My star pictures are improving and I am at the next stage of needing some money. My tracking seems to be limiting my exposure times to only a couple of minutes and there is a hint of star trails. So I need to do some auto guiding. I have been doing some homework. In the systems I have seen advertised, this involves a camera that is looking at a chosen Guide Star and there is a servo system to keep the guide and main scopes pointing at that star. Bearing in mind the powerful imaging processing that is available, I am surprised that a system is not for sale using detection of movement of the whole sky. Signal to noise ratio would be vastly better and pointing accuracy would go up accordingly. Are the present guiding systems good enough not to need improvement? FFTs of the present and previous images would show the spatial phase change in 2D and that would give the necessary correction signal. I would not be surprised if chips were already available to do this. Perhaps it's just a matter of cost.