Summary: For astronomy, these waterproof binoculars have clear stellar images all the way to the edge of the field. The field is a little smaller than the similar Nikon Action Extremes, but those don't have unblurred pinpoint star images at the field edges. I chose these for astronomy, being the most powerful binos I can hand-hold at 10x. The coatings seem excellent, and the weight is reasonable. They also have very nice, solid pull-out plastic eyecups instead of rubber.