Oddity with Sky Flats

[Mark de Regt]

Hi,

After many years of sky flats generally working fine, an odd thing has cropped up, preventing it from completing the dusk flats I want it to take (dawn flats seem to work fine).

Specifically, I have it take, first (dusk flats), a narrow-band set, then a set of red OR green, and finally a set of blue or luminance; three sets altogether. There typically is time to do that (four of each, except I'll limit that to three of one of the broad-band filters).

But, sometime in the last couple of months, it has started telling me that it's too dark for the last set. This, just seconds after taking the last of the red or green, typically at less than two seconds duration.

Tonight, I watched carefully. As you can see from the attached "AutoFlat-20241219-Dusk.log" file, it went from very bright to very dark in a matter of seconds. I killed the run, told it to take only the luminance flats it had refused to take seconds before, and it was happy to take them. That's in "AutoFlat-20241219-Dusk-2.log," also attached. The sky was completely clear throughout.

Very odd, to say the least!

Also, as a separate issue, whenever it starts to take flats, it says, "**Overlapped slew/download disabled, cadence will be slower." If this means I can take fewer flats, and if this can be changed to allow "faster cadence," I would like to be able to do that.

Thanks.

mark