Is there a threshold of lense quality above which eyes can't tell a difference? I see HD glass and scopes that cost over $2k and wonder if the eye can actually see the difference.
Jim
Jim
Rifle Scopes Limit of useful lense quality?
- Thread starter pepperbelly
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Re: Limit of useful lense quality?
Technically, there is no limit to usable image quality. There is no threshold above which more resolution/contrast is useless "because the resolution of the human eye is lower anyway". Resolution/contrast losses of optical systems that are connected in series (like a human eye behind a telescope) are multiplied to get the end result, just like transmission losses, so everything along the way that degrades the image in any way will degrade the end result.
That said, people tend to "adapt" to the highest level of optical quality that they are familiar with and take that level of image qality -with all its flaws- as given. Once you have "reached the next level" so to speak, the shortcomings of lesser optics become apparent.
While we're at it, some comments about "glass". Oftentimes it seems like people assume the quality of an optical system to depend mainly on the "type of glass" being used. This is like saying that "these two scope brands use the same type of aluminum, so their scopes are equally rugged". Make any sense? Neither does the way "glass" seems to be understood by most people here.
Sure, the glass types being used have to be the right ones, but they are just raw materials that are pretty much available to anyone who is willing to pay for them.
What sets one optical design apart from another is the optical calculations, meaning, in simple terms, how the lenses are shaped and positioned relative to each other and thereby how the different optical aberrations are balanced. This requires highly specialized knowledge that seems to be an art form as much as it is a science. You cannot open a drawer, pull out the textbook design for let's say a 3-12x50 scope, specify some funky sounding glass types (the funkier and the more expensive, the better) and create a great optical design. It just doesn't work like that.
Then there are manufacturing tolerances regarding the shape and surface quality of the lenses that have to be held to a certain standard to achieve consistency, and oftentimes glass types that are desirable to use for good image quality will be hard to work with, making the end product more expensive.
There is much, much more that goes into designing a scope with great image quality than choosing "good glass" as raw material.
Technically, there is no limit to usable image quality. There is no threshold above which more resolution/contrast is useless "because the resolution of the human eye is lower anyway". Resolution/contrast losses of optical systems that are connected in series (like a human eye behind a telescope) are multiplied to get the end result, just like transmission losses, so everything along the way that degrades the image in any way will degrade the end result.
That said, people tend to "adapt" to the highest level of optical quality that they are familiar with and take that level of image qality -with all its flaws- as given. Once you have "reached the next level" so to speak, the shortcomings of lesser optics become apparent.
While we're at it, some comments about "glass". Oftentimes it seems like people assume the quality of an optical system to depend mainly on the "type of glass" being used. This is like saying that "these two scope brands use the same type of aluminum, so their scopes are equally rugged". Make any sense? Neither does the way "glass" seems to be understood by most people here.
Sure, the glass types being used have to be the right ones, but they are just raw materials that are pretty much available to anyone who is willing to pay for them.
What sets one optical design apart from another is the optical calculations, meaning, in simple terms, how the lenses are shaped and positioned relative to each other and thereby how the different optical aberrations are balanced. This requires highly specialized knowledge that seems to be an art form as much as it is a science. You cannot open a drawer, pull out the textbook design for let's say a 3-12x50 scope, specify some funky sounding glass types (the funkier and the more expensive, the better) and create a great optical design. It just doesn't work like that.
Then there are manufacturing tolerances regarding the shape and surface quality of the lenses that have to be held to a certain standard to achieve consistency, and oftentimes glass types that are desirable to use for good image quality will be hard to work with, making the end product more expensive.
There is much, much more that goes into designing a scope with great image quality than choosing "good glass" as raw material.
Re: Limit of useful lense quality?
Thanks David. That helps me understand. I didn't know if there was a limit like I remember reading about useful aperture size of the pupil.
Jim
Thanks David. That helps me understand. I didn't know if there was a limit like I remember reading about useful aperture size of the pupil.
Jim
Re: Limit of useful lense quality?
There is indeed a limit regarding the usable size of the exit pupil, but that is a different topic than image quality.
Exit pupil is determined by <span style="font-style: italic">effective objective diamter/magnification</span>. The eye can only take advantage of an exit pupil that is as big is the iris/entrance pupil of the eye. Still, a larger exit pupil has the advantage of requiring less careful eye placement behind the scope, so a larger exit pupil may translate to what people describe as a more "comfortable" view.
What is less known is that the tolerance of the scope regarding axial placement of the eye (meaning minimum and maximum eye relief that the scope will tolerate without shadowing) is also a property of the optical design. If the scope requires very careful eye placement to avoid shadowing, this translates to less perceived "ease of viewing".
While this does not have anything to do with image quality per se, it is another example that it is the design of the optical system that counts and the "glass" is just one small factor that contributes to a good, useful scope.
There is indeed a limit regarding the usable size of the exit pupil, but that is a different topic than image quality.
Exit pupil is determined by <span style="font-style: italic">effective objective diamter/magnification</span>. The eye can only take advantage of an exit pupil that is as big is the iris/entrance pupil of the eye. Still, a larger exit pupil has the advantage of requiring less careful eye placement behind the scope, so a larger exit pupil may translate to what people describe as a more "comfortable" view.
What is less known is that the tolerance of the scope regarding axial placement of the eye (meaning minimum and maximum eye relief that the scope will tolerate without shadowing) is also a property of the optical design. If the scope requires very careful eye placement to avoid shadowing, this translates to less perceived "ease of viewing".
While this does not have anything to do with image quality per se, it is another example that it is the design of the optical system that counts and the "glass" is just one small factor that contributes to a good, useful scope.
