From John in Montana:
I purchased three sets if Geovids for a long term bird research project. Estimating distance is the foundation of most songbird monitoring projects as it allows biologists to calculate accurate density estimates for various bird species encountered on surveys. Having binoculars, rangefinders, thermometers, clipboards and whatever else is simply too much for an observer to handle and still have there head up enough to make good, accurate observations. Geovids are one of the best binocs out there for optical quality and a first rate rangefinder and allow the observer to get exacting distances on each bird in view...at much longer distances than standard rangefinders, and allow the observer to be "looking" not fumbling with equipment. The cost of a good set of binoculars and a decent rangefinder used separately is simply not that big of a savings given the serious handicap it presents. I would seriously encourage any biologist considering their budget items for a bird study involving distance estimation to invest in these binoculars.