

[Astrosurf]

They're excellent first pics! I can imagine the screams. I ran around at SGL4 showing people my first image, the Ring Nebula. I jumped around like a Jack rabbit when I got my first guided image, of M51. It's an amazing feeling.

Ditto what people said about more subs to increase data, and use of darks. You didn't say if you used darks for M101.

Alexxx