20180711 Jupiter as a test of the DIY electric focuser

Made a quick and dirty first version:

Still need to find better way to mount the motor so that it could be fixed along the OTA direction.

Anyway, it works.

We got 0.1/10 transparency, the Jupiter was a fuzzy patch of light with naked eyes.  I've to push the gain to maximum, and shutter to something like 0.3-0.5 second to get a very dim image. 

Manual focusing is impossible under this situation and it also proves that the electric focuser indeed worked.

1409 (UT), and I got only 200 frames due to the long exposure required for each exposure, and thus a very low frame rate.  Anyway, it is just to test the focuser.