Scale for focussing tube

Hi, it’s useful to know the focussing position especially when imaging and using different combinations of filters/ lenses with the camera, although my sky watcher 120 Evostar has a graduated Crayford focuser, the newly acquired ST102 doesn’t, so rather than replace the rack & pinion focuser with a calibrated Crayford I managed to source some transparent adhesive scale tape, which I have attached to barrel, after cleaning the area with some isopropyl alcohol, its still on but have yet to put it to use. The tape was relatively cheap, and I do have an excess of repeating 40cm lengths, so if any one fancies adding a scale to their focussing tube get in contact.


Pete Hill