Vortex 18X56 vs 20X56

[Bowman]

Hi Adam

In regards to a spotting scope.
2 cents here.
If weight is manageble, I suggest to
Go with the bigger objective lense.
60 mm(2.3 in) vs
85 mm(3.3 in )
1 inch larger object lense is a big deal. Larger exit pupil. Better visibility at higher magnification.
Better light gathering at low light.

With the same quality glass
If weight and cost was no object
If I could carry it, and I had the pocket book
That's what I would do.
LB

 

[Bowman]

So with my astronomy hobby.
We try to get the biggest objective lense as possible. Of course we don't
Have to carry it up and down mountains. So weight not an issues.
With the quality of glass, there is give or take on the focal length of the occular eye piece. Smaller the focal length, higher magnification.
The larger the view, but less clear.

My point is this
The larger objective lense will allow
Higher magnification, more light gathering, clearer view. Even at low
Light.
Best
LB

 

[Bowman]

Playing with my toys at home.
Going from 10x to 20 x
50mm vs 60mm made a difference.
Because of the quality of my equipment. I could make out detail at one mile.
At 10x I could see game but not in detail.
At 20x it was very detail but I need more practice. For sizing deer with antlers.
LB