Ladies and Gents,
Over two nights I managed to take a number of shots at 800iso of M42.
They consisted of:
10 x 20sec, 10 x 60sec, 3 x 3min, 4 x 5min and 5 x 10min.
Used DSS to stack, Processing was in CS3 and I used Noiseware to remove some noise.
Taken with a Canon 350D and ED80 and Orion Broadband DS Filter.
Image was cropped.
My main intention was to try and bring out the Trap' whilst showing the glory of M42 and as stated many times on this forum it is a difficult target to capture.
So here it is, please go easy on me and be critical as I have nothing to lose and a lot to gain.
Nice go at it Paul. Smoothing has been a bit vicious in Noiseware, and you've lost a lot of detail because of it. It's a fine balance between an acceptable amount of noise (while maintaining detail) and noiseless but featureless midtones.
I found that to bring out the Trap, I took a lot more short exposures (10 secs or so) and less long exposures. Try HDR to merge them too - it helps to tame the blowout by using the appropriately-exposed Traps from the shorter exposures rather than the massive highlight from the longer ones.
Just my 2 cents Paul. Some fantastic detail and nebulosity in there!! Worried your trap region is still a bit overdone though...
Thanks Rob for your input, yes the trap is overdone, its really hard to process something new, this is the first of many multi-exposures for me so I'm still finding my way, processing is also a steep learning curve but hey this is how you find out.
Quote:
Originally Posted by Omaroo
Nice go at it Paul. Smoothing has been a bit vicious in Noiseware, and you've lost a lot of detail because of it. It's a fine balance between an acceptable amount of noise (while maintaining detail) and noiseless but featureless midtones.
I found that to bring out the Trap, I took a lot more short exposures (10 secs or so) and less long exposures. Try HDR to merge them too - it helps to tame the blowout by using the appropriately-exposed Traps from the shorter exposures rather than the massive highlight from the longer ones.
Great effort though!
Thanks Chris, all taken in, I've seen some master images of M42 on this forum and trying to match is feat on its own even if you do have the recipe.
Nosieware is vicious, I will try and ease off on it and will process the image with less long exposures, this makes sense.
HDR - What software is this, downloadable? Sounds very interesting....
Not bad at all.. Tell me, Did you stack all the subs together? (ie, all the different exposure times?)
If so, thats not the best way to do it, as stacking will give you the average value of the pixels... hence the shorter exposures will kill out the detail in the longer exposures, and the longer ones will blow out the core a bit.... Its a good image none the less though..
Next time around, try stacking the sets of subs separately, then combining them together in photoshop using layer masks to gently blend them all together
a good guide on how to blend 2 exposures can be found here
Not bad at all.. Tell me, Did you stack all the subs together? (ie, all the different exposure times?)
If so, thats not the best way to do it, as stacking will give you the average value of the pixels... hence the shorter exposures will kill out the detail in the longer exposures, and the longer ones will blow out the core a bit.... Its a good image none the less though..
Next time around, try stacking the sets of subs separately, then combining them together in photoshop using layer masks to gently blend them all together
a good guide on how to blend 2 exposures can be found here
Alex
Thanks Alex, Yes I did stack separately and stacked every other way trying to bring out the Trap. Masks a dark area for me, I've actually been to that web site you linked to and followed step by step but got lost at Step 7, the tutorial states 'Step 7 - Open a New View of the image
VIEW > NEW VIEW will open up a copy of the composite. Place it on the left.
This is were I got lost, is this CS3 friendly or is it an older version they are referring to?
Hi Paul. I have to agree with the other comments but it still is a nice image. Don't be fooled M42 is one of the hardest targets in the sky and will keep most of us busy for our lifetimes trying to get it right. There are a few methods that can be used to retain detail in the tra whilst still maintaining the detail in the nebula.
1 HDR Merge in photoshop.
2 Follow the details in the link AlexN posted.
3 A program called EasyHDR which is used a lot by Avondonk on this forum.
4 Then this link which is one of Jerry Lodrigus' methods and by far the easiest to try. Much easier than his other method posted by Alex. http://www.astropix.com/HTML/J_DIGIT/COMP2.HTM
Keep at it like the rest of us. Time and perseverence brings results.
Hi Paul. I have to agree with the other comments but it still is a nice image. Don't be fooled M42 is one of the hardest targets in the sky and will keep most of us busy for our lifetimes trying to get it right. There are a few methods that can be used to retain detail in the tra whilst still maintaining the detail in the nebula.
1 HDR Merge in photoshop.
2 Follow the details in the link AlexN posted.
3 A program called EasyHDR which is used a lot by Avondonk on this forum.
4 Then this link which is one of Jerry Lodrigus' methods and by far the easiest to try. Much easier than his other method posted by Alex. http://www.astropix.com/HTML/J_DIGIT/COMP2.HTM
Keep at it like the rest of us. Time and perseverence brings results.
Nice image just the same.
Thanks Doug for your kind words...mate it is a hard one to bag and the learning curve is great.
When I saw your recent image I thought Wow! I will have a go at that, I may not come close but I will have a go. Maybe I went overboard on the images.
Quick question: Do I process before Layers or process after?
An absolute stunner, love the process, looks great in my opinion, I like the wispy nebula look more than the razor sharp stars in the trapezium etc.
Well done!
Cheers
Chris
Thanks Chris, I've been fiddling with this image for some time and I'm on the verge of sweet goodnights with it. I'll give it a rest of try again later.
I suppose it does have an air' of satisfaction surrounding it.
Here is the first image from the first night.
Using 10 x 20sec, 10 x 1 min, 3 x 3min and 4 x 5min all 800iso
Paul
Last edited by peeb61; 21-01-2009 at 11:14 AM.
