Just a small comment about optics, even with top quality 20x mag needs 50mm objective to give you the light that makes the image look "normal" 50x with 50mm would seem dark and difficult to define, your not Pysicaly going to get 24x with less than 50+ mm objective.
Forget for a second about guns, best bird watching binocs are 8x42, not much magnification and a very large objective lense, Thing of telescopes with 200mm Lenses they only magnify 30 or 40 times max.
BUT there is good news, the human eye can "see" more detail with MORE light, try a 12x50 vrs 20x50 , your EYE will see MORE @12x50 then it does at 20x50 because each photon receptor cone in your eye is getting more info!
Hence why surgeons use HUGE lights ... it gives the virtual effect of x2 mag, more light in your eye means better image, dont think that 30 to 40 x mag is any good at all without HUGE optics to get the light in.
Fox