Editing Images

Benno (Ben) · #1 05-06-2007, 08:54 PM

Hey guys/girls,
As mentioned earlier I'm new to this and in particular Astrophotography. Ive taken some photos of the Southern Cross and a few clusters, but am unable to work out how to give em a bit more detail and clean them up a bit through Photoshop CS2.
Just wondering if there are any programs out there that can be used for astrophotography in particular or is it more of a layer on layer kinda thing?
I have a Canon 400D with both the 18-55mm and 75-300mm lens.
Any help is much appreciated.
Benno

RAJAH235 · #2 05-06-2007, 10:04 PM

Benno, Hiya n Welcome

...see the Projects & Articles section >
http://www.iceinspace.com.au/index.php?projects

iceman (Mike) · #3 05-06-2007, 10:11 PM

Hi Benno

Most of what you'll use is in photoshop. Why not post a few of the images and let us help you to get the most out of them?

Were they on a fixed tripod or tracked using an equatorial mount?

ballaratdragons (Ken) · #4 05-06-2007, 10:15 PM

Or you can use a nifty program (a plug-in to PhotoShop) that helps process images in some clever ways:

http://actions.home.att.net/Astronom...l_Version.html

Benno (Ben) · #5 06-06-2007, 12:06 PM

thanks ill post a few tonight and let you guys loose on them.
they were all taken on a tripod mount too.

Terry B · #6 06-06-2007, 12:26 PM

A powerful and free programme is Iris

Benno (Ben) · #7 06-06-2007, 05:48 PM

here you go
Benno

rmcpb (Rob) · #8 07-06-2007, 01:30 PM

Benno,

I had a very quick play with your first image in Photoshop, adjusting the curves, brightness and contrast and ran a sharpening filter. Then the whole thing was whipped through NeatImage to removes some of the noise.

Lots of info in there to play with.

Have fun

Benno (Ben) · #9 07-06-2007, 08:45 PM

thanks man, ill try some of that with a few other pics i got.

ballaratdragons (Ken) · #10 08-06-2007, 02:19 AM

Here ya go Benno, I had a play with one of them in PhotoShop

g__day (Matthew) · #11 08-06-2007, 09:31 AM

Photoshop CS2

Run iterations of Levels and then Curves first to tweak the signal to noise ratio, then run your filters.

In levels you want to adjust the pointer to the left of the histogram to just start protruding into the data inside the histogram- this throws away all useless data to dark to see (noise).

If the dark sky becomes too bright then shift the mid point of the histogram to the right slightly.

Next you have to strech the histogram to give yourself more spectrum to play with - this is where curves come in. Boost the lowest intensity light more than the brightest - but in doing this you boost noise too. To do this shift the 45 degree line upwards from the bottom lower left a small amount by adding 1-2 control points. Think of this curves as being 4-5 zones. You want to brighten data in zones 1 2 and 3, and possibly dim data in zones 4 and 5 - the brightest stars in the picture.

Then you re level to compensate for boosting noise (e.g. light pollution) as well as data in the dimmest portion of your shots.

Benno (Ben) · #12 14-06-2007, 09:12 PM

hey guys thanks for all the replies and tips and the efforts you made at the pics i supplied. ill had to jump on photoshop and see what i can do.
question: how do you get the diffraction spikes? is that a plug in you can get?
Benno

ballaratdragons (Ken) · #13 14-06-2007, 09:32 PM

Quote:

Originally Posted by Benno

question: how do you get the diffraction spikes? is that a plug in you can get?
Benno

Yep, the link to the plug-in is provided in my previous post above

Astroman (Andrew Wall) · #14 14-06-2007, 09:38 PM

the spikes are a part of the package that Ken posted.

Several things you can try are to take some 30-45 second exposures with your 18-55mm lens. Firstly you need to get the focus to infinity. This is a little tricky to begin with but gets easier over time. Marking the lens is one way to remember where the infinity setting is. There are a few threads around that mention how to do this.

I personally take a picture, zoom in and look at the star image, if its out of focus, tweak the focus again and take another pic, then zoom in and eventually you will find the spot where the star is at its smallest diameter. Takes a while. Another way is to set the camera on AF and try and focus on a bright star, this is usually enough for widefield stuff.

Download a bit of software called Deepsky Stacker http://deepskystacker.free.fr/english/index.html

You can pretty much use this program out of the box, its free and just read the FAQ and manual to get an idea on how to stack your images.

Take several pics 10 or more about 30s or so ISO 400 or 800 in jpeg first then you can progress upto RAW later. JPEG just makes it quicker while your learning. Open the images up and register them, it usually stacks them automatically if you have it set. Then after it had done its thing you can save the image as a TIFF file and edit it that way. You will be amazed at the amount of detail you can get out of a 30s exposure stacked.

Dont hesitate to ask any more questions.

Benno (Ben) · #15 15-06-2007, 09:53 PM

thanks for more tips guys, most appreciated. once this weather clears up here in Newcastle i'll be able to get back out there and get a few pics and put up my efforts.
ballaratdragons: sorry dude, i forgot all about that link cheers
Benno