retaining colours in the stars

[neil groves]

How do I do a long exposure on a nebulae for example and retain the colours in the stars in the field? I am getting some nice gas captures but my stars all appear white and burnt out?

Neil.

[RikM]

Careful stretching of the histogram so you don't clip the white point. If they are burnt out straight from the camera, drop the ISO or take a set of shorter subs just for star colour and layer them in.

[neil groves]

Sounds good, I'll definitely try these hopefully this weekend, thankyou.

Neil.

[Nathan_Pembs]

My stars turn out all white also, I've heard lowering the ISO will help as mentioned above.

Been using 800 lately, so will drop to 400 next time I'm out imaging

[sharkmelley]

Don't alter your ISO to prevent star saturation.    Choose your ISO to make the most of faint detail.  You can then do a few low ISO frames to add into the mix if necessary.  There is a myth out there that DSLR cameras destroy star colour because of saturation.  I rarely encounter this problem, even using 5 min exposures at f/2.8 at ISO 800.  I think the problem is applying a large dose of "Photoshop curves" to the image too quickly.  It pushes all bright objects to saturated white unless you are very careful.

Mark

[wxsatuser]

How do I do a long exposure on a nebulae for example and retain the colours in the stars in the field? I am getting some nice gas captures but my stars all appear white and burnt out?

Neil.

Have a read of this.

http://www.astropix.com/HTML/J_DIGIT/STARCOLR.HTM

[RikM]

Don't alter your ISO to prevent star saturation.    Choose your ISO to make the most of faint detail.  You can then do a few low ISO frames to add into the mix if necessary.  There is a myth out there that DSLR cameras destroy star colour because of saturation.  I rarely encounter this problem, even using 5 min exposures at f/2.8 at ISO 800.  I think the problem is applying a large dose of "Photoshop curves" to the image too quickly.  It pushes all bright objects to saturated white unless you are very careful.

Mark

Yes. I regularly shoot 7min at ISO1600 f/5 and have no problem retaining star colour. Careful processing is the key and turning offall the in camera preprocessing.

But a set of short subs just for star colour is quite easy to do.