Can anyone explain to me the difference in scope powers suck as 4-12x50, 6-18x50, etc. What does each number mean? Thank you.

Sure, the 4-12 is variable power. From 4 power up to 12 power. That is numbers of magnification. The last number 50, is the size of the objective lense in millimeters. The lense closest to the muzzle. The bigger the objective lense, the more light it lets in. So it will be a brighter picture during lowlight conditions. Hope this helps some.

Thanks. So basically a 6-18x50 is slightly more powerful than 4-12x50 but they both let the same amount of light in. I guess the 6-18 would be better for open field shots and 4-12 for more wooded shots, right? I have a friend who has a Swarovski 6-18x50 and says I need to get one, but I am trying to make sure that would be best for me. Thanks again.

This is only true if both scopes have identical lenses and coatings.A scope with a smaller objective lens can be brighter if higher quality lens coatings are used.

That scope will cost big bucks. Good quality but expensive. I would suggest looking at the Leupold line. They are great optics, but don't cost quite so much.

Jbradley, what caliber are you hunting with and is it mostly long distance shooting? If you plan on hunting in the bush at short distance the 6-18 wouldn’t be your best choice. You would have to go with a 3-9 or the 3-10 Swarovski scope instead.

Scope powers above 12 power are getting into the area of becoming useless on a big game rifle or st least should only be used on very specialized long range big game rifles.

Above 12 power you are in the varmint and target magnification range where you need the extra magnification to precicely place bullets on very small targets.


Points to consider when purchasing a scope for a rifle................

What is its intended purpose? General big game hunting, varmint, bench rest, loooong range target, etc...

What distances do you expect to be shooting? As the power increases the field of view decreases. So, closer ranges need less magnification so if you expect shots at 25 yards then you need a variable power scope of 3 power or less on its lowest setting. A scope that only gets down to 6 power will noly make it more dificult to find your target as the target gets closer to you.

Do you anticipate any shots needing to be taken quickly. A high power scope will almost certainly cause you to miss an oportunity.

How heavy do I want my scope to be? Remember that the larger the lenses and the higher the magnification the heavier the scope will be.

WHat kind of rifle will you be mounting it on? You don't want a huge scope on a light weight compact rifle just like you son't want a small compact scope on a "beanfield" rifle.

Consider if you will be useing it in low light conditions.............. If so, a high magnification will transmit less light to your eye than will a lower power scope. This is because as the power of the scope increases the exit pupil of the scope gets smaller and smaller. An exit pupil is the diameter of the "circle of light" a scope transmits when it reaches your eye and is in focus. The smaller the exit pupil the less light is transmitted to your eye. To find the exit pupil divide the objective lense diameter by the power number. Example.... 9 power and a 40mm objective will give you an exit pupil size of 4.4mm.. The optimal thing you want to happen is to have an exit pupil the same size or slightly larger than the maximum eye pupil of your own eye. Of course this is impossible to achieve on a variable power scope but there is no sense in purposely making it worse than it has to be. Most adults have an eye pupil size of about 6mm in very low light. So having a scope such as a 6-18X50 set on 18 power will only give you an exit pupil size of 2.7mm. This means that about 60% of your eyes ability to see brighter will not be used.

The quality of glass. The higher quality the glass the clearer, sharper and brighter the image will be when it reaches your eye.

The type and quality of coatings. Same thing applies here as it does the glass quality.



I hope this helps you choose a scope that will fit your needs and not what someone else thinks you need.

I have a Weatherby .300 wthby magnum, hunting in both wooded and open field.

I would mount a Zeiss Conquest 3.5-10x44. Go to www.eurooptic.com Good luck.

jbradley, if you are looking for a scope to be used in wooded areas or dense foliage, I would suggest a 1.5 x 5 or 2.5 x 8. More then enough magnification for long shots in openings or on powerlines, but still a very flexible for dense cover. The 4.5 power is just a bit strong for very dense foliage. One other thing to consider is the 50mm objective. It will definitely let in more light, but sometimes that additional light can cause flare on the lense. I would recommend a 2.5 x 8 x 32 as an excellent, all purpose scope.
Good hunting....