Quote:
Originally Posted by gregbradley
If you use CCDStack you have no choice as you'll hit memory errors very quickly.
I'd say the max I can stack in one go in CCDstack with 64gb RAM is about 40 subs.
Perhaps this is another advantage to PI.
I have regularly stacked batches. I haven't done side by side so can't comment on that except that I get good results stacking stacks.
I also wondered about this as well. I agree with Rick. The statistically based combine methods would work better with larger numbers of subs to define more accurately the outliers for noise rejection and also for data rejection techniques.
But I am pretty sure the maths would flatten out fairly quickly so the the stats would be pretty solid once you had already stacked say 20 subs. Further subs would not add to much to the rejection process in my untested opinion. That is to say if your data was already noisy its going to make not enough difference to be too noticeable. If you had good data then you should get a nice solid clean final stacked image.
But when I upgraded my computer I did go for a lot of RAM so I could stack a lot more than I could before. With 6gb RAM I think I could typically only stack about 10 1x1 binned 32mb files.
CCDstack uses too much memory and is limited in this regards. Sequator does not seem to be so limited neither is PixInight (I just stacked 200 files that were about 40mb each in my LMC image).
I guess my point is I can't see this being the difference between a good image and a bad image but I know we strive for the best results with our data. I just can't see it being that important except on the faintest of objects.
Greg.
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Sounds like something not right there Greg as I regularly stack a couple hundred at a time in CCDStack mine are 32Mb each I have 32Gb Ram and I watch it get used up to about 80% but never fails to load them all . Win10 64bit