I wouldn't strongly recommend them for Astronomy either... as neither would I recommend the bigger 15x or 18x 50s Not because they're bad binos.... they're actually very nice, but they do exhibit a behaviour that excludes them from use in my view. They all suffer from a regular but tiny defocussing, or shimmy if you will. It's very slight, and most people don't seem to notice it at all, but I've seen it on my 15x & 18x50s (now sold) and most recently the newer design 10x42Ls when I tested them at IAS last weekend. I even managed to the get the Canon salesman to see it once I showed him the best way to check.... which is to look at something where a steady image outline is easy to monitor, such as reading words on a white sign in the distance. Just look at a single point and then the image will shift, or maybe go very slightly fuzzy every few seconds..... but only by a tiny amount. It's hard to explain, but once you've seen it, then you'll see it easily again. I couldn't cope with it whilst looking at the stars and moon.... and hence sold my two Canon IS already (about a year ago), and was thinking the 10x42L with improved optics would remedy this.... but alas not. I'd be interested to know if anyone else has noticed this? The Salesman said he'd heard of it before, but had always assumed people were talking about the more obvious full image shift as the optics compensate for movement.