Re: 44 - 50 objective
bjjohnson,
Before losing any sleep over which Zeiss Conquest to buy, the 44mm or the 50mm for low light use, please consider the following:
None of the Conquests your looking at feature a illuminated reticle. So in my experience, in low light without illumination, in most cases you lose the reticle, way before you lose sight of the target your seeking.
The Zeiss #4 and #20 reticles are thick and will provide you an aiming point in low light, longer than the #43 or the Rapid Z's.
So objective diameter is only one part of the equation. You must also consider reticle design and thickness.
Best of luck,
Bob