Thanks for the advice, Andrew. That's exactly what I trialled recently, ie. shorter exposure and higher gain, and got excellent results. The number of subs I was losing dropped dramatically and I think I've found a goldilocks place for exposure vs gain from my Bortle 5 backyard.
Question: how do you collimate your SCT? Unfocused star? Tri-Bahtinov mask? Both? Something else? I'm using a tri-baht mask and now have all diffraction patterns/spikes centred at the focus point (after some tweaking of the secondary's three screws), I'm presuming that means it's collimated.
Quote:
Originally Posted by Millsy
Have a similar setup to you and found that a shorter exposure reduced the star size considerably. I got far more usable subs the second time around. Gain also played a hand. It's nice to see bright subs when taking them but when you get them to processing you really see the good from the bad..
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