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Exit Pupil info

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DOGMAN View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DOGMAN Quote  Post ReplyReply Direct Link To This Post Topic: Exit Pupil info
    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 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Urimaginaryfrnd Quote  Post ReplyReply Direct Link To This Post Posted: July/10/2007 at 12:14

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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ND2000 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ND2000 Quote  Post ReplyReply Direct Link To This Post Posted: July/10/2007 at 12:24

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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www.technika.nu View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote www.technika.nu Quote  Post ReplyReply Direct Link To This Post Posted: July/10/2007 at 13:40

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 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dale Clifford Quote  Post ReplyReply Direct Link To This Post Posted: July/10/2007 at 15:35

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 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Focus Quote  Post ReplyReply Direct Link To This Post Posted: July/10/2007 at 18:53
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.........


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If Accurate rifles Are Interesting.....I've Got Some Savages That Are Getting Mighty Interesting......
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Dale Clifford View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dale Clifford Quote  Post ReplyReply Direct Link To This Post Posted: July/11/2007 at 10:09

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 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote glockpacker Quote  Post ReplyReply Direct Link To This Post Posted: July/11/2007 at 11:44

hubble size objectives

 

Gotta remember that one! 

Eric of Fort Lauderdale
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Focus View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Focus Quote  Post ReplyReply Direct Link To This Post Posted: July/11/2007 at 13:48
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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If Accurate rifles Are Interesting.....I've Got Some Savages That Are Getting Mighty Interesting......
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Dale Clifford View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dale Clifford Quote  Post ReplyReply Direct Link To This Post Posted: July/11/2007 at 15:21

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 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Focus Quote  Post ReplyReply Direct Link To This Post Posted: July/11/2007 at 17:23
Originally posted by Dale Clifford Dale Clifford wrote:


  my expression about loving testimonials is tongue in cheek



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
I Can See Clearly Now......<><

If Accurate rifles Are Interesting.....I've Got Some Savages That Are Getting Mighty Interesting......
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