Warning: ASIAIR TestFlight v1.9 (firmware 9.21)

w7ay

@asiair@zwo

All:

If you are using Bin2 for guiding, do not download the ASIAIR Beta 1.9 (9.21).

The star detect algorithm in Bin 2 is screwed up. While I can detect 12 stars easily using 1x bin. With 2x bin, I can hardly get more than 3 stars. Ditto during calibration.

Plate Scale: 250mm /f4.54 and ASI290MM.

With Bin x1, my star sizes are between 2.5 and 3.5.

With Bin x2, my star sizes are between about 1.3 and 2.

I suspect ZWO did not scale their star detection threshold to compensate for the binning. I will be trying longer focal length guide scopes (275mm and 300mm) to see if the larger stars will allow more to be detected.

Chen

w7ay

As I suspected, switching to a second guide scope (Askar FMA230 without the reducer, ASI462 with IR cut), I am getting at least 7 stars now.

The Askar FMA230 without the reducer has a nominal focal length of 275mm (plate solve tells me 276mm, pretty darn close).

The star size with the f/5.5 guide scope is around 1.8 to 2.6.

I have a 300mm focal length objective (the just-released Borg 54mm acromat) that I have adapted for the Askar tube, but have not tried yet. Perhaps I can try that to see if the star size is even better with the larger f-number (albeit with poorer SNR), in case this bug remains there without being fixed in future releases.

Chen

w7ay

By the way, this is the photo I took earlier with the Askar guide scope and the Borg 55FL guide scope side by side, ready for testing to see if the longer focal length is better with Bin x 2. The Borg took the place of my imaging OTAs.

Well, the longer focal length is better for now, not because of any theoretical reasons, but just because ASIAIR Beta cannot detect the sharper stars from the Borg.

Chen