Improving My Focus

I was hunting around looking for some way to improve the focus on my Pentax on Saturn, and I found this method of getting a sharp focus which is fiendishly clever--and I did not know about. You make what is called a Hartman Mask, which contains two holes the same size on opposite sides, and which goes over the front on your telescope. Aim it at a reasonably bright star, and out of focus, you will have two images of the star; in focus, and you have one. I'll make one and report back when next we get clear skies. Right now, we have a wind storm going on that is truly disturbing.