View Full Version : 1-4x's, why the small objective lens?
I am looking for a 1-4x or 1-6x range scope.I see that most all of them have are 24mm or 26mm. What is the reason for this? I have it down to 2 scopes that I would get. They are both Bushnells (see user name).. One is a 1-4x24mm the other is 1.5-6x42mm. They both have the same reticle.
What are the benefits of the smaller size? I can see it may interfere less when shooting both eyes open, is that the only reason? maybe less lens glare.. I have another AR set up as my "CQB" rifle with red dot sight forward mounted of the A2 style upper. This one however is a medium contour 16" flat top upper. I like the versatility of a 1x or 1.5x variable scope. The main use will be in mixed wooded and agricultural areas (mainly for close range coyote hunting). Thanks for any input
Because objective size on lower magnification scopes is based on exit pupil size. This equates to how much useable light the scope can gather. The average human eye can utilize about 5mm per magnification factor. So a 4X scope only needs an objective lens of 20mm to be able to transmit as much light as the eye can effectively use. With all other things equal, a 4X scope with a 32mm objective would appear no brighter than one with a 20mm objective. So anything over 20mm would be unnecessary.
Of course, not all scopes are equal and their light transmission abilities depend on construction and lens/coating quality. Two 4X20 scopes from different manufacturers, or scopes from the same manufacturer at different quality levels will transmit more or less light. There may be a point of diminishing returns, but you can never get a scope that's too good. It's not unheard of to pay more for the optic and mounts than the rifle they're mounted on.
thank you for the info. i think i'll go with the 1-4x24. i dont think the 6x will be a game changer. As for price, with 2 kids and a wife and going back to school on the post 9/11 gi bill its just not possible to put that much down on optics.
Specifications for Bushnell Trophy Series 1-4x24 with Illuminated Dot 30mm Tube Riflescope 731424M :
Power/obj. Lens (mm): 1-4x24
Reticle: 4A w/illum
Weight (oz. / g): 16.2/459
Field of view (ft.@100yds. / m@100m): 75/23@1x / 29/9@4x
Length (in. / mm): 12.7/323
Exit Pupil (mm): 22
Eye relief (in. / mm): 3.5 / 89
Click value (in@100yds./mm@100m): .25/7
Adj. range (in@100yds. /m@100m): 100/2.8
Mntng length (in. / mm): 4.5/114
Features of Bushnell Trophy Series 1 - 4 x24 with Illuminated Dot 30mm Tube Rifle scope:
* Multi-coated optics
* Amber-Bright high-contrast lens coating
* One-piece tube
* 100% waterproof, fogproof and shockproof
* Dry-nitrogen filled
* 1/4 M.O.A. fingertip, audible/resettable windage and elevation adjustment
* Fast-focus eyepiece
Im pretty sure lens quality matters alot more. I have a 2.5-10x24mm nightforce and its much clearer and brighter than bigger objectives even during dusk.
I ordered one and it is being shipped. thanks the info. But i think will be a good buy. ill post some more once i get it mounted and zeroed. i'll be mounting it in a burris PEPR it seems like a good mount not flimsy in the least and well built. but i dont like the rails on the top rings but oh well. i'll try some pics maybe..
I must say I am very happy with this scope. It is very bright and clear. I really like the 4A reticle with the illuminated red dot. Its not a true 1x but most all aren't, but I can clearly see the cat sitting on the back of the chair from the couch. less than a 1.5 i looked at. I zeroed today and the adjustments were precise didn't take my camera so I only have the one 3 shot group target photo, but at 50 yards it passed the square test, didn't fog either. The red dot was visible except it washed out on the snow but picked up again in the trees, brush or target. I didn't get to put a lot through it (200 rounds) but it kept zero, and on 1x at 25 yards it was great for rapid fire. I don't think I'd be anymore happy if I had paid $1,500 more than the $135 I spent on it. I tried a reticle pic but my camera has auto focus only and wouldn't focus looking through the scope. I may try again later.
How is the field of view on the 1-4's? :)
On 1x both eyes open gives a good FOV...Do i sense sarcasm? or is that a friendly smile?
This is an ok pic but not that great. From my position to the wall is 14 feet
I want to use my tax return on a Nightforce 1-4 on my 16" middy. :cool:
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