400 or 800 iso in primefocus

[Taff]

What is the best iso speed for taken captures at primefocus 400 or 800 i'm not sure for the best result Thanks.Mark

[jgs001]

Mark, I think it depends a lot on the camera, and how good your tracking is. I have been using ISO1600 with my 450d to try and capture as much detail as possible within the limits of my NexStar mount (Not tried with the HEQ5 as yet). The result did require more processing for dealing with the noise however. I think the ideal is as low as you can get away with to capture your target.

[Psychobilly]

As John has already said , it really depends on the target , the tracking and the camera... as your trying to get the best compromise ... your trading off exposure time - needs to be kept short if you have poor alignment and or tracking to avoid trailing etc in which case you'll noramally up the ISO to capture "more" in less time.. if the tracking is good then you can use longer exposures and then have a choice of low iso for lower noise and better colour or higher iso for more "detail" in less time...

Billy...

[Taff]

Thanks for the help and information on the subject.Taff