The Key XM30 model has a picture in picture 2.5-10x digital zoom and 2x optical magnification. With this model, a maximum observation distance for an animal, such as a deer is 1200 m. The field of view is 10.3 m/100 m which means that this model is more appropriate to use on longer distances. Angular field of view of the Key XM30 unit is 7.8?. If your sole purpose is to observe an object without a need of taking pictures or videos then this unit (Key XM30) is the one you are looking for.
Pulsar Axion Key XM30