Rathaus
Well-known member
The widest Porro binocular I own has a 96 deg. apparent field
Nice. Which Porro is it?
The widest Porro binocular I own has a 96 deg. apparent field
Thanks for the input. I've got plenty to learn. Are you saying that a larger apparent field of view projects an image on a larger area of the retina? Perhaps that is self-evident to many, but I just want to make sure I understand.
Bill
Nice. Which Porro is it?
Linet Imperial made by Hiiyoshi Kogaku (c. 1 980). Quite a beautiful binocular.
Ed
In normal light, 3% more light reaching the eye should result in the pupils shrinking slightly, so one should never notice that the image is brighter.This example is as ridiculous as you claiming you can see a 1-3% difference in light transmission.
wdc;3629718 For example said:Hi Bill
Work out the area of the circle of view of each of these binos using the pi multiplied by radius squared, the radius being half of your linear fov measurement. Divide the smallest into the biggest to work out how many percents bigger the biggest fov is. Lets say its 20% bigger. It will be 20% bigger at every distance from the observer so it will be 20% bigger at 10 feet and 20% bigger at half a mile. And what can look like a modest number of feet difference can be very significant when calculated as an area of the circle of view.
However you cut it this means a 20% better chance of getting your binos on that warbler flying between trees to catch flies then hiding behind leaves or a 20% better chance of getting your binos on a dragonfly hunting next to a pond and changing direction so fast and so frequently that it makes your eyes hurt.
Lee
As a happy amateur, I don't pretend to understand the physics of some of these posts but, as with art, I know what I like. Having spent years with a Kowa 8.5x44 (fov 122m at 1000m), I have changed to a Nikon (fov 145m at 1000m), and am convinced it is less of a strain on the eyes during prolonged searching, makes it easier to follow birds through foliage, and FOR ME makes birding more pleasurable. Light transmission? I'll leave the experts to debate.
Linet Imperial made by Hiyoshi Kogaku (c. 1980). Quite a beautiful binocular.
Ed
i would really like to have a look through those - I'll admit your description tempted me to run a couple of ebay searches (to no result, perhaps fortunately). There are few things more enjoyable in using binoculars than looking through a pair with a really wide yet well corrected view, and drinking in that wide swath of landscape. Are those Hiyoshi binoculars single coated or multi-coated, and how do you find their image in terms of distortion, aberration etc? Holger Merlitz in his educative discussion of wide angle binoculars believes that the eyepieces of the day were "overstretched when applied to angles beyond 70 degs".
Best regards
patudo
Zeiss HT is the absolute benchmark (at the moment, until someone does better) for light transmission among modern roof prism binos and if you are often viewing during the 1st half hour or last half hour of light in the day then you would struggle to better it with another roof prism bino. Of course there are many other aspects of importance to a bino's performance but we are discussing light transmission here. Personally I wouldn't put extreme light transmission such as the HT's as the most important priority, but HT has a very nice transparancy of view and handles really well too.
Lee
Hi Maljunulo, post 36.
A difference of 0.1 magnitude is 10% (9.65%).