wispy lines???

[Daniel-K]

i have some wispy lines in my image and would like to know what they are?

thanks

Danny

[FraserClarke]

Looks like you haven't used flat fields? If you have some drift between the images, then the dust spots on the image get 'smeared out' when you align+combine on the stars, and you end up with these patchy streaks. You'll get a similar effect from not using darks, though then it tends to be lines of pixels rather than patches.

If you did use flats & darks, I'd guess there was something wrong with the flats... at least that has always been the culprit when I get this kind of effect.

[Daniel-K]

i did use darks but not managed to take any flats yet still just trying to figure out my set up and what works best but will try and start taking flats

[Dann]

I have pretty much the exact same thing on some of my photos when I stretch the histogram.

My initial thought was that it might be the fabric of the t-shirt I use to take flats. I have since tried with a few sheets of white card instead and haven't noticed it since (although I probably need to test it some more)

Does your image above include flats taken with t-shirt stretched across the scope?

[Dann]

ah you got that in before me

Maybe my problem isn't due to flats then

[ollypenrice]

The diagonal streaks running lower left to upper right? I think this is classic thermal noise so I'd wonder if the darks were taken at the same temperature as the lights? I wouldn't think flats have anything to do with this. (I say this because I've seen these diagonal streaks in my CCD results, occasionally, when the cooler has gone on the blink, usually without telling the on-screen temperature guage that it has done so!

Olly

[JimStan]

I have a friend who takes pictures with an inexpensive CCD camera, and he OFTEN has that artifact in his pictures! Thanks Olly ! ! ! I'll pass along the info.