Re: Limit of useful lense quality?
As with everything else in life, the law of diminishing returns applies. As you get into higher and higher priced scopes, there become less and less difference in the glass/optical quality. That law also implies that you will pay ever larger amounts for tiny improvements at the high end. I think Leupold, Nightforce, Nikon and others make superb glass at the $1k to $1500 range and you are hitting rapidly diminishing returns above $1500.
Another thing to consider is rifle scopes have relatively small objectives compared to spotting scopes: making it that much more difficult to see noticeable differences in glass.
Even if you notice a difference in glass/image, that does not mean it will make one iota of difference in your ability to hit the target.
I think experienced shooters place more of a premium on overall reliability and repeatability of turrets at the high end, recognizing the great image quality is a given with just about any make above $1k. NF gets my "best value" award.
As with everything else in life, the law of diminishing returns applies. As you get into higher and higher priced scopes, there become less and less difference in the glass/optical quality. That law also implies that you will pay ever larger amounts for tiny improvements at the high end. I think Leupold, Nightforce, Nikon and others make superb glass at the $1k to $1500 range and you are hitting rapidly diminishing returns above $1500.
Another thing to consider is rifle scopes have relatively small objectives compared to spotting scopes: making it that much more difficult to see noticeable differences in glass.
Even if you notice a difference in glass/image, that does not mean it will make one iota of difference in your ability to hit the target.
I think experienced shooters place more of a premium on overall reliability and repeatability of turrets at the high end, recognizing the great image quality is a given with just about any make above $1k. NF gets my "best value" award.
Re: Limit of useful lense quality?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scooter-PIE</div><div class="ubbcode-body">
I think experienced shooters place more of a premium on overall reliability and repeatability of turrets at the high end, recognizing the great image quality is a given with just about any make above $1k. NF gets my "best value" award. </div></div>
Even 100-300$ scopes are repeatable and reliable nowadays with all the glass you need to hit a target and someone might say exactly the same for Nikon or Viper PST as you've said for all higher end scopes.
But on topic of lens design i have a question with eye box so basicly (if i understand correctly) the bigger the exit pupil the more comfortable the eyebox. However the down side would be then parallax error which is potentially bigger as you can place your eye further from central axis of the scope. Also exit pupil will be "fixed max" to obj diameter and magnification -> for a 56obj and given magnification (high tens or twenties as lower mags will obviously have huge possible exit pupil) there will be a maximum possible exit pupil size and with it also "maximum comfort-ability" of a scope and also the higher the magnification the closer must an eye be (eye relief)to have reasonable exit pupil (a cone in effect going from last lens (okular) to certain point from last lens where it becomes 0 or picture totally invisible)?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scooter-PIE</div><div class="ubbcode-body">
I think experienced shooters place more of a premium on overall reliability and repeatability of turrets at the high end, recognizing the great image quality is a given with just about any make above $1k. NF gets my "best value" award. </div></div>
Even 100-300$ scopes are repeatable and reliable nowadays with all the glass you need to hit a target and someone might say exactly the same for Nikon or Viper PST as you've said for all higher end scopes.
But on topic of lens design i have a question with eye box so basicly (if i understand correctly) the bigger the exit pupil the more comfortable the eyebox. However the down side would be then parallax error which is potentially bigger as you can place your eye further from central axis of the scope. Also exit pupil will be "fixed max" to obj diameter and magnification -> for a 56obj and given magnification (high tens or twenties as lower mags will obviously have huge possible exit pupil) there will be a maximum possible exit pupil size and with it also "maximum comfort-ability" of a scope and also the higher the magnification the closer must an eye be (eye relief)to have reasonable exit pupil (a cone in effect going from last lens (okular) to certain point from last lens where it becomes 0 or picture totally invisible)?
Re: Limit of useful lense quality?
Exit pupil is simple math: obj / magnification. You want an exit pupil at least as large as the iris diameter under whatever lighting conditions you are shooting. Young shooters can have up to a 7mm iris diameter in low light. For a 40MM objective, a 7x magnification would match that iris in low light. During daytime, you want a minimum 2mm exit pupil. So, for the same 40mm OBJ, that equates to a 20x maximum magnification. Yes, allowing a bigger exit pupil allows more head movement which can introduce parallax error. So, I guess that is a benefit to a smaller exit pupil.
Exit pupil is simple math: obj / magnification. You want an exit pupil at least as large as the iris diameter under whatever lighting conditions you are shooting. Young shooters can have up to a 7mm iris diameter in low light. For a 40MM objective, a 7x magnification would match that iris in low light. During daytime, you want a minimum 2mm exit pupil. So, for the same 40mm OBJ, that equates to a 20x maximum magnification. Yes, allowing a bigger exit pupil allows more head movement which can introduce parallax error. So, I guess that is a benefit to a smaller exit pupil.
Re: Limit of useful lense quality?
I have an S&B PMII, and I love the higher-quality glass and can tell a noticeable difference. At noon on a bright and sunny day, you aren't going to see as much as a difference but in early morning or dusk hours (or just on a cloudy day) the greater light transmission and clarity are extremely apparent.
Is it worth the additional $$$? To me, absolutely. You'll have to make your own decision.
I have an S&B PMII, and I love the higher-quality glass and can tell a noticeable difference. At noon on a bright and sunny day, you aren't going to see as much as a difference but in early morning or dusk hours (or just on a cloudy day) the greater light transmission and clarity are extremely apparent.
Is it worth the additional $$$? To me, absolutely. You'll have to make your own decision.
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