It was good of Gary to resurrect my old question, times have moved on from
then and I have gained a lot of useful information. After all, 'meaningless'
is in the eye of the beholder ! and for the purposes I required, eveything I
have found out is 'meaningful.
For those interested AVERAGE values are:
Cornea to retina 24mm
Lens dia. 9mm
Light sensitive Rods (black and white) 400+ASA
High light sensitivity, low resolution
Cones (colour) 25 ASA
Low light sensitivity, high resolution
Normally sensitive to yellow/green light during the day
blue/green at night.
Acute vision angle 15 deg.
Data from up to 200 deg.
Attentive angle 20-30 deg.
Angle of view 46 deg
Iris dia 2mm bright light, 8mm dim light
Focal length 80 - 120 mm
Distant focus 6m - infinity
Focus range 25 cm - infinity
Persistance of vision (shutter speed?) 0.1 s
From: "Gary Nored"
On 22 Jul 2002, at 11:16, eco...@aol.com wrote:
I know this is not strictly pinhole, but I wondered if
anyone had access to the average human eye values for the camera variables.
ie Respective - film speed, shutter speed, aperture, focus range, depth of
field etc. Thanks
Ellis
This question comes up from time to time in a number of photo-related
groups. The best answer is that it is a meaningless question. The human
visual system does so much "post processing" that what we see, and how well,
bears no resemblance to the optical performance of the eyeball itself. Our
visual experience is essentially wide field (vertically and horizontally),
ultra high-definition, full color, moving, with infinite depth of field in
almost any lighting situation. If you were looking only at the eye's
performance you would get the idea that human vision is characterized by
poor resolution in only a very narrow field, surrounded by terrible
resolution over the wide field.
The depth of field would appear to be poor in all but full sunlight and
there is a blind spot in the picture!
The thing I like most about pinhole photography is that the process prevents
the brain from processing everything into a "realistic" image, which gives
us a whole new visual perspective of the world.
Gary Nored
