Print Page - Treatment for lens flare

Title: Treatment for lens flare
Post by: MarkS on Oct 22, 2011, 00:20:20

Let me know what you think of the following processing for removing flare around bright stars (which particularly plagues the Bananascope with its chunky spider). So far, I've only treated the central star and l've deliberately left some residual flare so it still looks natural.

http://www.markshelley.co.uk/webdisk/lens_flare_before.jpg
http://www.markshelley.co.uk/webdisk/lens_flare_after.jpg

Without going into ghastly detail, I've masked out the bright stars so I can calculate a "circular average" of the background around the bright star and then subtracted that average.

Mark

Title: Re: Treatment for lens flare
Post by: Mac on Oct 22, 2011, 03:54:50

Looks pretty impressive to me.

It would be interesting to see this on a full sized image,

Mac.

Title: Re: Treatment for lens flare
Post by: RobertM on Oct 22, 2011, 08:36:48

Yes that looks like a promising technique especially if it's a whole image process.

Robert

Title: Re: Treatment for lens flare
Post by: JohnP on Oct 22, 2011, 17:05:26

Well it's definitely worked. The only thing I would say is that by removing the outer glow - the inner glow (the one that is about 1cm in diam) is a lot more prominent... can you lessen this one also?

John

Title: Re: Treatment for lens flare
Post by: MarkS on Oct 22, 2011, 18:10:43

Quote from: JohnP
Well it's definitely worked. The only thing I would say is that by removing the outer glow - the inner glow (the one that is about 1cm in diam) is a lot more prominent... can you lessen this one also?

Possibly, but I'm still experimenting. Also I'd like to apply it semi-automatically to all stars - at present I would have to laboriously do it one star at a time. Also I'm not sure I can justify the technique scientifically - I'm tampering with the image in a manner I'm not entirely happy about :(

It's the start of a slippery slope - I may end up removing diffraction spikes next :evil:

Mark

Title: Re: Treatment for lens flare
Post by: JohnP on Oct 22, 2011, 18:14:33

QuoteI may end up removing diffraction spikes next

.... or adding more.....!!! ummmm diffractions spikes........

Title: Re: Treatment for lens flare
Post by: Tony G on Oct 22, 2011, 18:49:04

Quote from: MarkS on Oct 22, 2011, 18:10:43

at present I would have to laboriously do it one star at a time.
[/quote]

:o

Well that will keep you busy..........................for a few millenniums ;)

Tony G

Title: Re: Treatment for lens flare
Post by: Mac on Oct 22, 2011, 19:16:07

Quote... or adding more.....!!! ummmm diffractions spikes........

Noooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo :o

sorry thought we were going to go down that old slippery slope again.

panic over.

Title: Re: Treatment for lens flare
Post by: JohnP on Oct 22, 2011, 20:58:43

:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:

Orpington Astronomical Society

Astronomy => Technical => Topic started by: MarkS on Oct 22, 2011, 00:20:20