M13 Shot

Greetings All, here is my 1st attempt at Globular Cluster M13 using my Canon Powershot A75 digital camera, 15second exposure at f3.5. I took this shot through my C8 at x50 magnification. I processed it slightly in registax and photoshop. I just know the basics so - please tell mehow to process it better :lol:
Keith...

Hi Keith,

First, can i say I'm very impressed with that image. Superb!
Secondly, I'm only starting to learn the basics of Photoshop so I'm not sure if i'm the best person to offer advice.
However, from what very little experience I have, this is what i would :

First, take more than one image - try to take as many as you can. Remember my image of M57 - that was only 18 images stacked together. Larry Lary reckons I should try and take about 100 or so of which about 40-50 would be useful !! The more images you have, the better as the signal/noise ratio improves with every image you stack/merge together.

Secondly, there's a bit of noise in the image (the small random speckles acros the entire image). This can be removed fairly easily from what I understand. Simply put the cap on the scope and take a shot of basically nothing for the same duration as the original. More noise is generated on warm nights than on cold nights so it's important to take this image onnthe same night as the original exposure. In Photoshop you can simply subtract the noisy image from the real image to come up with a noisefree resultant image. Some people even take several images of just noise, merge them so as to end up a better image with noise averaged across it and then subtract it as above.

However, that's not to take away from what is a superb image. Well done!

Clear skies,

Michael

Thanks Michael, i've heard of stacking using registax, this is what i done, I took about 12 images and aligned and stacked them but the stars seemed double, maybe the camera moved slightly during exposures - i'll have to be even more careful.

Taking 'darkframes' - I done this also, but registax would not allow me to stack a darkframe and my M13 shot on top of it to reduce the noise - guess i'll have to find out a bit more. I'm still learning photoshop, adding and subtracting images, so there's a long way to go

Thanks for your support Michael, Keith

Hi Keith,
Nice picture, its amazing how digital cameras and webcams have progressed astrophotography in such a dramatic way, 10 years a go a pic like that would have been a very difficult thing to get, and would have required seriously expensive cameras.
I've just dabbled in deepsky work also, but have nothing as good as that.
Keep up the good work.