Which ISO setting...

[SkyExplorer]

Hi all,

Is there a recommended ISO setting when using a dslr for dso imaging?

Thanks

Steve

[brantuk]

Depends how bright the object is really - I've seen lots of nice shots between 800-1600 ISO

[dph1nm]

Changing ISO doesn't change the number of photons you detect, so for astrophotography it is not a particularly critical issue.

However, read-noise does vary somewhat with ISO, but this probably depends on your make of camera. For Canons, the lowest ISO are best avoided - optimal read-noise is probably around ISO800-1600.

With bright objects high ISO might saturate - depends on exposure time etc.

NigelM

[George]

ISO800 is regarded as the sweetspot for Canons, if you have light pollution the higher ISO's will saturate the image quicker. I'm in a heavily light polluted area and ISO800 for a maximum of 5 minutes is my limit regardless of target brightness.

[SkyExplorer]

Thanks for the replies, I've got a 450d, so ISO800 sounds like the best option.

I live just within the M25 so light pollution is moderate