I decided to buy an Alnitak Flatman XL instead of modding my old flat box (I sold my Canon 60Da so had the funds).
My final target of the night consisted of a sky target light frame event, then several flat frame events (one per filter), followed by a flat dark frame event (all the flat lights were 3 seconds), and finally by an event containing regular darks for my target object.
The problem is that SGP did not turn off the panel after the flat light frames. The panel being on could easily contaminate the darks, especially since some were 30 minute darks for narrowband. It also runs the panel for hours instead of minutes.
Just a note: The Optec SW was not running or connected.
Log is at:
Note the log file is still full of errors caused by the TheSky controlled Paramount ME discussed before on another thread. I would guess the panel problem was not related to this but maybe it is.
UPDATE: I tried it again the following night with no darks after the flats and it did turn off the panel but not until the end of sequence shutdown.
So (and correct me if this is wrong) it appears that this failure to turn off the panel is intentional with flats being “intended” to be taken at the end of a sequence. This seems a less than ideal way to do things, however, as it forces one to do the flats last which may not be optimal for the user’s setup, mostly due to morning light which might contaminate the flats (depending on how light-proof the user’s observatory or outdoor setup is).
If I was to suggest a change (and I am), I would say that before each event begins, the flat panel (where one exists) should be commanded on for flats and off for everything else. One could then take flats at any time without the panel remaining on when it shouldn’t.
On a more minor note, the first event flats were not consistent, varying in counts between 11,000 counts and 28,000 counts (same filter). This was only on the first (Luminance) set of 20 flats - it appears the brightness gradually ramped up for the first 11 frames ( 3 second exposures). By the 12th frame it had achieved brightness and thereafter for that event as well as for the other filter events, the frames were very consistent. It appears that some sort of “warm-up” was happening for the first minute or so. Has anyone else seen this with Alnitak panels?
This could best be fixed by a user set delay between the panel on and the exposure start. I know that one can insert delays in SGP but as far as I know this would also delay the panel being turned on the way the delays currently work. Is that correct?
In the meantime I can just insert a dummy set of flats event for warm-up (I did that on the second night and it worked) but it would be nice to be able to deal with this properly by inputting a delay in setup as described above.
Of course the panel brightness is probably not super critical because with flats the 20 frames will be made into a master and normalized so as long as you are in the linear brightness range it will probably be OK. Having said that it would also still be best to be more consistent in levels.
Of the two issues, the panel off issue is way more important operationally but I figured I would discuss both panel issues in the same post.