Reason: updated with exposure information.
10 minutes will over expose the core, but you still wont get the deep dusty areas surrounding M42 in less than a 15 minute exposure..
The way to go with M42 is lots of subs, at many different exposure levels..
My best M42 to date consisted of:
10x10sec Ha subs
6x30sec Ha subs
8x10min Ha subs
17x4min colour subs
40x10sec color subs
Each of these sets of subs were stacked separately, giving me 5 .tif images. I then input the 5 tiff images into Registar, which countered the rotation and offset of each of the 5 resulting images, and saved the 5 new .tif files
Using photo shop I processed each of the tif files individually to its own merit (Very gentle stretching on the shorter subs, to retain the cores detail and the trapezium, and rather agressive stretching on the longer subs to bring out the fainter whisps of nebulosity that are not commonly seen..)
Still in photo shop, I layered the 30sec Ha tiff with the 10 min Ha tiff to create the final Ha image. which after layering, was evenly exposed from the very faint whispy details surrounding M42, right the way through to the 4 stars in the trapezium.
I then layered the colour Tif files together, creating an evenly exposed colour image.
Finally I layered the Ha image (black and white) into the final colour image as a luminance layer.. The Ha data showed much more fine detail than the colour one, due to its longer exposures, and hence forth, using it as a luminance was the best way to get the faint details to stand out in such short colour exposures.
Generally speaking, the longer the exposure time, the better the final image.. and the best exposure time for 90% of targets is the longest exposure time your setup can do before tracking errors occour..
M42 is a deceptive target.. because its big and bright, many people begin to thing that its an easy target to image... Whilst it is very easy to capture nebulosity in this area due to its brightness, it can be VERY difficult indeed to take an image of m42 that is great. This is due to its incredibly varying dynamic range... It contains everything from very dark dim areas of dust to extravagantly bright emission nebula.. Thanks to its composition, it is nessacary to take many sets of data at varying sub duration in order to give your image the depth required to show off everything this stunning target has to offer...
There are some images I've seen of M42 that have MASSIVE data sets.. the best I've seen had 50x5sec, 50x10sec, 50x30sec, 20x60sec, 10x3min, 10x5min, 10x10min and 10x25min...
That is one hell of a task just to capture that sort of data.. then to process it all... Its not for the faint hearted...
You've done well in your attempt, and Im sure you will improve on this in the coming months!
M42 is all in the processing... Capturing data is easy, Processing it to get a good result is very difficult.
10 minutes will over expose the core, but you still wont get the deep dusty areas surrounding M42 in less than a 15 minute exposure..
The way to go with M42 is lots of subs, at many different exposure levels..
My best M42 to date consisted of:
10x10sec Ha subs
6x30sec Ha subs
8x10min Ha subs
17x4min colour subs
40x10sec color subs
Each of these sets of subs were stacked separately, giving me 5 .tif images. I then input the 5 tiff images into Registar, which countered the rotation and offset of each of the 5 resulting images, and saved the 5 new .tif files
Using photo shop I processed each of the tif files individually to its own merit (Very gentle stretching on the shorter subs, to retain the cores detail and the trapezium, and rather agressive stretching on the longer subs to bring out the fainter whisps of nebulosity that are not commonly seen..)
Still in photo shop, I layered the 30sec Ha tiff with the 10 min Ha tiff to create the final Ha image. which after layering, was evenly exposed from the very faint whispy details surrounding M42, right the way through to the 4 stars in the trapezium.
I then layered the colour Tif files together, creating an evenly exposed colour image.
Finally I layered the Ha image (black and white) into the final colour image as a luminance layer.. The Ha data showed much more fine detail than the colour one, due to its longer exposures, and hence forth, using it as a luminance was the best way to get the faint details to stand out in such short colour exposures.
Generally speaking, the longer the exposure time, the better the final image.. and the best exposure time for 90% of targets is the longest exposure time your setup can do before tracking errors occour..
M42 is a deceptive target.. because its big and bright, many people begin to thing that its an easy target to image... Whilst it is very easy to capture nebulosity in this area due to its brightness, it can be VERY difficult indeed to take an image of m42 that is great. This is due to its incredibly varying dynamic range... It contains everything from very dark dim areas of dust to extravagantly bright emission nebula.. Thanks to its composition, it is nessacary to take many sets of data at varying sub duration in order to give your image the depth required to show off everything this stunning target has to offer...
There are some images I've seen of M42 that have MASSIVE data sets.. the best I've seen had 50x5sec, 50x10sec, 50x30sec, 20x60sec, 10x3min, 10x5min, 10x10min and 10x25min...
That is one hell of a task just to capture that sort of data.. then to process it all... Its not for the faint hearted...
You've done well in your attempt, and Im sure you will improve on this in the coming months!
M42 is all in the processing... Capturing data is easy, Processing it to get a good result is very difficult.
Keep at it mate, and keep those exposures long!!
Alex, your a gentleman and a scholar.
Thanks for your time putting this tutorial together, it makes a lot of sense.
After seeing Garyh's image of M42 just recently which I might add, totally blew me away the longest sub Garyh took was 4 minutes and lots of them so I sort of put 2 and 2 together.
As you say its all to do with exposures and how they are processed.
Mate its a bendy road for me and my wagon has only three wheels but I'm getting there.
When there's cloud about and I can't get outside I will endeavor to do some repro's and work some of this magic you talked about.
a dark area for me, I've actually been to that web site you linked to and followed step by step but got lost at Step 7, the tutorial states 'Step 7 - Open a New View of the image 
