bit of help needed with beginners widefield shots !

[cal1985]

Hi all, im a bit puzzled! how can i get the star spikes that i see on other peoples images? do i need alot more data or longer exposures? or our these artifically put in when processing ?

i was origionally using GIMP however i have just purcashed photoshop, any help or comments would be grately appreciated.

cal

[Steve 1962]

Hi Cal

The spikes appear because of light diffraction around the supports for your scope's secondary mirror. You've probably got four supports at 90 degrees to each other, so with longer exposure you'll see four spikes appear aroudn brighter stars.

Some people like them, and others don't - because they are a scope produced artifact rather than a natural stellar phenomenon.

If you really like them there are several programs that will add them for you such as Noel Carboni's actions and Starspikes Pro - personnally I'd save my money because I prefer images without them.

Steve

[cal1985]

processed with GIMP

35-70mm lens used at 35mm 3.5apruture.

cygnes. 26 lights at iso800 2mins

10 lights at iso 1600 30sec

darks were 13 iso 800 2mins

5 iso 1600 30sec

[cal1985]

thank you for that, i always thought that it was the stars producing that effect ! lol still have so much to learn.. another question i have is the effect that flats have on images. what does this do? and how do i take a flat?

[cal1985]

aquila zeta. processed with photoshop.

16 lights at iso400 5min

5 lights at

iso 800 5mins

equal darks

[Steve 1962]

Hi again Cal

Great shots - well done.

See here for various ways of taking flats..

http://stargazerslounge.com/imaging-tips-tricks-techniques/140012-method-taking-flats.html

[cal1985]

steve that has helped so much thank you for that. i think the t-shirt is going to be the easiest way. again thank you

[Steve 1962]

That's a pleasure - it's great to see you making such a cracking start

Regards

Steve