Scope basics question

[chinaboy]

I know the what scope to buy topic has been covered before.  I'm wondering what the 3x32 , 4x40, etc...means?  What makes a better scope than not?  And what scope range is usually used for a pellet gun?  What size mount do you use for a crosman steel breech?

[quickster47 †]

I know the what scope to buy topic has been covered before.  I'm wondering what the 3x32 , 4x40, etc...means?  What makes a better scope than not?  And what scope range is usually used for a pellet gun?  What size mount do you use for a crosman steel breech?

The 4 means the level of zoom, which is 4 times.  The 40 stands for the millimeters of viewing range that you have at the exit of the scope.  The ocular lens you look out of will be 40 mm.  That 40 mm is often called the objective lens.

The glass used in the more expensive scopes is usually top quality with no flaws.

There is also a 1" diameter tube and a 30 mm diameter tube.  Supposedly the 30 mm tube has more light gathering capabilities since it is larger.  But then it also depends on the quality of the optics.  Larger tube allows them to use cheaper optics.  So it is a trade off.

Range is subjective.  Depends on what YOU want to shoot.

Personally, I use BKL scope mounts.  Available here; http://www.bkltech.com/default.asp or at Pyramyd Air.

Carl

[chinaboy]

Thanks Carl.  I appreciate your help.

I'm still confused as to what size mount I need for my 1377.  Do I want a 3/8 mount?   

[breakfastchef]

If you have installed a steel breech from Crosman or other vendors, you would want a 3/8" (or 11mm) mount for your optics. These breeches have the 3/8" grooves.

[Smaug]

If you divide the magnification into the objective lens diameter, you get a brightness factor. There's a more official name for it, but I can't think of it right now.

So for a 4x32 scope, the brightness factor would be 8. Nice, bright image. They also make 4x40s.

Compare that to a 10x40, which has 2.5 times the magnification, but the image is only half as bright. Harder to see the target in low light, harder to see the crosshairs, etc.

That's part of why the high end target scopes are always 50mm objectives. Because by the time you zoom out to 24x and above, you need all the brightness you can get.

[JEBert]

If you divide the magnification into the objective lens diameter, you get a brightness factor. There's a more official name for it, but I can't think of it right now.

I'm not sure about scopes, but on a pair of binoculars, if you divide the size of the objective lens by the power factor, you get the size of the "Exit Pupil".  It is the diameter of the area of light coming through the ocular lens.  The largest size a human pupil can dilate to is 7mm.  So, if you want a pair of binoculars for nighttime use, get a 7X50.  Any more than that and your eyes cannot make full use of it.  However, 7X50's are pretty large and heavy so most of us end up with good daytime binoculars.
Cheers,
Jerry

[Colt25]

If you have installed a steel breech from Crosman or other vendors, you would want a 3/8" (or 11mm) mount for your optics. These breeches have the 3/8" grooves.

Or you could use this: http://centerpoint.crosman.com/accessories/459MTC
Wobbly, but they do work.