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Technical Objective size question |
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Mike52
Optics GrassHopper Joined: November/21/2011 Status: Offline Points: 19 |
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Posted: September/30/2013 at 06:01 |
Given 3 variable scopes of identical manufacture, glass, coatings, quality etc. one having a 56mm objective, one having a 50mm objective and one having a 42mm objective all set at 4X the optical calculation for exit pupil says that at that 4X the exit pupil's will be 14 mm, 12.5mm and 10.5mm respectively. All of which are larger than the maximum 7mm dilation of the normal human eye in the dark.
If all your hunting is on big game under 100 yards and you never set your scope over 4-5X what if any is the point in a 50 or 56mm objective? |
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bugsNbows
Optics God bowsNbugs Joined: March/10/2008 Location: North Georgia Status: Offline Points: 11200 |
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IMO, no point for the big Hubble-like scopes based on your scenario.
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If we're not suppose to eat animals...how come they're made of meat?
Anomymous |
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Shenko
Optics Apprentice Joined: April/20/2008 Location: WA Status: Offline Points: 249 |
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At 4x or 5x, a 32mm or 35mm objective will work as well as anything.
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Kickboxer
MODERATOR Moderator Joined: February/13/2008 Status: Offline Points: 23679 |
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Opinion,untempered by fact,is ignorance.
There are some who do not fear death... for they are more afraid of not really living |
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supertool73
Optics God Superstool Joined: January/03/2008 Status: Offline Points: 11814 |
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It has been posted by night time hog hunters that big objectives do help all else being equal.
One particular brand that is talked about is the Trijicon Accupoint 3-9x40 vs the 2.5-10x56. Those that have both do say the 56 is brighter and more usable at night and in low light. But most of them prefer the 3-9x40 because it is lighter and smaller. |
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Lifetime warranty and excellent customer service don't mean a thing when your gun fails during a zombie attack.
"A Liberal is a person who will give away everything they don't own." |
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Alan Robertson
Optics Master Joined: October/31/2009 Location: Oklahoma Status: Offline Points: 1763 |
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"Garg'n uair dhuisgear"
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Mike52
Optics GrassHopper Joined: November/21/2011 Status: Offline Points: 19 |
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it is puzzling as some claim the big objectives help (all else being equal) but other's see no difference. The technical argument says they would not be of much help provided the exit pupil was all that it took to illuminate your eye pupil.
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Shenko
Optics Apprentice Joined: April/20/2008 Location: WA Status: Offline Points: 249 |
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A bigger objective makes a big difference, but not at 4X. A 50mm objective lens lets twice as much light into the scope than a 35mm lens. To take advantage of that light, you have to adjust the magnification so the exit pupil of the scope is equal to the entrance pupil of the eye.
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Kickboxer
MODERATOR Moderator Joined: February/13/2008 Status: Offline Points: 23679 |
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There is no doubt the larger objective allows more light to enter the scope. Exit pupil size is not the "final arbitor" of "apparent brightness". Your question is too generic and relative... there are a number of variables that come into play and can't really be addressed based upon your question parameters. Volumes could be written, and have been, on this type of scenario.
Based upon your stated requirements, the smaller objective should provide all the "brightness" you need. That does not translate to other, more complex, scenarios
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Opinion,untempered by fact,is ignorance.
There are some who do not fear death... for they are more afraid of not really living |
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supertool73
Optics God Superstool Joined: January/03/2008 Status: Offline Points: 11814 |
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Being able to "zoom" in closer on the game will make it appear brighter as well as you will be able to see more detail because of the added magnification. This is another area where a larger objective will make a difference as you will have a larger exit pupil.
Hopefully Charles "ccoker" will comment on this as he has a lot of in the field experience in low light and night hunting with a large number of scopes high quality scopes.
This is always one of the difficulties with asking these types of questions. First off we have no real idea if said person has any idea what to look for. Are they really using comparable scopes. Was the small objective scope a Swaro and the large objective a Bushnell 4200? Do they really understand the technical aspects of the question? I admit my technical knowledge is very limited vs people like Kickboxer, Koshkin, Rifledude, etc. |
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Lifetime warranty and excellent customer service don't mean a thing when your gun fails during a zombie attack.
"A Liberal is a person who will give away everything they don't own." |
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Mike52
Optics GrassHopper Joined: November/21/2011 Status: Offline Points: 19 |
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I cannot see how my question would be generic? 3 scopes of identical glass and coatings but with different objective sizes? Say 3 Zeiss victory scopes 1-4 x25, 1.5-6 x42, and 2.5-10 x50 all manufactured on the same day at the same time. All set at 4x. Do I know what to look for, yes for an image as the lights go off. I am getting the answer that it is more of a feeling than a hard fact regards this question.
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Shenko
Optics Apprentice Joined: April/20/2008 Location: WA Status: Offline Points: 249 |
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You might find it informative to run those numbers through the Low-Light Performance Calculator at scopecalc.com.
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Code4
Optics Apprentice Joined: July/11/2010 Location: Australia Status: Offline Points: 76 |
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Is there a relationship between objective size and FOV ? I ask because I don't know.
I know FOV has a big impact on my 'perception of usefulness' with many scopes.
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Tye
Optics GrassHopper Joined: October/29/2013 Location: N. Cal Status: Offline Points: 9 |
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Here is one easy advantage you can state without a doubt for bigger objectives:
The bigger the objective the greater the ability to resolve detail of the viewed object. Cheers, Tye |
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