M42 My best yet. - Page 2

davidpretorius · #21 02-12-2005, 08:50 PM

Quote:

Originally Posted by Striker

Can someone please explain whats wrong with my processing of Trevors Orion

i am not in that quandry, but see it that i also like a black background and will always set that to zero. the trick is to combine the "detail" of rob's with the darker sections or yours and mine.

i like his thinking on masks and having a few different processed ones to bring together.

i believe there to be noise between running man and the nebula proper, but he has the true detail showing left that is not noise.

that is trick (art) to combine both images!!

#22 02-12-2005, 09:25 PM

In regards to background. This is my interpretation. Although black or
preferably near black backgound skies are nice for planetary imaging, I
find it helps make low contrast objects and the detail on them standout
a lil better. However aiming for total black background on dso's I feel
tends to look a lil unatural to me. Also Orion is getting near the plane of
the milky way. There is the ever present background stella glow.

On the other hand, I was trying to bring out detail and was only willing to
spend 30 minutes on it, given a few hours+ plus things would be different.

regards,CS

#23 02-12-2005, 09:36 PM

Quote:

Originally Posted by davidpretorius

i am not in that quandry, but see it that i also like a black background and will always set that to zero. the trick is to combine the "detail" of rob's with the darker sections or yours and mine.

Probably a dark frame substraction would work better, but give it a go and
see what you come up with.

regards,CS

davidpretorius · #24 02-12-2005, 09:41 PM

don't worry, once i get tracking next week and can get this modified toucam to do some work, the dark frames will be out in force.

it is a real art form, as you say 30 mins is not enough. The DSO guy must put days and days into it!!! There is no magic button!

Striker (Tony) · #25 02-12-2005, 10:25 PM

My next image I am going to do 2 version's....then go from there.

Processing can take some time but it's great for wet weather.

Itchy · #26 02-12-2005, 10:54 PM

Quote:

Originally Posted by davidpretorius

i am not in that quandry, but see it that i also like a black background and will always set that to zero. the trick is to combine the "detail" of rob's with the darker sections or yours and mine.

i like his thinking on masks and having a few different processed ones to bring together.

i believe there to be noise between running man and the nebula proper, but he has the true detail showing left that is not noise.

that is trick (art) to combine both images!!

Interesting. I do everything I can to avoid making the background black. Mainly because the sky is not black. If anything it is a very deep blue, and I try to set my background accordingly. The problem is that the faint detail we are trying to bring out is very close to the background. If you darken the background to zero, you are "clipping" the image and throwing out detail. The tradeoff of course is noise. The best way to overcome that is to take more and longer exposures. The more exposure you have the better the signal to noise ratio will be and the easier it is to bring out the detail without raising the noise floor too high.

cheers

davidpretorius · #27 02-12-2005, 10:58 PM

spot on itchy, of course that is why you pros take 10 x 20 mins etc, the 10 reduce the noise along with darks.

i feel rather dumb at the moment!!!

but happy, it is starting to make sense!

TidaLpHasE · #28 03-12-2005, 01:40 AM

Thanks all for the processing tips and techniques, i myself prefer a darker background with less noise/less detail, than more noise more detail.

I would prefer to lose a little detail for less noise in my images. I will try for longer and longer exposures to get the detail, and process as much noise out as can be.

Tony, there is nothing at all wrong with your processing, and as stated i prefer the way you have adjusted my image, and can live with a little less detail, that being said, i also like all the others attempts at bringing out detail, Robs effort shows just how much there was in the image, it was hidden.

I would love to expose M42 for 5-10 minutes onto the cmos, but think it is asking too much of just polar alignment and the EQ6 ?

Any tips on getting extra long exposures Itchy? would i need to buy a guiding camera/software/laptop

davidpretorius · #29 03-12-2005, 08:42 AM

Trevor, a request.

how easy is it to say take 10 or 15 shots at say 60sec or even 120 secs and then say a 10 really short ones at an exposure time so that the trap stars are not burnt out.

That way we can start to stack em to get rid of noise, and thus be less agressive with the darkening and also have nice definition of the trap.

This is all based on http://www.astropix.com/HTML/J_DIGIT/COMP2.HTM and http://www.astropix.com/HTML/J_DIGIT/LAYMASK.HTM

If you don't mind taking them, there seems to be a lots of guys appreciating the opportunity to test their processing skills on what are very good images!!

I can put zipped up images on my webserver in larger image sizes so we have better quality images to start the processing off and guys can download from there.

These images are a pleasure to work with: Thanks!!

Striker (Tony) · #30 03-12-2005, 09:01 AM

Thanks Trevor for allowing us the opertunity to play around with your shots.

Hopefully I can take some wide field shots tonight.

regarding number of shots...dont even stop at 10-15 shots at 60 seconds...if you have the time trevor...do 50 shots...when I did the M20 I took about 80 shots at 30 seconds...and then took the best 30 or 40 I think...cant remember too long ago.

If time is not a factor...just keep taking them.

#31 03-12-2005, 09:21 AM

yeah! thanks Trevor for letting us play : )

If you guy's would like to do some serious image processing, Why not (if you
have Photoshop 6 or later) download Fits liberator. And then go download
Hubble data from the Digital Sky Survey. You can do you own interpretations
of all those amazing images the Hubble has been throwing at us for years.
The only draw back is huge file size downloads... I've had one image at near
1/2 a Gig with all three RGB layers.

regards,CS

Itchy · #32 05-12-2005, 06:26 AM

Quote:

Originally Posted by TidaLpHasE

Any tips on getting extra long exposures Itchy? would i need to buy a guiding camera/software/laptop

The ideal way to do it is to use a CCD and a guide scope, along with a laptop and guiding software. An auto guiding camera is another option if your mount is compatible. If dollars are an issue (and when aren't they?) you could do what Tornando33 and myself do. ie manually guide. For that you need an illuminated reticle eyepiece and either a guide scope or an off-axis guider, and considerable patience.

Cheers

TidaLpHasE · #33 05-12-2005, 08:50 AM

Thanks Itchy, i will look at an auto guider, depending on the $$ of course.

I got another session in this morning, and from what i could tell by the lack of twinkle in the stars, the seeing would have been easy 8-9/10.

Polar aligned, then again and again, third time lucky, i aimed at Orion again and took a few images.

1.5-3 minute exposures at between 400-800 and 1600 ISO.

Got a bit more detail in the images, both images are a stack of four.

Happy for people to play with these images, i am limited at the amount of detail i can pull out of them.

Dennis · #34 05-12-2005, 07:35 PM

Very nice images Trevor. Great efforts by the "processing gang" as well; in particular, Rob's version which shows incredible detail.

Cheers

Dennis