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50mm and sometimes bigger front glass?

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Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: July/31/2013 at 16:31
JD548 View Drop Down
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whats the deal with all these big glass scopes?

every time i get a sale circular there are like a dozen or so scopes with 50mm glass.

in theory the big glass equals more light.

however my low power 1-4x scopes seem to do well in the dark except the 1-6x china doll thwhen turned up to 6x.

the 35mm vortex diamondback seems as bright on 6x as a 40mm tube so whats up?

does the big "58 ford  headlight" glassed scopes help at night or something?

is bigger really better? or is there some drawback that limits how much light a tube can draw past a certain point?
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: July/31/2013 at 17:37
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There is some good info in this post. I would read these.

http://www.opticstalk.com/exit-pupil-light-transmission-30mm-vs_topic5023.html
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 00:31
Oldtrader3 View Drop Down
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Read about exit pupil and twilight factor (a little) and realize that European's hunt at night from stands in the pitch dark and use objective lenses up to 60mm.  None of this affects the average whitetail hunter, who hunts until 1/2 hour after sunset or before dawn.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 08:21
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I have found the 40-50 to bee unobtrusive.


KB how is that 72 working out for you and what was the brand of that scope and how did you ever get that in your hands.
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Are you speaking of the 6-24x72 HENSOLDT that my wife purchased for me???  I have not hunted with it yet, but have carried it around on the 338 quite a bit... just getting a feel for it.  It is not a burden and it is exceptional in all legal hunting conditions.  Sometimes I just go walk around in the woods around my house, hoping a coyote or some other predator will come around... no joy yet.  I intend to hunt with it this year.  This is going to be a BIG hunting year for me.  I convinced my wife that we need a new refrigerator AND a freezer and that we should keep the "old" refrigerator.  Now, I just have to fill them...
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 09:16
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Those huge objective scopes are much more commonplace in countries outside the US due to different hunting laws and customs. If our hunting laws here in the States allowed us to hunt BG all night long, I'd probably suffer a 56mm scope. Until then, I've been more than happy with the light transmission I get from 50mm and smaller objective scopes. Given this, I'll take a less obtrusive, less expensive, lighter, lower mounted scope vs. marginally improved light transmission that only benefits me during times I can't legally hunt anyway.

I do hunt feral hogs and predators at night on occasion, though. That is legal where I live because neither hogs nor predators are considered regulated game animals. For that application, I could benefit from a 56mm and larger objective. But, since I don't have rifles dedicated only to hog and predator hunting, and since I use kill lights and night hunt during bright moonlight, I've never been willing to accept the tradeoffs of going larger than 50mm. Beyond 50mm is where most scope mount systems require high mounts. In general, I just dislike the objective bell on my scope to be significantly wider than my rifle's forend and it becomes more difficult to fit 2 rifles in a 2-gun hard case when the scopes protrude too high above the rifles. For these reasons, most of my hunting rifles wear 32 - 44mm objectives, and I've never felt handicapped by that fact.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 10:01
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Hunt some trees is what I thought the motto here was...???Big Grin
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 10:16
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If you take the size of the objective divided by the magnification you get exit pupil.  So say you have a 50mm an a 40mm scope on 10x.  Your 50mm has an exit pupil of 5 and the 40mm has an exit pupil of 4.  The image will appear brightest when the exit pupil is equal , or larger than, the pupil of the eye.  The human eye pupil can change in size from roughly 2mm to 7mm depending on age and lighting conditions. During a super bright day when your eye pupil is smallest, you most likely will not notice any difference.  During low light conditions where you eye is dilated you are more likely to notice a difference.  It also depends on what magnification you have your scope on, the lower the magnification the brighter the image, hence the larger exit pupil.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 10:46
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Originally posted by 338LAPUASLAP 338LAPUASLAP wrote:

Hunt some trees is what I thought the motto here was...???Big Grin
Bad, bad, bad... It was defective...
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 11:40
JD548 View Drop Down
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lets just say --

if one was to shoot feral hogs that was attacking his crops at night and one wanted a scope that could really suck in the light  would a 50mm or bigger be better?

