Last night was the first opportunity in some days to do some more work on the mount.

Previously I had raised the mount adapter by 2cm and also… forgot to lock down the roll-off building on one of those really windy nights this past week.

The building moved.. slammed into the scope, and moved stuff.

So… removed the camera, remove the barlow, remove the diagonal, insert the svbony 0.5x focal reducing lens filter adapter and put the camera back in.

Ran it over to Sirius to focus. OK. Park and shut down in the home position (should be 0 deg 0hr) start up, run sharpcap Pro Tools; polar alignment;

Polaris is in the FOV but too bright and the focal reducer is so bad the star is spread out and wiping out any chance of other stars being identified and plate solved. I ran the gain and exposure through many combinations but nothing! So sez my brain… if not the main scope how about the finder? It was aligned with the main scope earlier!

So.. that is what I did. Sharpcap and the 8×50 finder with the ASI120 camera did in fact work, plate solve and everything. I rotated the mount 90 deg in RA and sharpcap told me how very very bad the polar alignment was. Seeing the numbers on the screen I moved the mount up and down and left and right, waiting 3-6 seconds for the next image to update, and got it down to what I think was pretty excellent alignment… for a finderscope 🙂

Total Error 1 minute 26 sec

Then very carefully and very slowly were the RA and Dec nuts tightened… and the error reading did not change.

So my understanding of stuff is that the 3 star alignment dictates how good the pointing is and the polar alignment dictates how good the tracking is.

My last run I noted the tracking was very bad (I think after the building hit the mount in the wind). Last night however the tracking was … very good!

In 180 seconds I did not have to adjust the tracking at all and at the end it was still very close to where it started!

I did not have a chance to do a 3 star align after the fiddling around.. that is next time.

So.. back to Jupiter… seeing was poot, transparency was poor. Not a lot of detail or contrast at all. exposure time was higher than normal at 4ms. That tells me that I am looking through more air as Jupiter continues to drop and possibly through worse quality air as well. Airmass of 2.05 !!!

Oh! I did insert the IR cut filter for Jupiter… I have not yet determined if that changes the exposure by how much yet… another test for the future!

Best 10% of 20K frames, altitude only 29 degrees.

NEXT TIME on Survivor! Err.. Serenity Imaging!

3 star align!

pointing test!

tracking test!

exposure with and without the IR cut filter test!

oh look… Jupiter is gone for the season! 🙂