Keyhole Nebula with Astro modded 350d

[RyanJones]

Hi all,

Firstly I’d like to send a huge thank you to Glenn (gb44) for offering me a trade so I could get my first Astro modified camera.

I’m amazed at the extra detail I could bring out when I had much better data to start with. I do miss the bright blues that shone through in the absence of Ha data but it’s a small price to pay.

This image was taken at home in bertole 7-8 skies.

56 x 90 sec @ iso 800
10 darks
10 flats
10 bias
Canon 350d ( astromoddified )
Astronomik CLS filter
Celestron C5 SCT

[ChrisV]

Great job on the camera there Ryan! And nicely processed.

[multiweb]

The on-axis data looks very good but you've been too heavy handed with your processing and the fine details have merged together into blobs. I reckon a repro will bring a nice center field.

[RyanJones]

Thank you Chris.

Hi Marc,

I'm pretty sure I know exactly what part of the processing caused that and it was right at the start but I didn't notice it until I was scrutinizing it after the fact. I'm still pretty happy with the look but I know there's quite a few problems with it as an image. Ill give it another go and I'll cut out that early step and see what happens. Thank you for the feedback :)

[xelasnave]

Looks good to me but it needs much more colour☺.

Now you will have to cool it☺
Great effort you will turn out some good stuff with your new camera.
I gather you are not using an eq mount???
Alex

[multiweb]

I'd say heavy noise reduction causes this kind of blobs. At your image scale, even if you keep the image a little gritty you should be able to extract some nice fine features in the center of the field as it is in focus. The rest of the fov can be cropped, that's not really where the interesting stuff is anyway.

[RyanJones]

Thanks Alex. Yeah, I found out the other night when it was 33 at midnight what temperature does to the image lol. Needless to say, that session went in the bin.

The colour I'm going to have to work on. The astro mod just makes everything red ! I'll have to work out how to bring the other colours through. All part of the game. I found the same thing on the opposite end of the scale ( blue ) when I first used my CLS filter.

I am now on an EQ mount by the way. A HEQ5 pro.

[RyanJones]

I used a tool in Photoshop called Minimum. I'm pretty sure that's when it happened. I'll have another go soon and see how I go.

[multiweb]

Did you use a star mask or applied it globally?

[RyanJones]

Globally. I actually used it to tone down the stars so they look more natural. Clearly creating my own issues.

[xelasnave]

Folk say that cooling a dslr with anything less than a cold finger is not good but I am sure when I ran peltie unit in a box with the camera in it the noise was not as bad...anywats you woyls rhink it must provide some benefit...maybe like the other night even a box set up may have dropped the temp just enough to help a little....
I plan doing a bix for my wide field set up ( nikon and 50 mm say) ...as I have a nice peltie unit laying around...a suitable box...reasonably long delays between captures ...but we shall see☺
Alex

[RyanJones]

It's the same as a lot of things in this game Alex. There's people who say things can't be done or won't work but I see that as an invitation to get creative. I have some ideas in mind but I've been lucky enough to acquire some new Astro gear recently so my mind is on that at the moment.

[Jasp05]

I've been tinkering with a cooler box for a dslr of late. Gets the temp down to 8 degrees from 27 degrees ambient. Haven't had a chance to try with the dslr in there just yet but given there will be a smaller volume of air to cool once the camera is inside, i think it should do a good job of keeping everything 15 to 20 degrees below ambient.

And given thermal noise halves for every 6 degree temperature reduction it should still make a noticeable difference.

[multiweb]

Ah ok, that would have eroded all your fine details. If you want to control your stars it's always good to generate a starmask. Startools is usually the easiest way to do that. There are also a lot of PS actions to manipulate star shapes such as Carboni action set and others. Easy to Google.

[RyanJones]

Thanks for the advice Marc. I have Carbonis tools for Photoshop but in the past I haven't had much success but having said that it wasn't with the data I have now. I'll give it another crack soon and see if I can get a better result. Thanks again for your input :)

[gb44]

Great to see my favourite DSO imaged.

For noise reduction using dithering is really very good and very easy. Do you use PHD2? If not then just do it manually, moving the mount a good 10-15 pixels over say 3 or more/10 subs.

For the colours other than red maybe try saturating just the blue and green channels. IP and PS can do so.

IP can do some star reduction.

If you want to try cooling I do have a spare peltier box. But it becomes pretty tedious. The cooling isnt controlled so the darks are not always right.
The box adds weight and you need more wires, and a pc power pack. It can cool the camera down too much and with a newtonian I was getting dew on the LPS filter...might be ok on the SCT. As per Gary Honis
http://dslrmodifications.com/rebelmod450d16c.html

Cheers
GlennB
and thanks for the mention

[RyanJones]

I'm not using any sort of guiding ( yet ). I will get to it though.
Regarding colour, I've tried the saturation of other channels but I can't seem to get the balance right .
As far as cooling goes, I'll get to that at some point too. Do people not find the fans vibrations causing issues or does it become an added extra because it causes ( true ) dithering ?

[gb44]

90 seconds unguided is pretty good. That's still going to allow you to manually move the mount between subs and eliminate a load of noise. Try moving just a few pixels and build up from there to what you find comfortable versus cropping the edge of the result. It will pay off. And reduce postprocessing noise reduction work.

With the colour balance being subjective just find a pleasing result that compares well.

With my cooler boxes I used rubber bands to hold the fans and eliminate vibration. Pretty essential to do something. I'm trying silicone now as the rubberbands are fiddly and dont last well.

Cheers
GlennB