When to use 1600 iso

[Taff]

Hi' With 1600 iso speed when is it best used for captures of the night sky Thanks.Mark

[brianb]

It's the same sensor whatever ISO you set, if you're using e.g. AIP to process raw (.CR2) images then it really doesn't matter what you set the ISO at, you get the same results after contrast stretching.

It does make a difference with DSS, if you reduce the ISO there are less stars it will detect. Even so I have a feeling that the best thing to do is to set the ISO to 200 & leave it alone.

[dark knight]

As far as I know ISO 800 is the max most people tend to use as the higher ISO tends to introduce more noise than signal.,at least that's how I understood it.

[blinky]

I used to use ISO 1600 but now use 800. TBH I never really saw much difference between them both.

[Psychobilly]

ISO noise performance can vary dramatically between different models of cameras...

Billy...

[dark knight]

Very true Peter..I had a go using ISO 1600 with my D80 hoping it would reduce required exposure times and the results were abysmal, the subs were totally unusable.

[Catanonia]

I tend to use iso 1600 only to frame images before switching to 800 for the main sequence of subs

[Dave Smith]

I'm with Catanonia, I use iso 1600 or even 3200 to see that I have the object in frame and then reduce to a lower iso. I have only once stuck to 3200 and that was for M51 which otherwise hardly showed up in the images.

Dave

[johnh]

With DSLR's the ISO alters the 'well depth' with high ISO well fills quickly with low ISO well fills slowly with more electrons so greater well depth gives better dynamic range which is what you want with nebula and fainter fluffy stuff. DSLR's perform differently as said hence ISO1600 is unusable for some and 800 seems optimum. ISO1600 is better for star clusters as range is not so important.

John.

[Taff]

Hi' Thanks every one for your reply and help.Mark