Just be aware that there are binoculars and then there are binoculars.
Those with the collimation done by small screws in the housing are the cheapest of the lot. Consider what happens when you tilt a prism to incoming light, you get a spectrum (even in a right angle prism). This will put chromatic aberration into your image, elongate the image and give double images. There is more to collimation than just "tweaking" the prisms. There is leaning field, prisms are not perpendicular, or just not polished to the correct angle. Consider those prisms with the coll screws in the housing, you drop them you will either chip the prism or shear off the roof! New prism needed.
There is more to collimation than meets the eye!!
