M42 Orion Nebula - Stockport observatory

[planecrazy]

Hi all,

Bit of a closest viewer of this forum and the ability of the members who post here is fantastic.

Had an opportunity a couple of weeks ago to spend a fantastic evening at Stockport Observatory with some fellow ASSA members.

I just thought I would post my first real attempt at a layered image.
All my images to date have been comprised of a single exposure length. This is the first with multiple exposure times.

The evening was not intended as a imaging session; I was just out practicing my alignment and mucking around with guiding settings; so no dark, or bias frames were taken.

My setup is a Skywatcher Black Diamond ED80 as the primary scope.
Camera is a standard Canon EOS 700D. Mount Skywatcher HEQ5. Guide scope is an Orion short 80mm and the guide camera is the Starshoot Autoguider.
Image is comprised of:
Qty 10 600 sec ISO 800
Qty 5 180 sec ISO 800
Qty 1 15 sec ISO 800

Images were stacked using CCDstack 2 and processing done in Photoshop.

I know the image still needs work, but given the lack of calibration files I feel I have pushed as far as I dare. Has been a really good exercise in processing.

Regards,

Jamie

[Somnium]

well done Jamie, looks great.

[Peter.M]

Great image!

The only thing that I would change is the colour balance, I prefer to do this with the levels. At the top of this window in PS it lets you select channels individually (RGB). Your image has the blue channel stretched a little more than the green and red which shows in the histogram as the blue is further to the right than the rest of the peaks. If you stretch the green and red channels a bit more to match the blue, it looks a little better.

Keep up the good work .

[planecrazy]

Thanks for the advice Peter; will give it a go.

Jamie

[planecrazy]

Peter,

One question, to do the stretch do I adjust the mid point "bug" on the histogram?
I am guessing the black and white points should stay where they are.

Jamie

[Peter.M]

So moving the middle point will make the channel brighter or dimmer, then what you will want to do is move the left one (dark) so that the background is not so bright, that will require a small move to the right. To stretch a channel more, I itteratively brighten with the mid point, and then drag the black point up to just before the histogram starts. Doing this with individual channels, makes it possible to match the widths of the histogram peaks for each colour. So in your example the blue peak is too far to the right, and also too broad. To remedy this you could stretch the green and red channels by first making them brighter and then moving the black point to get it to line up with the blue histogram peak.

[Rigel003]

Very successful start Jamie. M42 is bright but quite a tricky object for your first stacking experience because of the large dynamic range. This has worked out very well. Don't be afraid of calibration frames. They're easy to do and really help.

[cazza132]

Wow - a very solid start! With some darks and flats, I am sure you would extract even more detail in the fainter areas. Just remember to take the darks at as close as possible to the same temperature as the ambient temps on site. My fridge gets some use for this :) Dark frame noise approx doubles for every 6 deg C increase in temperature.

One again, a very nice shot for your first go!

[SA_Dolphin_22]

HI mate, We definitely need another night like that up there again. Image is fantastic like other works you have completed and you know I am jealous. The bar is set high mr J :P so now I just need to get more data on some of mine see ya next week :D Mr Gorilla :thumbsup::thumbsup::thumbsup:.