[Dave Smith]

I now always shoot in RAW for astrophotos or situations where post processing is likely to be severe. I was under the impression that when shooting in RAW you were saving the output of the sensor without the camera doing any processing. I therefore assumed that the ISO setting on the camera would have no effect.

However, if I do change the iso setting, the camera does make changes to the aperture or exposure time depending on which mode I am in.

So what is happening in RAW mode?

If I use manual mode and take two raw images with diferent iso settings will there be any difference?

I would be very grateful for clarification on this.

Dave