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View Full Version here: : Close up M42 C11 + QHY8 - Reprocessed image added.


AlexN
06-10-2008, 05:43 AM
After quite a few hours with guiding issues, I managed to get it 90% sorted and under control, many thanks to Doug (Hagar) for a lot of hints and tips...

This is a mere 20 mins of data. Comprising 2x4min subs, and 6x2min subs..

A little tweaking in photoshop with my lack of sleep eyes, so it will be done again.. :D but had to post it, because im rather happy... :)

M42 @ 1700mm

Alex.

Hagar
06-10-2008, 10:08 AM
Nice Alex. The C11 certainly grabs a lot of light for these short exposures.
Well done.

strongmanmike
06-10-2008, 10:21 AM
Excellent Alex, colour looks beautiful and you handling of the trap region is great! Your sleepy eyes have done their job.

Mike

AlexN
06-10-2008, 01:02 PM
Thanks guys, And thanks again Doug for tips during the night..

I think I found the problem when I started packing it all up.... The RA axis lock was not as tight as it could have been... Ie - I took the QHY8 off the C11 and the mount started to wander down on the opposite side... I bet that could have caused problems with guiding/tracking.

TrevorW
06-10-2008, 01:22 PM
Great shot Alex I took my first shot of a nebula the other night and was amazed with some help how suttle detail can be extracted byt how the data is processed, sure is a learning curve


Cheers

AlexN
06-10-2008, 07:50 PM
Thanks Trevor..

Just prior to leaving for work I started a re-process with fresh eyes... I managed to pull out a bit more detail by very gently stretching the data a little bit more, gave it a touch more saturation and equalized the histograms, added a slight unsharp mask which really made the detail through the darker nebulosity pop... The trap is still very tame and natural looking... I'll finish it when I get home and post it up + a link to a full size image...


Overall so far I am VERY happy with this image, Its just a shame that only two of the 10 4 minute subs I took came out any good... there were a few fairly strong gusts of wind that came through, which may well have been to blame, as I think the C11 + Megrez 102 and all the added extras are really pushing the EQ6 Pro...

Thanks again for the comments guys... Much appreciated.
Alex.

winensky
07-10-2008, 11:49 AM
You have every right to be happy with this one. That is a lot of light for the exposure time! great processing and As you say, the dark regions really stand out and provide great depth.

Matty P
07-10-2008, 01:29 PM
Great work Alex, you have got to be happy with that.

Lovely detail and colour especially within the Trap.

Very well done. :thumbsup:

AlexN
07-10-2008, 07:33 PM
Thanks Matt and Matt... I am stoked...

gregbradley
07-10-2008, 07:52 PM
A wonderful image.

Greg.

AlexN
08-10-2008, 01:00 AM
I got around to finishing that re-process I was talking about..

I think its better..

Garyh
08-10-2008, 08:43 AM
Much more detail showing in the repro :thumbsup: Maybe a little green cast to it? compared to your original post which I think has spot on color!
Good one Alex!

gregbradley
08-10-2008, 09:04 PM
I prefer the original as the stars seem oversharpened.

To get detail in the object yet not overdo the stars you use a technique called selective sharpening using layers and masks in Photoshop. There are free tutorials on how to do that on the net.

Here is a quick summary:

1. Make a duplicate layer
2. set it to overlay mode
3. use high pass filter
4. layers/masks/hide all
5. select brush and brush the areas you want sharpened.
6. layers/flatten layer

Greg.

AlexN
08-10-2008, 09:44 PM
Thanks for that Greg, I'll give that a go when I get home from work...

What I had been doing was selecting everything except for the stars, applying an unsharp mask to the whole lot, then deselecting the stars and thats it.... Seems a fairly hack way to do it, but it works (sometimes...)

gregbradley
08-10-2008, 11:12 PM
I don't think there's any hack way only what is effective. That works too.

Did you sharpen the stars earlier in your processing?

Perhaps they are black clipped in the early processing. A little bit of gaussian blur on the stars only may soften the slightly harsh look.

Its kind of a minor thing though from an overall very pleasant image.

Greg.