Re: 40 v 50 v 56 mm Objective Lens
I never did make very good grades in optics nor E & M. I still have my optics book but hate to go and open it (bad memories).
As we previuosly discussed, I have an old scope that I can no longer see through. I had thought that it was just the scope was old and maybe the coatings had gone bad. It is really irritating to find out that it is me that has gotten old.
Anyway, I like your bottom line calculation although I do not agree with your conclusion about the 56. If I remember correctly someone is making a 72mm obj which gets you up to 10.3X. My conclusion is that if your eyes are going downhill then spend money on optics to compensate plus anyone who has ever tried to put horns on a deer or elk late in the day knows that it is not the determination that the animal is a deer or elk, it is the resolution of the antlers. You cannot put the crosshairs on it and a finger on the trigger unless you can resolve antlers. It has been a long time since I have hunted elk but it is my understanding that nowdays some states regulate by number of point on the antlers ( cow ,spike, mature bull ). This makes things very critical at long range. Maybe if you are buying a scope for a gun that is intended for whacking rocks, pdogs or chucks this is not very important.
The Smokin Fur Rifle Club