Quote:
Originally Posted by lazjen
Yep, got it, get that ROI small to up the fps. Gain for the 1600 - what would be good - 200? Is it worth having the camera cooled since I have the option?
I'll try to get it working with the Baader FFC since it's probably the best glass I've got for the purpose, so it might be closer to 3x.
And I'll have to check the collimation first... It's been random clouds in recent nights, maybe it will give me a chance in the coming week.
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With the 1600, pretty much anything up to 300 is in the analogue range. It will depend on how much you need...aim for getting the histogram levels up to about 60%, by a combination of gain and exposure time. Cooling holds no advantage at such short exposure times. At high gain there's no advantage to bit depths beyond 8-bit either, as any lost precision is (re-)gained during stacking...and 8-bit can give you 2x the frame rate of 16-bit.
I usually let the ROI dictate the fps and dial up the gain accordingly, but the 462 is OSC and pretty sensitive, so that's a bit of a luxury. Some of my recent Martian experiences have been in excess of 300fps in an effort to try and capture some decent frames in the generally rough seeing...this past week down here has been pretty awful despite some promising forecasts
Regarding the Barlow...if you're starting out, I'd recommend being under rather than over as it's less tricky. The seeing will mess with you, and it's hard to separate bad seeing from poor focus and/or collimation. Remember you can get variable multiplication with practically any Barlow with a separable lens piece (one that threads off of a 1.25" barrel), and the optical quality only really matters in the centre since the planets are such tiny targets, in our apparent view. I hit roughly f/15 this way, which works well with 2.9 micron pixels.