Skyflat behavior


#1

I tried the latest SkyFlat feature yesterday and it waited and went to the proper sky position which is very nice. But no matter what setting I chose (Dont Care/Stop Tracking/Dither) it would move the scope after every flat. Is there a way to use the sky flat feature without the constant slewing?


#2
  • Dont care is for all type of flat simple dont manage stop or tracking
  • Stop Tracking just stop tracking during flat exposure
  • Dither add dithering during SkyFlat slew between each exposure

Mount in SkyFlat must follow the best point or you find a Gradient on flat.
For this reason Voyager update position at each exposure of flat … it quick because we talk about some arcsec.

All the best
LO


#3

Would it be possible to have a threshold for the moves so maybe it will update the position less frequently? Between the slower readout speed of Voyager compared to using Maxim DL alone plus the time for the slews and settling it is taking over 10 seconds per flat exposure now. To get a complete set of LRGB flats (25 per filter) will take 1000 seconds now and there is not that much time during dusk to capture this many flats.

If for example the position updated at the end of each filter flat sequence it would reduce the time spent moving the scope considerably.

If that is not the intended purpose of this feature I have a DragScript for taking sky flats without moving the scope I can continue using.


#4

Again with this slow problem Mike ! SkyFlat is a bad way to do flat … also if i add a way to combine disaster i go fight with Voyager Phylosophy. I dont put a function if i dont think is a right way.

Anyway i add a red not reccomended options to say “no slew between exposure just between filter”.

All the best
LO


#5

I have a script to do things the way I want already so don’t feel like you need to change the way it works if it is the way you want it to be.

The rationale for trying to improve the throughput is the fact that for a good flat set my understanding is you want at least 100k e- in the total integration and this is on the low side. So with these CMOS cameras with small well depths you can only get 2-3k e- per exposure so you need 20+ exposures per filter. So it turns out you need lots of exposures so any overhead per exposure adds up.

I could see on a CCD camera with a very deep well you could get away with just a few flats and then this isn’t an issue but that isn’t the only use case these days.