Adjusting til on full refractor stack

There are many parts the contribute to the tilt we observe on the images. The most critical is the camera stack, everything between the camera and the focuser. There can also be misalignments and tilt in the refractor itself that contributes to tilt (e.g. the focuser). Based on the assumption that the front ring on the refractor is perfectly aligned with the optical axis, we believed that it should be possible to use the TiltAdjuster on a complete stack.

Tests show very promising results. Below are images of a setup used for removing tilt on a Askar FRA400 stack.

The images below show the tilt circle, and the 3 yellow circles before and after adjustment of the tilt.

Before After

When using the TiltAdjuster we must expect several red blobs. These are coming from different lenses and glasses. I therefor had to use the manual blob center option.

It required a couple of rounds with adjustment before the result is acceptable. The whole process takes less than 10 minutes. The difference on images is the proof of the pudding. Below is the CCD Inspector analysis of images taken before and after adjusting the tilt.

Total tilt 14%. Total tilt 6%

This is a quick an effective procedure that can be done inside before putting the telescope to work.

Please note the requirements with respect to the front ring being perfectly aligned with the optical axis. The adapter should ride on the rings that is used to fasten the primary lens.