A new gadget - the camera rotator

One of the issues I’ve been having with the astro-cam has been framing - getting my intended target the ‘right way up’ in the camera. I’ve also been troubled by having the camera rotated at different angles (relative to the long axis of the telescope). This comes about because all the components are threaded together, and different components have different lengths of thread available.

So taking the filter holder out and installing the 21mm spacer leaves the camera at a different rotation. As you can imagine, stacking and processing data taken over a couple of sessions can be difficult if I’ve changed the components in the optical train.

Which is where this handy little gadget comes in.

What does it do?

It goes between my telescope and the filter drawer (which I will be leaving in the optical train on a permanent basis - I finally got it rotated to (almost) the correct position relative to the camera!) so that I can rotate the camera a full 360 degrees (cables allowing) to perfectly frame my targets. Once I get a shim that’s the correct thickness I’ll have everything lined up perfectly.

Of course, I do now have the task of re-finding the base point to begin auto-focusing, as I have changed the position of the camera relative to the telescope’s objective lens.

There’s also the question of whether I want to add a spacer in there so that the focuser is not extended quite so far. This would have the effect of (theoretically) reducing ‘droop’ as the focuser is extended further. (Most of the shops are sold out of the small extension tubes, leaving me with the option of using 16 or 21mm tubes. Which will make a massive difference to the focuser initial position…)

Looks like I’ll need to get another photo of the assembled rig at this rate…

• Astro