Scope Noob question about magnification

Bubba Phett · August 27, 2013, 08:35 AM

I am a scope noob and I have a question about scope magnification.

I recently purchased a few different 4x scopes to tinker with. I noticed that although they are all fixed 4x they seem to have different 'effective magnification'.

If I point these scopes at my truck from about 60 feet the truck appears a different size in each scope. With one scope, the tailgate of the truck basically fills up my whole picture. On another scope, the truck appears much smaller and I can see the whole truck and surrounding area.

Am I being fooled because one scope has a much larger FOV than the other so the truck just seems to be a different size or do scopes have a listed magnification specified as well as an 'effective' magnification that is the sum of all parts. Or is magnification not what I think it is?

Go easy. Thanks.

jmr40 · August 27, 2013, 09:32 AM

That is normal. Manufacturers often round off to the closest full power. Because of different manufacturing techniques Brand A might actually be 3.87X. Brand B might turn out to actually be 4.17X. To keep things simple they call them all 4X. Sometimes you can look at manufacturers specs and they will give the true magnification in the fine print.

NoSecondBest · August 27, 2013, 09:50 AM

Your scopes could have two different "fields of view". That means that one scope may allow you to see x amount of feet at a given distance and the other scope allows y field of view at the same distance. Look up the fov for each scope and I'll bet it's different. Question: do both scopes have the same size lenses front and rear? That's a pretty quick way to tell.

Bubba Phett · August 27, 2013, 11:24 AM

JMR -
Thanks, that's pretty much what I wanted to know.

NoSecondBest -

Yes they have different fields of view. They all have different lens sizes.

One is 4x30 - VERY low end scope, specs appear to be a closely guarded trade secret - eyepiece is smaller than objective

One is 4x32 -
eyepiece looks to be slightly smaller about 29-30mm
Field of View 15f @ 100Y

Last one is 4x24
eyepiece is bigger than the objective on this one coming in at about 30mm
Field of View 70m @ 1000m = 23feet in 109yards (I think?)

With the first two scopes the truck looks pretty big and fills up my FOV.

The last scope has a bigger eyepiece than objective and has a much wider field of view. The difference is pretty dramatic even at close range. I think that is what is throwing me off.

August 27, 2013, 08:35 AM	#1
Bubba Phett Junior Member Join Date: August 27, 2013 Posts: 9	Scope Noob question about magnification I am a scope noob and I have a question about scope magnification. I recently purchased a few different 4x scopes to tinker with. I noticed that although they are all fixed 4x they seem to have different 'effective magnification'. If I point these scopes at my truck from about 60 feet the truck appears a different size in each scope. With one scope, the tailgate of the truck basically fills up my whole picture. On another scope, the truck appears much smaller and I can see the whole truck and surrounding area. Am I being fooled because one scope has a much larger FOV than the other so the truck just seems to be a different size or do scopes have a listed magnification specified as well as an 'effective' magnification that is the sum of all parts. Or is magnification not what I think it is? Go easy. Thanks.

August 27, 2013, 09:32 AM	#2
jmr40 Senior Member Join Date: June 15, 2008 Location: Georgia Posts: 10,809	That is normal. Manufacturers often round off to the closest full power. Because of different manufacturing techniques Brand A might actually be 3.87X. Brand B might turn out to actually be 4.17X. To keep things simple they call them all 4X. Sometimes you can look at manufacturers specs and they will give the true magnification in the fine print.

August 27, 2013, 09:50 AM	#3
NoSecondBest Senior Member Join Date: December 7, 2009 Location: Western New York Posts: 2,736	Your scopes could have two different "fields of view". That means that one scope may allow you to see x amount of feet at a given distance and the other scope allows y field of view at the same distance. Look up the fov for each scope and I'll bet it's different. Question: do both scopes have the same size lenses front and rear? That's a pretty quick way to tell.

August 27, 2013, 11:24 AM	#4
Bubba Phett Junior Member Join Date: August 27, 2013 Posts: 9	JMR - Thanks, that's pretty much what I wanted to know. NoSecondBest - Yes they have different fields of view. They all have different lens sizes. One is 4x30 - VERY low end scope, specs appear to be a closely guarded trade secret - eyepiece is smaller than objective One is 4x32 - eyepiece looks to be slightly smaller about 29-30mm Field of View 15f @ 100Y Last one is 4x24 eyepiece is bigger than the objective on this one coming in at about 30mm Field of View 70m @ 1000m = 23feet in 109yards (I think?) With the first two scopes the truck looks pretty big and fills up my FOV. The last scope has a bigger eyepiece than objective and has a much wider field of view. The difference is pretty dramatic even at close range. I think that is what is throwing me off.