Help- Green star trails

[long_arms]

Hello,

The other night I thought I would just get 30 minutes of star trails with 30 second subs. Just a little test, nothing special (I've never tried it before)

Using 350d and 18-55 kit lens stopped down a couple of notches at least.

I ran the Cr2 files through Pipp then startrails.de and I also stacked and blended them with photoshop to see if it would be better.

The fainter stars are green, why is this? Would longer exposures help? Is it my settings? Also the stars are stripey.

This is the startrails.de stack without any processing whatsoever.

Thanks

Dan

Edit: Forgot to say I have edited it to look nicer and even done horrendous things to the levels etc to make the green stars less obvious but I want to know why they're green and stripey to start with. Thanks

[long_arms]

I've sorted this, well in a way.

I've realised that the Raw files were fine and it was PIPP which was turning the stars green. Not sure why, I left the debayer settings on the default and played around with them abit as well.

I'm not having a go at PIPP its a great piece of software that I'm clearly not using correctly

I created an action to make star trails from the Raw files in photoshop and no green stars. Some nice colours even! (I know I could have converted to Tiff using PS and used startrails.de but thought I'd just figure it out on PS)

Dan

[cgarry]

Hi Dan,

I think you were using PIPP outside of its comfort zone there! By default PIPP does not any colour space conversion, instead it just outputs the raw colours from the camera sensor. You can change this with this control:

* Input Options->Output Colour Space

Setting it to 'sRGB D65' should give a more human friendly colour tone.

Though I think your photoshop solution is the best one.

Cheers,

Chris