Bino Magnification vs Exit Pupil

[AkMtnRunner]

This thread on BirdForum gets real interesting around post #15. https://www.birdforum.net/showthread.php?t=378445

Then, posts #21 and #22 give some interesting charts.

The take-away that I get is we may be giving too much credence to the brightness and not enough to making a larger picture of what we are trying to distinguish. From my own experience, I know that I can read distant license plates better, even freehand and in twilight, with my 15x than my 10x. Though shakier, I can still discern more detail. Obviously, there's the decreased FOV but that can be worked around to some degree. I think I'll be testing out my 15x a bit more to potentially be my only binos for some trips.

Thoughts?

 

[binoman]

This thread on BirdForum gets real interesting around post #15. https://www.birdforum.net/showthread.php?t=378445

Then, posts #21 and #22 give some interesting charts.

The take-away that I get is we may be giving too much credence to the brightness and not enough to making a larger picture of what we are trying to distinguish. From my own experience, I know that I can read distant license plates better, even freehand and in twilight, with my 15x than my 10x. Though shakier, I can still discern more detail. Obviously, there's the decreased FOV but that can be worked around to some degree. I think I'll be testing out my 15x a bit more to potentially be my only binos for some trips.

Thoughts?

Very interesting charts! The take away I got was larger exit pupils (resulting from larger objective sizes) benefit you more in low light conditions then in daylight where the differences are very small. This is due to the fact the eye will dilate more in darker conditions and will benefit from a larger exit pupil.

 

[AkMtnRunner]

I found it also interesting that in those studies, the point at which the greater exit pupils showed advantage wasn't until basically moonlight, beyond what we (hunters) consider twilight.

 

[Beendare]

Good info...thanks for linking. Those Bird forums are a wealth of info I've been referencing for years....and I find it interesting THEY are using hunting sites for info referencing Rokslide and Ryans review!

Personally, I have seem the small exit pupil work against me in low light....on lower power 8x and 10x binos. I sold a pair of Zeiss 8x30's for just that reason.


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[binoman]

Good info...thanks for linking. Those Bird forums are a wealth of info I've been referencing for years....and I find it interesting THEY are using hunting sites for info referencing Rokslide and Ryans review!

Personally, I have seem the small exit pupil work against me in low light....on lower power 8x and 10x binos. I sold a pair of Zeiss 8x30's for just that reason.


....

I believe it. I was recently comparing my vortex viper 12x50 to a Leupold bx-4 8x32 in twilight and it was very obvious that the smaller 8x32 struggled in low light. Granted the additional magnification if the viper helped. Smaller binoculars are great for saving weight and easier to travel with but they will have limitations in low light conditions.

 

[LostArra]

I believe it. I was recently comparing my vortex viper 12x50 to a Leupold bx-4 8x32 in twilight and it was very obvious that the smaller 8x32 struggled in low light. Granted the additional magnification if the viper helped. Smaller binoculars are great for saving weight and easier to travel with but they will have limitations in low light conditions.

Quality of glass and coatings will affect this too. Maybe more than the magnification and objective numbers.