The Twilight Factor

Read this tip to make your life smarter, better, faster and wiser. LifeTips is the place to go when you need to know about Redfield Scopes and other Hunting Scopes topics.

What is the Twilight Factor?

The Twilight Factor

Unlike the old Twilight Zone, the Twilight Factor is how scopemeisters state the light-gathering ability of a scope.Take out your calculators and follow the formula to get to the Twilight factor:

First you multiply the size of the objective lens by the magnification power, then find the square root of the result.(See, I told you you'd need a calculator.) For example, the twilight factor on a variable power scope set on 10X with a 40mm objective lens is 20.
Why? Because 10 x 40 is 400 and the square root of 400 is (anybody?) 20.

The twilight factor is a purely mathematical equation that doesn't take into consideration the quality of the lens nor the coatings. So, you can leave your calculator at home when trying to decide on a new scope.

   

Comments

Nobody has commented on this tip yet. Be the first.



Name:


URL: (optional)


Comment:


Not finding the advice and tips you need on this Hunting Scopes Tip Site? Request a Tip Now!


Guru Spotlight
Sherril Steele-Carlin