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50mm vs. 40mm Objective

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Category: Scopes
Forum Name: Rifle Scopes
Forum Description: Centerfire long gun scopes
URL: http://www.opticstalk.com/forum_posts.asp?TID=46290
Printed Date: July/07/2020 at 21:42
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com


Topic: 50mm vs. 40mm Objective
Posted By: EdSy
Subject: 50mm vs. 40mm Objective
Date Posted: May/07/2020 at 05:50
Hi:  This is my first post.  I've been reading the forum for several weeks, while shopping for a better dawn/dusk scope for my deer rifle.  I hunt whitetail deer in the woods from tree stands.  I've used mostly Leupold scops for decades.  They work fine, but recently have wondered how much benefit I might realize if I move up to a 50mm objective.  At the same time, I'd upgrade to a VX-3 or VX-3i model.  I understand exit pupil, and its "shrinkage" as magnification increases for a given objective lens diameter.  Since most of the deer will be at 100 yards or less, having a variable scope set at its highest power is not necessary.  So, my question is: how much brighter would a 50mm set at about 7X be, than a 40mm set at around 5.5X? These magnifications were chosen to realize a 7mm exit pupil in the respective scopes. Many thanks, Ed

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-Ed



Replies:
Posted By: Kickboxer
Date Posted: May/07/2020 at 08:03
Light transmission is the advantage of 50mm vs 40mm... under your hypothetical, you would have roughly the same brightness at the higher power with 50mm as the lower power at 40mm... all other factors being equal (glass quality/coatings, design, etc).  You lose some depth of field with the 50mm.   The larger objective will also require a bigger, heavier, less wieldy (to some) scope and can create some issues addressing the scope/rifle.  
For your purposes, the 40mm will probably meet every need.  Remember, numbers on paper do not necessarily translate to visual perception.  Just because numbers are "better" does not mean the eye can perceive or translate it.  



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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


Posted By: koshkin
Date Posted: May/07/2020 at 15:24
There is an advantage to a 50mm objective, but under 100 yards, I do not know if I would necessarily be going bigger for regular hunting hours use.  If you shoot pigs in the middle of the night, that's a different ballgame.

If you are looking to get better performance, I would probably be inclined to stick with the 40-42mm objective and step up to something with higher optical quality.

ILya


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Posted By: Shenko
Date Posted: May/07/2020 at 15:25
In that scenario, the 50mm at 7x will be significantly brighter than the 40mm at 5.5x. For better dusk/dawn performance, go with the bigger objective, and experiment to find out what magnification works best for you.


Posted By: Kickboxer
Date Posted: May/07/2020 at 16:47
If you use 5.5x with a 50mm objective, you will definitely see a brighter "picture".  At 7x, most will not be able to recognize a difference.  

Here is Leupold's version (since you are looking at their scopes) of it (however, they DO have their numerator and denominator reversed):

https://www.leupold.com/leupold-core/core-knowledge/articles/top-5-optics-myths-explained - https://www.leupold.com/leupold-core/core-knowledge/articles/top-5-optics-myths-explained


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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


Posted By: Travis299
Date Posted: May/23/2020 at 07:46
I use my M70 for deer hunting and put a 3x9 - 50 mm Burris E1 scope on which I really like.  If I were looking for a new scope this is one that I would purchase.  https://www.scopelist.com/Burris-Veracity-2-10x42mm-Ballistic-E2-RFP-MAD-System-MOA-Matte-Riflescope-20062.aspx?affid=bads-shopping-primary-2020&msclkid=9813dde810ab1b122e5083210a944e34&utm_source=bing&utm_medium=cpc&utm_campaign=SL%20%7C%20Bing%20%7C%20Primary%20%7C%20US&utm_term=4580702888090994&utm_content=GSAPI%205e68bc5239392 - https://www.scopelist.com/Burris-Veracity-2-10x42mm-Ballistic-E2-RFP-MAD-System-MOA-Matte-Riflescope-20062.aspx?affid=bads-shopping-primary-2020&msclkid=9813dde810ab1b122e5083210a944e34&utm_source=bing&utm_medium=cpc&utm_campaign=SL%20%7C%20Bing%20%7C%20Primary%20%7C%20US&utm_term=4580702888090994&utm_content=GSAPI%205e68bc5239392

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Semper Fi


Posted By: EdSy
Date Posted: June/06/2020 at 09:07
Thanks to everyone who replied.  I'm hoping to find a nice, used Zeiss Conquest MC 3-9x40 with Z-plex for under $450.  I was able to locate a used Leupold VX-3, 3.5-10x50 for well under $400.  It tracks very well, and when I looked at details in the woods in moderate shade, the objects appeared sharp with good detail.  I'll probably like the dim light performance of the Zeiss better, once I find one, but for my deer hunting, the Leupold will probably work fine.  -Ed

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-Ed


Posted By: tejas
Date Posted: June/06/2020 at 10:36
I believe the old Zeiss Conquests were actually manufactured by Meopta. Not sure which Meopta is the equivalent but for sure someone on here knows. Something to keep in mind while your looking, if you can find the Meopta for the same price. I think some Cabela brand scopes are also made by Meopta.


Posted By: supertool73
Date Posted: June/06/2020 at 18:56
the current meopta meopro’s are the same or near same as the old good zeiss conquest. The meopros are a dandy scope

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Posted By: EdSy
Date Posted: June/15/2020 at 18:24
Today I had the opportunity to compare clarity and resolution of a Leupold VX-3, 3.5-10x50 (set at 9x) with a Zeiss Conquest 3-9x40 MC set at 9x.  I observed a sight-in target with 1" grid and the Air Force 1951 1X bar and number card (ink jet print copy off of my computer).  Both target and the AF card were in full shade with the rest of the range in bright sun.  After spending some time focusing both scopes for the sharpest crosshairs/image at 100 yards, I switched back and forth between the two scopes studying the fine grid lines on the sight-in target, and the AF card.  I found the two scopes very close in sharpness of the lines and in brightness of the image.  I will continue to compare the two scopes, under first light / last light conditions.  Thanks to all who have weighed in on my question.  -Ed

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-Ed



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