ImBIllT
Silver $$ Contributor
I still don’t have a PM. Perhaps you should go get one of your variables and zoom into to see if you ever clicked “send”.
2-7x32 and 3-9x40 scopes. Not what they use to be. Ha ha ha.
- Thread starter NDAR15MAN
- Start date
Well, ya didn't add a reply "quote" from this thread, so who were you typing to?
Must be someone on "ignore", cuz I only saw your words. & may have taken them out of context.
The "brightness" you see comes from not only the objective diameter, but also the amount of light your eye can actually use via the ocular. For the most part, the brightness we see is due to lens quality and the type and quality of the coatings on the elements. And then we have what each individual sees through his/her eyes. With my new Abbott Medical Optics Intraocular lens, everything I look at is even brighter than before. My fixed power scopes are also lighter in weight than most variables, and have fewer internal components to go haywire.
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Apologies...
Never any harm in disagreeing!
ImBIllT
Silver $$ Contributor
Now THAT I agree with! Open disagreement is the only way we will ever understand all sides of an argument, and that greater awareness increases our enlightenment whether it confirms our former position or leads us to a knew one.
The simple physics of the brightness issue are this- if the lenses are equal, then the scope with fewer lenses will be brighter. There are fixed power scopes out there with lenses just as good as the best variables. If you are not comparing scopes of equal lens quality, then the differences are not related to being fixed power or variable power, but rather the difference in the lenses and coatings themselves. Today’s scopes are good enough that the difference is not nearly as dramatic as in the past, but the difference exists, and is significant for some people under some circumstances.
Brightness is by no means the only, or even the most important factor in choosing a scope, but if you need more brightness, reducing the number of lenses is still the best path there, in fact it is even more significant today because the majority of manufacturers have very bright lenses and he difference between the brightest and the average is much closer. Still, there is more to “brightness” than light transmission, more to usefulness in dim light than “brightness” and more to how a particular shooter chooses a scope for a particular situation than just its low light performance.
Goes again back to exit pupil & useability...
Ok, let's assume equal type quality glass.
A fixed 6x42 scope has a 7mm exit pupil (on 6x)
A 2-10x50 has an exit pupil of ~7mm at roughly 7x magnification.
So, not only does the variable (with larger objective) allow for more magnification at the same exit pupil, the quality of glass nowadays is such, that you very likely would NOT be able to tell which one was "brighter"...
And, if the variable scope DID happen to begin looking 'dim' as light really fades, the shooter could simply dial down the mag setting, thereby INCREASING the exit pupil. Hence, allowing a more "bright" appearance of the sight picture...
Is that possible with a fixed power scope?
Nope, you're stuck on whatever it's set at. There's no way to dial out for a larger sight picture, or to eek out a teeny bit more 'brightness' when dark-thirty arrives...
So, as always...choose wisely! And, to say, yet again...
nowadays a quality variable gives up NOTHING in real world "brightness", vs. a fixed power scope. Welcome out of the 1980s...
Ok, let's assume equal type quality glass.
A fixed 6x42 scope has a 7mm exit pupil (on 6x)
A 2-10x50 has an exit pupil of ~7mm at roughly 7x magnification.
So, not only does the variable (with larger objective) allow for more magnification at the same exit pupil, the quality of glass nowadays is such, that you very likely would NOT be able to tell which one was "brighter"...
And, if the variable scope DID happen to begin looking 'dim' as light really fades, the shooter could simply dial down the mag setting, thereby INCREASING the exit pupil. Hence, allowing a more "bright" appearance of the sight picture...
Is that possible with a fixed power scope?
Nope, you're stuck on whatever it's set at. There's no way to dial out for a larger sight picture, or to eek out a teeny bit more 'brightness' when dark-thirty arrives...
So, as always...choose wisely! And, to say, yet again...
nowadays a quality variable gives up NOTHING in real world "brightness", vs. a fixed power scope. Welcome out of the 1980s...
