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Exit Pupil info |
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DOGMAN
Optics Apprentice Joined: May/05/2006 Status: Offline Points: 52 |
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Posted: July/10/2007 at 11:52 |
When refering to exit pupil stats- this means how much light or how bright you can see an object thru a scope. I'm looking at the Leupold European 3-9x50(30mm tube) for dusk shooting. What is the exit pupil on these? I have three Leupold 1x4x20 scopes & These scopes are BRIGHT! & a very clear wide field of view. Why is that considering it is a small scope?
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Urimaginaryfrnd
MODERATOR Resident Redneck Joined: June/20/2005 Location: Iowa Status: Offline Points: 14964 |
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50mm divided by the power 9x gives a 5.5 mm exit eye pupil 50mm divided by the power 8x gives a 6.25 mm exit eye pupil BRIGHTER 50mm divided by the power 7x gives a 7.14 mm exit eye pupil BRIGHT AS IT GETS fully dialated your eye is about 7mm when young and less later in life. If you are having difficulty with the concept take a variable scope outside at dusk and look at it at each power setting same scope and see the difference.
1-4x20 scope --------
20mm divided by the power 1x gives a 20mm exit eye pupil 20mm divided by the power 4x gives a 5mm exit eye pupil relatively bright but by no means as bright as is possible 20mm divided by the power 3x gives 6.666 almost as bright as it gets. |
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"Always do the right thing, just because it is the right thing to do". Bobby Paul Doherty Texas Ranger |
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ND2000
Optics Journeyman Joined: January/29/2007 Location: United States Status: Offline Points: 308 |
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Dogman -
Most people > 30-35 years old can't use more than 5.5 mm of exit pupil anyway...as the previous posts suggests, the limiting factor when using scopes is generally your eye. I generally believe there is zero use for a 50 mm objective in a scope for this very reason.
Also keep in mind that brightness is the result of a number of factors other than exit pupil, and quality of glass is far more important.
ND2000 |
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You either get what you pay for or what you deserve.
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www.technika.nu
Optics Journeyman Joined: August/02/2005 Location: Sweden Status: Offline Points: 611 |
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I cannot agree that a Leupold 20mm is bright, not even a leupold 50mm is bright.
When you compare scopes daytime everyting is bright, you need darkness to compare the brightness of the scopes.
I cannot either agree that a 30-35 year old not can use bigger exitpupil than 5-5,5. Firsit it's generally considered that a 40 year old can use 6mm and that we loose 1mm every ten years from that. But there is huge indivdual differances. When it comes to the objective size, a 80 year old man can have full use of a 200 mm lens if the magnification is high enogh. There is really nothing wrong with bigger exit pupil than pupil as it can be tricky to have the head exactly correct behind the scope otherwise.
Regards TEchnika |
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Dale Clifford
Optics Jedi Knight Joined: July/04/2004 Location: United States Status: Offline Points: 5087 |
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exit pupil exists as a definition, brightness a factor of contrast and resolution and not necessaryily the same as luminance, illuminance, and emittance although in this forum they are used interchageably. then aside from the physical measurements that exist independant of the observer, which change with wavelength, sugarlevels, age etc, they are grouped into a thing called brightness. - a combination of a group of physical properties of the object and the observer. add to this the requirement of measurement at a threshold level darkness-- now stir this up with comparing devices that have not been formulated in the similar manner , wha la -- god I love testimonials cause thats all it boils down to. |
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Focus
Optics Master Conquistador!! Joined: June/05/2007 Location: Maine Status: Offline Points: 1006 |
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Exit pupil is an excellant measure of what power can be used without
exit pupil restrictions. Larger the objective the more power that can
be utilized.....more power moves the object closer to the eye and
allows better sight picture in low light. Reason euro's are all big on
hubble size objectives, bigger objectives move the scope higher on the
gun and tend to alter cheek weld as well.
Testimonials ........nahhhh..........real life comparisons with real eyes...............thats what its about......... focus |
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I Can See Clearly Now......<><
If Accurate rifles Are Interesting.....I've Got Some Savages That Are Getting Mighty Interesting...... |
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Dale Clifford
Optics Jedi Knight Joined: July/04/2004 Location: United States Status: Offline Points: 5087 |
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testimonials=opinions= everyone has at least one focus you state a measureable physical parameter as a guideline then state a subjective human guideline --which is it??? |
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glockpacker
Optics GrassHopper Joined: September/24/2005 Location: United States Status: Offline Points: 21 |
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hubble size objectives
Gotta remember that one! |
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Eric of Fort Lauderdale
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Focus
Optics Master Conquistador!! Joined: June/05/2007 Location: Maine Status: Offline Points: 1006 |
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Hmmmmmmm....that was pretty astute there cliff and you can use one and not the other?????? The answer is.......gasp!........BOTH....used in logical accordance with one another. You go do
testimonials.......I will use all different tools available to effectively
compare and evaluate optics.
But as far as opinions go.........you are right.....we all have one........mine is you are in left field.... past the fence focus Edited by Focus |
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I Can See Clearly Now......<><
If Accurate rifles Are Interesting.....I've Got Some Savages That Are Getting Mighty Interesting...... |
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Dale Clifford
Optics Jedi Knight Joined: July/04/2004 Location: United States Status: Offline Points: 5087 |
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the difficulty is in correlating the constraints in the physical measurement used in the conclusion--- this match is 1300 degrees but I'll take the lighter. your not using logical deduction or induction, merely the statistical proof. x% of shooters prefer dodge pickups your the one using testimonials -- my expression about loving testimonials is tongue in cheek Edited by Dale Clifford |
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Focus
Optics Master Conquistador!! Joined: June/05/2007 Location: Maine Status: Offline Points: 1006 |
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Uhhhh....Dale.......I never take your optics opinions serious.......its been tongue and cheek for quite a while now with me...............I'm glad to see you're loosening up..... i'm sure the dodge pick-up will have a lighter also....... focus Edited by Focus |
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I Can See Clearly Now......<><
If Accurate rifles Are Interesting.....I've Got Some Savages That Are Getting Mighty Interesting...... |
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