Hi Chrys,
A quick shout out to say the 1600mm sensor is working well and seems to be a good match for my focal lengths which are around your 514. I go from 1.7"/px to about 0.8"/px with it and have much higher success rate (surprise!) at the 1.7 end, which is where you would be with that set up. With the 294 things will be even more forgiving as it has bigger pixels, but will have the trade offs in resolution associated with that.
I have not used flats or biases with mine at all, but always use darks. I can see myself using flats at least soon, though, as I try more RGB imaging.
Do you already have filters? if so and they are 1.25", the 1600 will be ok with them, but perhaps the 294 will suffer mildly? Its a tiny bit (5% on the diagonal) bigger. The ZWO 294 page has a nice comparo table at the bottom. The 294 looks a fairly significant improvement in just about every way. I'd love one!
https://astronomy-imaging-camera.com...t/asi294mm-pro
Sorry if that's all stuff you already know
