I did a final? alignment and check last night of the ITS.
This time I did 60s exposures and jogged the mount by 30' seven times about seven seconds apart.
This gives a line of diffraction patterns of the same bright star that are far easier to compare.
Horizontal image 2MB
http://d1355990.i49.quadrahosting.co...2_10/A_hor.jpg
Vertical image 2MB
http://d1355990.i49.quadrahosting.co..._10/A_vert.jpg
Horizontal alignment is almost perfect ie within about 5 micron. This is less than a 9 micron pixel! In angular terms about an arc second misalignment horizontally.
Vertical needs to come up a tiny tad. The sensor is about 15 micron closer at the bottom compared to the top.
The last image is a single 8minute exposure in 3nm HA of a bit of the Vela SNR.
Full size image here 10MB
http://d1355990.i49.quadrahosting.co..._10/VelaHA.jpg
Bert