With these, you don't need to worry so much about the exit pupil. This applies to roof prism binoculars and compensates for the small wave length shift that occurs with roof prisms. Oops, a new term. Binoculars fall into two basic designs. Porro prisms are wide-bodied with the objective lens and the ocular lens being offset.
Roof prisms are sleeker, and longer.
The objective and ocular lenses are in a straight line. Each has its advantages and disadvantages but when you purchase an upper end pair, your main concern should be how they feel in you hands. There are a few other considerations that are important. You will need to be able to focus quickly. Center focusing is the only way to go here.