Guys thanks for the help. Did not want to start a argument here. Just saying at 59 and bad eye sight the 2-7 Leupold and my 3-9 Nikon shotgun and muzzleloader scopes just not cutting it for me. Detached Retina 1 1/2 years ago don’t help but Dr got me back were I can see ok. Cross hairs , magnification just don’t jump out at me like I was 30. I think we’re all going to get there sometime in our life. I think I am going to put a Nikon Monarch 3 5-20x44 BDC on shotgun this week and shoot it and see if I like it. It has a good eye relif and it is on a gun I don’t shoot that much anymore. Will not cost me anything to give it a try. I think the 5x power will work in the woods real good or in stand in woods. the 20x power will let me get a good bead on the shoulder at 150 yards in picked bean field. Once agian learned a lot from all you guys. Thanks. Marty
As you age, your pupils lose their ability to dilate, fully.
Same as losing flexibility in your joints/extremities, it's an unfortunate inevitability...
Still, strive for as large an exit pupil value from a scope, as you can. If only to insure that your pupils are getting as much 'light' as they can allow!
Same as losing flexibility in your joints/extremities, it's an unfortunate inevitability...
Still, strive for as large an exit pupil value from a scope, as you can. If only to insure that your pupils are getting as much 'light' as they can allow!
I don't believe this is true, sir. Of course now you are going to argue with me, but here goes... The exit pupil, as I understand it, is important because if it matches in size your pupil in your eye then you will see the most light you can. There are probably more ways to word it and you will argue about that too, but bear with me a second....when the exit pupil is smaller than your pupil diameter then you see less light. This is why the highest power doesn't necessarily appear the brightest in low light. If the exit pupil is larger, as you suggest it floods your eye with too much and your eye will dilate down smaller...and again you will see less because your "night vision" dilation is lost.
As to the fixed vs. variable...some of what you say is true, to a degree, but lets look at it another way. As posted previously, each lens reduces the amount of light getting to your eye. Again, fifty more ways to say that and all will invoke more arguing. In it's simplest form, and even you have to agree, no lens can allow all the available light thru. Period, end of story, and this is cut in stone.
So, lets take a variable, in this case any variable, because we are only going to work with one scope...this one. In theory, if we could remove only the lenses that are required to make it a variable, put it back together with all the same lenses except those NOT needed for it to zoom what you would see as a "fixed power" scope will also appear brighter, period, end of story...this is also cut in stone, because no lens made can allow all the light thru. A lens in a scope is like a restriction in a water pipe...take out some of the restrictions and more water has to come thru. Now, as soon as you start throwing in differences, brands, and coatings you are now talking apples and oranges and the whole argument is "unsolvable".
What I find amusing is that the military, for many years, always used fixed power scopes for sniping. The reasoning was that the zoom feature could eventually wear out and cause the scope to be unable to maintain "zero".
Maybe, but they are shooting at a man sized target...never seen one loose that much ability to hold some kind of zero...but the real clincher is that they don't keep them long enough to wear anything out anyway, so why worry...we will buy them a new one long before what they have is ever worn!!!!
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Nope, we actually do agree.
What anyone's eyes are "allowed" to see, is limited by two things:
1. your own max.pupil diameter (which becomes limited with age)
2. The exit pupil of the scope (which is limited by dialing up magnification)
Whichever one of those values is smaller, is the 'limiting factor'. So, we do agree. The sentence of mine you quoted above suggested to "strive for as large an exit pupil value from the scope as you can"
Translation: keep the exit pupil value of the scope LARGER than the max. Pupil diameter that your eye will allow!
I.e., if your eye can only open to 5mm, then be sure to to maintain the scopes exit pupil value of at least that much. That will "insure your pupil is getting as much light as they can allow".
As to the variable scope argument, you guys are getting wrapped around the arguing the mechanics of a scope's brightness while I'm arguing if tangible 'brightness' is worth being limited to a fixed power...
I HAVE NOT disagreed that a fixed scope can be inherently 'brighter' than a variable. We all already KNOW that, it does not require explaining!
My point is that, for all intents & purposes, a variable scope can & will allow enough 'brightness' that YOUR EYE ITSELF becomes the 'limiting factor' to how 'bright' the scopes image appears!
So, since Ive just again maintained that PLENTY of variable scopes can, and will allow MORE 'brightness' than your own eye can handle, that further solidifies my opinion. Which, again is, a quality variable will be every bit as useably bright as a fixed power, in the field...
Since our eye is the 'limiting factor' in the equation, the neglibly more efficient transmission of a fixed power is inconsequential.
Apply your own logic from your statement, above. Ask yourself:
how can ANY ONE scope "appear brighter" if both are transmitting MORE light than one's own pupil is limited to 'allow'???
