The "cross" in bright stars?

[caj1311]

Hi all
How do people get the "cross" (like the sparkle) in photos including bright stars - I am not sure how to even describe it to do a google search!
Thanks

[dimithri86]

Hey,

Google "Diffraction Spike".

Its caused by the vanes that hold the secondary mirror, or people adding it in post processing.

Dimithri.

[sheeny]

They are called diffraction spikes.

Typically they are an artifact of capture through a scope with a front spider - say a newtonian.

Some people like them and others don't. So there are ways to artificially make them in your images in PS:

http://www.iceinspace.com.au/63-430-0-0-1-0.html

Al.

[caj1311]

Awesome - thanks!

[RB]

Just to add to what's been said, if you have a refractor and want to create diffraction spikes in you images you can use fishing line across the scope objective (or over the dew shield).

I've used clear, medium thickness, line in a 'cross pattern' held in place by blu-tack or sticky tape, only need one cross.
You get a nice effect and no need to do anything in post production.

Like Al said, it's up to the individual, some like them others don't.

:)