M42 Atik314L 0.8 FR ZS66

[Fay]

This was my first image regarding about 6 different length subs, from 30 secs to 600 secs. I really have not got the hang of layer/masks, I have been on it all day, as I have a Canon M42 version as well. There are a lot of things wrong with it, but I need a good couple of hours tuition. I will never do one of these again, life is too short
Last night, looking like someone who had been buried in permafrost for 1000 years, I set the camera up to do 60 mins worth of subs, went indoors, came back out after 1 hour to see I had left the cap on the scope. Hence about 30 darks!!

[Rocket Pooch]

Fay I should not laugh, but thats bloody funny!

Anyway, maybe when I'm back from Wales this week I'll pop over and we can re-process the image, it was better than what you have put on the forum.

[Mac]

came back out after 1 hour to see I had left the cap on the scope. Hence about 30 darks!!

not to worry, you can start building up your dark library now.

[Fay]

Chris, are you talking about my image or my experience being funny?

I have just restacked using only the 300 sec subs. I think it is a bit better, although trapezium still a bit bright. I will put it on.

[Fay]

I think this ia a bit smoother, not so much drift,  15x300secs, I think. Tried to do  a couple of spikes on those 2 big stars but actions would not do it.

[Daniel]

Lovely image Fay, you've captured a lot of faint outer nebulosity, I guess that's what you get for 300s subs. Did you do any shorter subs to layer mask over the trapezium, or can you under-process another copy of the image before you stretch it?

Daniel
:O)

[Fay]

Daniel, you name it, I did it! I have never done it before & got confused. Also not sure what the shorter subs should look like. I suppose I could have a go at under processing the same image. Daniel, how do you choose which part of the mask you want to use? I seem to be using all of it.

[MarkS]

The second one is much better.  You are picking up lots of faint wispiness.  But the trapezium area is burnt out.

Mark

[Fay]

Yes, I do have the shorter exposures but when I add them, it looks muddy. I am not getting the processing correct. I understand the basic concept of layer/ masking, but need time on the rest.

[Whitters]

Lovely image Fay, you will have to start taking shots around the outside and compose a moasic. The nebulosity around M42 goes on for degrees.

[Fay]

Thanks Paul I am just on my 4th day of trying to master sorting out the Trapezium  Can't stand it no more!!!!!

[MarkS]

Fay,

I had a go at this myself last night in Photoshop. The steps are as follows:

1) Start with two images - one where the trapezium is burnt out (the bright image)and one where it is not (the dark image).
2) Copy and paste the dark image onto the bright image - it needs to appear as an extra layer.  You might have to duplicate the dark image as a layer on the bright image instead.
3) Select the dark layer and add a mask to it - there's an icon for adding a mask. The mask should appear just to the right of the dark image in the layers.  The mask will be either totally black or totally white.
4) Copy the bright image then activate the mask by holding down the "Alt" key and clicking the mask.  Paste the bright image into the mask - it will appear in black and white.  Now Gaussian blur the mask.

That's all there is to it.  Make sure both layers are visible (showing the eye symbol).  Now you can tweak it to taste.

If you are still stuck, I can send you an example PSD file tonight.

Mark

[Fay]

Thanks Mark, I have got that far. It is the bit where I don't want all the darker image to appear in the original, the paint the background black bit, & paint the bit you want to appear, white. When I add my darker bit, it is muddying up the original.

[Mike]

Excellent M42 Fay!

[MarkS]

Fay,

The mask should take care of that all on it's own - once you have pasted the bright image into the mask.  Where the bright image is burnt out, it will appear white in the mask - so this is where the dark image is substituted.  Where the bright image is dark, the mask will be black and so none of the dark image is substituted.   Where the mask is grey, you'll get a proportion of the dark image and a proportion of bright image.

There should be no need to manually paint black and white bits in the mask.

Mark

[Fay]

Mark, my mask is white checks with a whiter bit in the middle & a light grey surrounding it. The white bit, when superimposed, seems to be inverted, a grey colour not over exposed white.

[MarkS]

Fay,

I've put an example at http://homepage.ntlworld.com/the_shelleys/Astronomy/neb4.psd

Mark

[Fay]

Mark, I will have another go at this tonight.
Now what I get is, a white check mask with a whiter bit in the middle, the burnt out centre of the bright image, but the rest of the mask is still white not black, so when I process, it alters the whole of the main image, not just the centre.

[MarkS]

Check out my example - that will tell you what it should look like.

[Fay]

Thanks Mark. I got the dark one onto the main image, but when I do curves or any other processing, the whole image changes not just the centre. 

[Fay]

I think I have hit on my problem....................have not been aligning the long exposure with the short!!!!!!!!!!!!!!!!!!!!! Hence, that is why I get a muddy grey in the trapezium area, because it is a different part of the image showing through!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Can anyone tell me the easiest way to align the main image with the masked one.........PLEASE!!!!!!!!!!!!!!!!!!!!!!! Before I go madder than I already am

[Rocket Pooch]

highlight a layer, set the transparency to 50% do CTRL+T then move it about with the arrows, when your comfortable with alignment press enter.

or align them in maxim, aa or whatever your using.

[Mac]

another easier way is to rearange the layers so the layer you want to move is on the top, You can always change it back after.
then change the dropdown from normal to difference,
and then move the layer, if everything is in alignment the image will be Jet black.
Even one pixel out it will show the difference between the two layers.


Here are two layers one ontop of the other, only the top one is out by 1 pixel.


By changing the top layer to difference instead of normal, it shows you the difference between the two images,



If you them move the images around the differences are always higlighted, untill they are aligned completly.
Then the image is black.



all you do is then change it back to normal, and drag the layer to where you want it.

Dont forget, the two images will never align perfectly!!
as they were taken at different times, ect,
but if you look at two stars, you can align them over each other, ect.

[Fay]

Thanks Chris & Mac.
My two images look like they need a small rotation.............eek!

Mac that is very informative, I will have a go anyway