Answer: If pupil is limiting factor, BOTH SCOPES will appear equally 'bright'...
Agree, or disagree?
What anyone's eyes are "allowed" to see, is limited by two things:
1. your own max.pupil diameter (which becomes limited with age)
2. The exit pupil of the scope (which is limited by dialing up magnification)
Whichever one of those values is smaller, is the 'limiting factor'. So, we do agree. The sentence of mine you quoted above suggested to "strive for as large an exit pupil value from the scope as you can"
Translation: keep the exit pupil value of the scope LARGER than the max. Pupil diameter that your eye will allow!
I.e., if your eye can only open to 5mm, then be sure to to maintain the scopes exit pupil value of at least that much. That will "insure your pupil is getting as much light as they can allow".
As to the variable scope argument, you guys are getting wrapped around the arguing the mechanics of a scope's brightness while I'm arguing if tangible 'brightness' is worth being limited to a fixed power...
I HAVE NOT disagreed that a fixed scope can be inherently 'brighter' than a variable. We all already KNOW that, it does not require explaining!
My point is that, for all intents & purposes, a variable scope can & will allow enough 'brightness' that YOUR EYE ITSELF becomes the 'limiting factor' to how 'bright' the scopes image appears!
So, since Ive just again maintained that PLENTY of variable scopes can, and will allow MORE 'brightness' than your own eye can handle, that further solidifies my opinion. Which, again is, a quality variable will be every bit as useably bright as a fixed power, in the field...
Since our eye is the 'limiting factor' in the equation, the neglibly more efficient transmission of a fixed power is inconsequential.
Apply your own logic from your statement, above. Ask yourself:
how can ANY ONE scope "appear brighter" if both are transmitting MORE light than one's own pupil is limited to 'allow'???
Answer: If pupil is limiting factor, BOTH SCOPES will appear equally 'bright'...
Agree, or disagree?
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Yep, I understand what you are saying. I have to admit, inasmuch as I like fixed scopes, the best low light performance scopes I own are in fact variables. Scope discussions always generate mixed responses and it appears this is due to the language being used more so than the understanding or lack of it. There was a time on this forum when if someone posted just the words "light gathering" they were jumped on by several resident optics experts with both feet. Optics are hard to understand no matter who is doing the talking. My grandfather was the real expert, followed by my dad. Either one of them could explain things in an easy to understand way.
Not always...
Exit pupil of a scope is derived from simple division math. We already covered that...
Human eye exit pupil average is 5-7mm, subject to individual. Covered that, too..
Soooo,
If a scope allows 7mm of 'light' to pass, but the human pupil only allows 5mm, then that is what limits how 'bright' the scope image appears...
Therefore, arguing the intricacies of scope mechanics, and how light is refractied/absorbed, or otherwise 'lost', due to passing thru extra lens(es), doesn't matter.
What matters is simply this:
"Can a particluar scope allow at least the same exit pupil than the human eye can handle?
If the answer is "YES", then the part about a scope being 'fixed' or 'variable', don't mean chit...
Not always...
Exit pupil of a scope is derived from simple division math. We already covered that...
Human eye exit pupil average is 5-7mm, subject to individual. Covered that, too..
Soooo,
If a scope allows 7mm of 'light' to pass, but the human pupil only allows 5mm, then that is what limits how 'bright' the scope image appears...
Therefore, arguing the intricacies of scope mechanics, and how light is refractied/absorbed, or otherwise 'lost', due to passing thru extra lens(es), doesn't matter.
What matters is simply this:
"Can a particluar scope allow at least the same exit pupil than the human eye can handle?
If the answer is "YES", then the part about a scope being 'fixed' or 'variable', don't mean chit...
If it were only really that easy......you write the above as if exit pupils match or lack of to a given persons eye is about all there is to it. I get what you are saying and I agree...at least in part.
You are leaving out the part about what you are really paying for in a high end scope. Glass quality, lens grind and polish and coatings cannot be dismissed. Now, you like to argue and I am really seriously done, so before you jump back raging about the "exit pupil not right the rest is dead"...again, I get it. I totally understand and agree.
Don't get me wrong, I believe this post has been very productive and I am hopeful that some one some where learned a little something. Two days ago I had some professional jerk ass tell me that as long as you claim to win a shooting match.........it's okay to post bad info regarding reloading.
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