more colour/levels help?

[chemtom24]

ifve been using gimp for the first time trying to process my first couple of images. ive been following this as a basic guide

Astronomy Shed UK Astronomy Forum • View topic - Superb Processing Tutorial

but i wonder if anyone can help me get rid of the bright white area in the bottom right of my pic? not sure what to do or how to do it.

thanks, tom.

1st pic is straight from dss with levels adjusted. 2nd is from gimp after a little more playing around.

[ollypenrice]

Looks like unwanted light so is it LP, a light leak or an accidental illumination near the setup?

In general flats take these out but this looks very concentrated in one corner so I'd have thought it wiould be a source visible at the site. Street lighting etc.

When you take darks does the same corner show a glow?

Olly

[chemtom24]

it would indeed be light pollution. not a nearby streetlamp but an illuminated building on campus. i was quite far away from it but its still affected the image. guess il have to go to a darker site next time.

darks... i havent even added any darks. shoudl i? i thought they were only for hot pixels. and flats.. no idea sorry!

i do have not an incling of what im doing here

[roundycat]

some info on basic image calibration here; Astrophotography

Dennis

[Demonperformer]

Tom

Every time you take a photo and save it, it creates noise. Darks help eliminate it.

Flats help remove imperfections in the optical train (e.g. dust bunnies & vignetting). You need an even light source for them, but this can by synthesized by stretching a white T shirt over the end of the scope. The most important thing is not to alter anything (e.g. focus) in the optical train.

HTH

[dph1nm]

There are some GIMP astronomy plugins here

Gimp Plug-Ins - Programme - Georgs Homepage

one of which fits a background gradient.

NigelM

[chemtom24]

tanks nigel. i downloaded and installed ( i think) the latest link. trouble is, i have no idea when it comes to using imaging programs.

[Demonperformer]

Do you have a copy of First Light Optics - Making Every Photon Count - Steve Richards Contains a ton of information on playing with the levels and curves. And it doesn't presume any prior knowledge, so great for someone with 'no idea'. Worth every penny.

HTH

[chemtom24]

ah dp i do, brought solely on the recommendation of what seems liek every other member here! - it came the other day but ive sidelined it cos i also got some pop science books and i wasnt really going to start imaging until i get home in a couple of weeks.

maybe i should get reading..

[Demonperformer]

Well, it will certainly help with the basics. But as long as you still have all your files, you can redo the processing later, whenever you get round to reading it.

[Jannis]

my result after 30 sec in photoshop (as i'm falling asleep here, and want to go to bed, lol):

what i did was simple:

open pic -> add new duplicate layer -> on new layer, add gaussian blur untill all stars have wanished -> on blured layer, select difference -> set layer to ~90% in this case (different from pic to pic), so pic looks more or less even luminated.

Now, this can be doen at least 20x better, but shows how easy you can do it in PS to get an ok pic in a few sec, or a quite good pic in 10-30 min if ti's a lot of details in the pic.

not sure if this helped you anything, but...

[chemtom24]

thankyou jannis this helps alot because I can now try and follow your method in gimp

[Cloudwatcher]

Whilst tinkering with your image in CS3 it looked as though I should be looking at part of the Milky Way so I pushed the background as far as possible without going too 'blobby'............. came up with this.

Please tell me I have not made a complete *** of myself.

[chemtom24]

no no i love it i am so amazed at how much detail was captured and what can be brought of an image! ##i have no idea how to use image processing software so its all mystical to me, and i love seeing peoples attemts at processing an image

thanks very much