Have I wasted 70 minutes?

[batema]

Hi, I have just taken 70 minutes worth of darks at ISO 1600 but will shoot my images of Centaurus A at ISO 800. Is it possible to stack 1600 darks with 800 lights?

Mark

[batema]

Sorry didn't think the other thread went through.

Mark

[KenGee]

Answer is no save the darks for next time, take the temp and save info in the folder on the pc. As you start to build a data set the time you need to spend taking darks will reduce. but you will need to take new darks for ISO 800 sorry. but save them as well.

[TrevorW]

Sorry no in fact don't save the darks for next time, as I've learned darks can differ from each session depending on such things as the ambient temperature and the random nature of hot pixel generation.

[peter_4059]

Mark,

I'm no DSLR expert but in the case of the DSI II it saves all the sets of stacked darks in a library with the exposure time and temperature. In subsequent imaging sessions it searches through the library and finds a dark with the time and temperature within a set tolerance. If it can't find a match it tells you to take a new dark. I can't see any reason why this wouldn't work for the DSLR - I assume you would need to match up ambient temp, ISO setting and exposure duration. Darks won't remove random noise no matter when you take them.

Peter