i'm not talking a deer hunting scope for deer season. i'm talking a night-time pest control deal--

some of the 50s ain't that much more weight, only the ford headlight sticking out the end makes um kinda tall--LOL!
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 11:52
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Originally posted by Kickboxer Kickboxer wrote:

Originally posted by 338LAPUASLAP 338LAPUASLAP wrote:

Hunt some trees is what I thought the motto here was...???Big Grin
Bad, bad, bad... It was defective...
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 11:53
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Originally posted by Hunter22 Hunter22 wrote:

If you take the size of the objective divided by the magnification you get exit pupil.  So say you have a 50mm an a 40mm scope on 10x.  Your 50mm has an exit pupil of 5 and the 40mm has an exit pupil of 4.  The image will appear brightest when the exit pupil is equal , or larger than, the pupil of the eye.  The human eye pupil can change in size from roughly 2mm to 7mm depending on age and lighting conditions. During a super bright day when your eye pupil is smallest, you most likely will not notice any difference.  During low light conditions where you eye is dilated you are more likely to notice a difference.  It also depends on what magnification you have your scope on, the lower the magnification the brighter the image, hence the larger exit pupil.


In general, yes.

What really factors into the exit pupil size is the effective aperture size, which may or may not be the same as the "specification" objective diameter. If the scope is stopped down internally, you may not actually be getting the full benefit of the objective lens diameter.

Also, a larger exit pupil isn't the lone contributor to low light performance. Besides image quality and transmission values of the optic, magnification also matters. A "bright" optic with a huge exit pupil at low magnification may be inferior in terms id'ing your target to a smaller exit pupil at higher magnification due to greater resolving detail. The best low light performance comes with a balance of both -- sufficient magnification for good detail and sufficient exit pupil size for the magnification used, combined with great optics.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 12:16
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http://www.samplelist.com/-P63100.aspx

how does this 50mm 3-9x look for night time wild hog zapping??
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 12:35
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Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 13:02
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Originally posted by RifleDude RifleDude wrote:

Originally posted by Hunter22 Hunter22 wrote:

If you take the size of the objective divided by the magnification you get exit pupil.  So say you have a 50mm an a 40mm scope on 10x.  Your 50mm has an exit pupil of 5 and the 40mm has an exit pupil of 4.  The image will appear brightest when the exit pupil is equal , or larger than, the pupil of the eye.  The human eye pupil can change in size from roughly 2mm to 7mm depending on age and lighting conditions. During a super bright day when your eye pupil is smallest, you most likely will not notice any difference.  During low light conditions where you eye is dilated you are more likely to notice a difference.  It also depends on what magnification you have your scope on, the lower the magnification the brighter the image, hence the larger exit pupil.


In general, yes.

What really factors into the exit pupil size is the effective aperture size, which may or may not be the same as the "specification" objective diameter. If the scope is stopped down internally, you may not actually be getting the full benefit of the objective lens diameter.

Also, a larger exit pupil isn't the lone contributor to low light performance. Besides image quality and transmission values of the optic, magnification also matters. A "bright" optic with a huge exit pupil at low magnification may be inferior in terms id'ing your target to a smaller exit pupil at higher magnification due to greater resolving detail. The best low light performance comes with a balance of both -- sufficient magnification for good detail and sufficient exit pupil size for the magnification used, combined with great optics.


You are spot on, I just didn't want to go over his head.  He was referring to how the Objective Size affects light, there are defineatly more factors than just the size of the Objective that go into low light performance.

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 14:46
JD548 View Drop Down
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that meostar R1 30mm  looks about perfect. only thing is it costs a whole $1K--

i may just trap them . 

costs $$ to trap them mostly in the  feeding um out but there is less waste.

and i suppose i could use a few TONS of pork sausage--
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 19:07
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Originally posted by JD548 JD548 wrote:

lets just say --

if one was to shoot feral hogs that was attacking his crops at night and one wanted a scope that could really suck in the light  would a 50mm or bigger be better?



All else being equal... yes, bigger is better for ultimate low light performance.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: August/02/2013 at 23:23
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Just make sure that the exit pupil is 5mm or larger.
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