Thanks for the feedback chaps, much appreciated
These images were taken with the lens cap on sitting on the desk today at around 20C ambient temperature. I took 3 shots alike, and the ones above are the middle out of the 3.
I typically take 10-20 darks, and about the same number of bias frames. The number of lights varies by target, but I think the last bunch I've had about 15 minutes worth of data. I appreciate this isn't much exposure time, but I was curious about the exposure settings before taking extended sets of data. After all, I'm still working on my polar alignment
I will get a guider...eventually...I'm just trying to keep it simple for the moment to see how far I can get without needing to run the laptop and the additional power draw that requires. It's a good challenge!
So it sounds like I'm going to need to experiment with some sequences to determine what my best ISO is for the signal to noise ratio...thanks for the links Richard, very interesting reading.
Another question...is it possible that the "optimal" ISO is different depending on the subject? For example, one setting for fainter objects (galaxies for example) and then a different ISO for brighter objects like Omega Centauri, Eta Carina nebula and a select few other bright objects?