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Cloud, cloud and more cloud – but looking on the positive side, this presents an opportunity for a ‘project’. Now, I’ve already done the observatory ‘spring clean’ – I even have the photos to prove it – so I thought I’d tackle a project that has been on the back burner for years; auto-focusing my camera lens(s) for wide-field imaging. Despite two attempts at putting the TS Telefokus 105 microfocuser on my Christmas list so that I could accurately focus my Canon 200L telephoto lens on the stars, there were no takers so the project stalled. However, having bought a second motor for my existing autofocus controller to install on a new telescope got me thinking that maybe this would actually be a better way of controlling focus and might even allow autofocus during a long imaging session to compensate for temperature changes. So, I put a third motor on my birthday list and my two sons clubbed together to buy it for me moving the project forwards! Yesterday, I completed it with the addition of a finder-guider that I had in my ‘goodies’ box that is normally used for guiding short focal length review telescopes. Now, in fairness, it is untested on the night sky (cloud, remember, hence the project!) but what I can tell you is that the focuser moves in invisible increments or quickly as required, is ultra smooth and shows no sign of slipping! Unfortunately, much as I’d love to, I can’t install my mono camera as, with its built in filter wheel and OAG, there is insufficient back-focus. This means that the system will be used with my OSC SXVF-M25C coupled to the Canon 200 L lens using a custom adaptor I had made when Adam was a lad. What could possibly go wrong? Front View The two pictures above show the 72mm lens has been stooped down to 52mm using a step-down ring. This reduces the aperture from f2.8 to f3.8 to improve star shapes at the periphery of the FOV but without adding the diffraction spikes that would be a feature of stopping the lens down using the iris. Belt Drive Finder-Guider Connection