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Orion Neb - Just Can't Get it Right

Astrosurf

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Astrosurf

Astrosurf

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Hi all, I imaged the Orion Neb last night. Did 30 sec subs for the trapezium and 5 min subs for the neb. I only got 6 x 5 min subs as mist rolled in. But I can't seem to stretch the 5 min stacked subs in Photoshop without the red getting blown. I tried missing out the red channel in a few stretches, to try to bring out more nebulosity, especially in the top left (Running Man??) but the red still gets blown. I seem to be having difficulties with the red in my modded camera. I know the centre's over-exposed but I'll correct that with the 30 sec subs. Can anyone help with this image?

Alexxx

post-1704-0-69347800-1359883360_thumb.jp

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Jessun

Jessun

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Too few subs for you to be able to randomize the noice probably, and get that crucial S/N ratio up. All else looks great - exceptional layer work on Trapezium - so add 15 more! From there the effort/gain curve starts to really flatten the learned say.

/Jesper

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RikM

RikM

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The second process is beautiful Alex :)

As Jesper says, more of the longer subs will give you the headroom to stretch and sharpen the detail in the outer nebulosity but it is looking really good as is.

You should be able to use another night's worth of subs. If you use DSS, put them in a separate group, with their own set of flats and it will combine everything for you.

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Astrosurf

Astrosurf

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Thanks Rik. I'm feeling pretty chuffed with my efforts. I've got so much more detail than I have the last times I've imaged the neb. The guiding was twitchy, so the stars aren't very round, and I rushed so forgot the coma corrector! But I'm happy with the result now.

DSS is amazing.

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Jannis

Jannis

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Guess you've all seen too many M42s! :grin:

I've tried again with lots of selective stretching and a couple of layer masks. Please let me know what you think!

:eek:

*picks up my jaw from the floor*

wow, amasing! :)

Also very interested in how you processed it like that.

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Astrosurf

Astrosurf

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Finally got here! OK, wot I did in simple. Others will have done it differently and better, but I'm still learning PS:

I opened the long-exposure image and, because stretching further over-exposed the already over-exposed trapezium, I did a wavy selection around the area, feather 20px

Opened Histogram and brought the right-hand slider over to the left a tad.

To avoid the selection being obvious, I cancelled the one I'd done and did another one with a different wavy pattern.

Stretch a tad again - right-hand slider only in all cases.

Another section, a bit further out - I changed to feather 10px at one point as it was better.

Kept stretching a little and making different selections, some closer in, some further out as bits started to get over-exposed.

I often went back a step if I made a mistake and tried again.

I found the dark red area at the top of the neb, the bit with the hard edge, started to get over-exposed so did some sections on that.

Plus do selections on the bright part of the neb with a star in on the left of the neb, the one that looks like a witch's nose! (M43??)

Continue with this as you feel is right and don't worry about it being too over-exposed in the middle at the mo as the short-exposure ones will stop that. Just don't let the over-exposed areas spread.

When you're happy, the histogram should show the graph has stretched and moved to the right with a gap on the left hand side. I now moved the left-hand slider a tiny amount to the right to darken the background without touching the start of the graph.

Then I opened the short-exposure pic and selected out the trapezium as above but with feather 10 as you want to get in quite close.

I selected and stretched as much as I could using the above technique, selecting further out then in again. I think the 'nose' bit was OK but I can't remember!

Once you're happy you've stretched it comfortably, do a 'select all' then copy and paste it on to the long-exposure image.

Now for the layer mask. I went to Layer > Layer Mask > Hide All.

Click on the Layer Mask (the dark oblong) on the title of the short exposure in the Layers palette.

Choose the soft round brush tool and ensure the foreground colour is white

Get the brush quite large, at about 80-ish and set the Opacity to 10%.

Run the brush over the trapezium area and you'll see the short-exposure trapezium coming through. The white colour lets the hidden short-exposure image show through.

This is the hard bit which I could have done better. You need to do several iterations of the brush over the areas where you want the short-exposure image to come through, but graded at the edges. Used a succession of larger and smaller brushes. Each time you let the image come through more. Plus on the 'nose' bit and other areas as you like.

Once you're happy, you can add another image. I used my unprocessed stacked image, straight from DSS, to finally get the trapezium the right exposure. I just added it as another layer as before and another Layer Mask . Use a small brush here to get just the trapezium coming through.

Save this - you might want to play around with it some more!

"Save as" with another name and then go to Layer > Flatten Image.

I think that's it! I'm not that good at explaining. If you're not sure what I mean, just ask.

Alexxx

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Anweniel

Anweniel

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Hi Alex, the second attempt really shows a massive improvement on the first, really demonstrates what can be done with some nice processing. Struggling a bit with the processing too but not had much experience with PS, looked at some video tutorials that were very helpful in particular with removing my gradients without using any plugins. You seem to be on the right track though the image looks really great :D

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cp255

cp255

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That's nice. When I stretch in photoshop I like to use the shadows and highlights tool. It does a good job of bringing out the shadows and dimming down the highlights. Plus I can use it ot enchance the color.

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