Age related usage of "exit pupil 5.25mm" (1 Viewer)

[spiralcoil]

What would you think of binoculars with around 5mm exit pupil (e.g 8x42)? An sport optic store owner saying that people over around 50~65 yrs age could use 8x32 rather than 8x42, because the eye's pupil would not be able to make use of a 5.25mm exit pupil...

What do you think? Is it really that way for most people at that age group, or mostly would still have 5mm or larger pupil opening at darkness? Other words do you rather to have the 8x42 or the 8x32? Do you see the difference in brightness with the 8x42 vs 8x32 if you are that bracket?

 

[Chosun Juan]

It's a good question, and has probably been covered at length on BF before. I recall Ed coming up with some statistical data that blew the conventional wisdom out the window. Those in their 60s and 70s well being able to make use of 5mm+ EPs.

I find that my pupils go beyond 4mm even in daylight, for example when clouds come over, peering under riverbanks, or into hollows etc. A larger EP also makes for an easier view when fatiguing, or during offhand snap viewing too.

One seldom discussed trade-off of the larger EP for older folks in low light, is that the acuity drops in low light, and a wider pupil diameter can also introduce many more eye aberrations into the view.

I like the extra light as the sun sets, but depending on the physiology of your eyes you may be better off with a smaller EP, a dimmer picture, but perhaps use more magnification in the same form factor bin to give a better view.




Chosun 👧

 

[jring]

Hi,

agreed, your maximum pupil size will go down with age from the 7mm (or even a bit above) in your teens, but below 5mm @50 years is not the norm. So maybe sell your 7x50 and get an 8x42 ;-)

Also exit pupil size is not only about best night performance but also easy eye placement at daylight (when your eye's pupil is in the 2.5 to 4 mm area), and a slightly larger exit pupil leaves room for some errors and will still work nicely even when you got the bins to your face quickly because somebody called out a rarity flying past...

8x32 are a nice compromise between full size and pocket and thus do have their following - me included.

Joachim

 

[jan van daalen]

What is often forgotten is the fact that the humans pupil pops up in different directions several times per second. If it wouldn't the brain would "freeze" the image. This means that a 50/65 lens is always brighter compared to a 42 lens because of the fact the pupil gathers more light even if it's only 4 or 5 mm in diameter.

Jan

 

[casscade]

All I know is the view is easier through larger exits imo, I’ve been using 50’s/56’s for a long time, usually in 10x, as to 7 and 8x its usually a 42mm, occasionally a 50/56. In daytime use some of the smaller 10’s such as 32 or 42 may be as sharp as 50’s but it’s just a different view imo.

The larger exits have imo, an easier, more natural/relaxing view with less pressure. Things seem easier to see faster, more like the naked eye, the view is cleaner so to speak. So imo, quality being equal, I feel like larger exit pupils trump smaller ones regardless of age.

 

[rpg51]

I think the fact that you can more quickly and easily place your eyes in the sweet spot is a very big deal.

 

[gwlee]

Despite being in my 70s, I still find binoculars with 7mm exit pupils a little brighter as well as more comfortable to look through than those with 5mm exit pupils. For me, 4mm exit pupils are are a little fiddly and uncomfortable to look through. The only way to really know what will work for you is try them yourself.

 

[jan van daalen]

Last saturday I had a grumpy old man of 92 in the shop who tried them ALL and ended up with the Swarovski Habicht GA7x42.
It is really a matter of try before you buy for each individual.

Jan

 

[Stevenkelby]

I agree with the old man, Jan!

Habicht GA 7x42 takes the first place prize for my favourite binocular in terms of viewing ease and comfort, brightness, centre clarity, durability and more!