What alot of people don't understand is a 50mm resolves more at far distances. In other words for varmit hunting, I highly suggest 50mm. At 500 yards, instead of a groundhog looking like a fuzzy blob, you can actually make it out. You might be able to actually id a deer antlers at 500 yards. A 50mm has 36% more area also, so lets in more than 3% light. I wonder if that 3% is linear or logrithmic.