[ATM] Exit pupil and brightness

[George Nikolidakis]

>To detail on this:
>Like the scope aperture stop, the eye pupil cuts off parallel rays, which 
>contain only intensity as a function of angle, not loacation. The location 
>will only substantiate in teh image plane, i.e. the retina. Therefore you 
>would loose the edge of the field if you have a bad retina, the smaller 
>pupil only affects intesity independent of the angle the light enters you 
>eye.
>.. Arjan

Thanks
You got me to realize this simple approach :
The eye is in fact an integrated optical system, and as in all optical
systems,
the brightness of the object is proportional to the size of the objective
lens,
thus reducing the size of the lens will simply reduce the brightness 
of every object within the visual field.

George Nikolidakis
http://geonik.homeip.net


-----Original Message-----
From: Arjan te Marvelde [mailto:Arjan.te.Marvelde at hetnet.nl] 
Sent: Sunday, March 02, 2008 9:27 AM
To: atm at atmlist.net
Cc: al at sgi.com; geoniko at otenet.gr
Subject: Re: [ATM] Exit pupil and brightness
>> But what view is finally right ?
>>
>
> Theirs. *All* the parallel ray bundles for all of the objects
> in the field pass through the exit pupil, and all are vignetted
> by the eye's pupil. Losing the edge is when you have an
> aperture stop in a focal system (i.e. somewhere before the eyepiece,
> not one at the exit pupil of an afocal one.