I don't recommend ANY zoom binocular for serious work. Optical performance in terms of image quality, eye relief and field of view is ALWAYS significantly lower in a zoom binocular than in a comparable fixed power binocular and mechanical reliability of zoom binoculars is notoriously poor. In short, there is no such thing as a zoom with good optical quality and the very worst offenders are the zoom models that offer ultra high magnifications.
If you want a zoom optic, a much better option is a spotting scope on a tripod. In a binocular go with a fixed power model, such as the Pentax 20x60 mounted on a standard photo tripod. _________________ Thanks for posting with us
Joanie K - Your personal optics expert