I think at 50x you will not be able to come to any conclusions about your stylus, unless it is just plain broken. I have a digital microscope, cheap one, which goes up to 800x, and I use it for SRA. As far as determining wear, even at 800x, it is very hard to say conclusively that you do, or do not have wear. The best angle for wear determination is straight on, but even then, you have to know how much of the stylus is actually in the groove, and then what wear actually looks like at that magnification. I believe we are talking a out very subtle differences in the image, even at 800x. I don't think you stand a chance at 50x.