M13 last night

[russ]

Hi all,

We had a cracking night last night. Wasn't going to bother because of the moon but it was just too good to be true.

First thought was just some star trails because it's easy to setup. But things got out of hand and it wasn't long before I had dragged the entire kit out.

I seem to have a thing for globular clusters right now and couldn't resist another go at M13, especially as my first attempt with the Newtonian was below par.

So here we go. Three images, all the same but with different levels of processing. One is purposely over processed to bring out the galaxy that shadows M13.

I don't suppose someone like Andy could try an even illumination across the image? Be most grateful.

The image consists of 25 x 45 sec images at 800iso, taken with the 300D, Explorer 200 and EQ6.

Regards

Russ

[OXO]

Lovely set of images Russ i like image 2 best of all, you can make 2 galaxys out i think on your 3rd image?..

James

[Astroman]

Lovely set of images Russ i like image 2 best of all, you can make 2 galaxys out i think on your 3rd image?..

James

Where? I only see Ngc 6207 as usual. Off the lower right of the image is Ngc 6196, but I don't see it.

[OXO]

Having look again and processed the image it's just an artifact from the camera :oops:

[AndyMac]

Hi all,

I don't suppose someone like Andy could try an even illumination across the image? Be most grateful.

Regards

Russ

'Fraid removing vignetting, even after following Jerry Lodriguss's website at http://www.astropix.com/HTML/J_DIGIT/VIGNET.HTM is something I've never mastered Russ. Sorry.

Anything involving layers & I'm hopeless.

My personal favourite is the first one. Plenty of detail & a fine smooth, even background.

[OXO]

Thats a good link you posted there Andy and one i will find most usefull in the future i feel a learning session coming on with photoshop.

James

[Rob]

nice going Russ... like the first image

[Rob]

nice going Russ... like the first image

[AndyMac]

Good luck James. I tried following this link a few years ago on several of my f6.3 focal ratio piccies (terrible vignetting!) and got absolutely nowhere!

Some people are left-handed, others are right. I guess I'm just plain 'ole cack-handed when it comes to processing.........

[OXO]

If i get to grips with it i will write an easier version of it Andy could be my first Info page on the new website of mine

Processing wise i have been used to doing planet's now i am getting deep sky images it's a whole new ball game :shock:

James

[Ant]

Vignetting removal is really easy once you know how.

Get the image into Photoshop, duplicate the image so you hve the background layer and Layer 1.

Select layer 1, and do a gaussian blur so that all the detail is gone but leaves the background.

Then in the windows - Layers dialog box select difference - this then removes the blurred image from the normal image leaving a nicer image.

I've done this to Russ's imaged and mailed it to him - if he likes it I'm sure he'll post it!

Ant

[OXO]

Nice one Ant just been playing in photoshop, i would add that if you find details are lost try lowering the Opacity to retain some details.

James

[Ant]

Yeah I know that I missed that off... Also worth mentioning that the bigger the object imaged the harder it is to do this without loosing some detail.

I.e. M57 images are great because M57 (being small and conpact) doesn't add much information to the Guassian Blur - whereas M31 M13 which are big objects can affect the background brigtness using this method (to remove it).

Also with Russ's image I had to lower the hue and saturation on the red channel for some reason. I think this is because I was working on a JPG file (and some compression artifacts started to show through when I tried to pull some of the lost detail back). It works a lot better with a full size TIF. But at 36meg they don't email well...

All in all a great image - I do love M13! and Russ has done it justice.

Ant

[OXO]

Its a great Tip Ant given any more thought's to a little processing tutorial regarding Star Trail's? you did such a good job with my images the other week.

I agree this M13 is excellent.

James

[russ]

I got the image from Ant......really nice job. Worked wonders!!!!

I've actually done that procedure myself but forgot how to do it. Thanks again Ant.

Although one thing i do need to do is find out why i'm losing the red/orange colour to the stars in the cluster. The individual raw images show the brighter stars in the cluster to have a fantastic red colour, as they should be. But after stacking that goes.

Also, may try you technique on the second image Ant as it's not so overprocessed.

Russ

[Ant]

The problem with the method used to remove the vignetting is that it removes a lot of the colour as well...

When you trythat methog on the second image, move the opacity bar down to about 75%. that may help with the star colour.

Ant