As far as scopes go I've always been a fan of Leupold, but these days there are many good choices when it comes to optics.

One factor many don't consider when buying a scope is the exit pupil in low light conditions. You can always use a sun shade in bright conditions.

A 40mm objective lens will give you a 13.3 mm exit pupil at 3 power, it's reduced to a 10 mm exit pupil at 4 power.

If you go to a 50mm objective lens at 3 power you will have a 16.6mm exit pupil, and a 12.5 exit pupil at 4 power

The differences in exit pupil can be a huge factor in low light conditions. The average human eye will have a 5 to 7mm pupil in low light conditions. A large exit pupil from your scope is a great advantage.

Exit pupil is just one thing to consider when buying a scope, but IMHO it's one of the main things to consider when making the choice of power, and objective lens.

http://www.shootingtimes.com/2011/01...cpupil_061907/