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
Difficult to answer this one (though some will try) because the human brain does so much post processing. Neasurements of eyeball parameters such as resolution or depth of field are largely meaningless; that is, we see much better than eyeball specifications would indicate. For example, no matter what the eyeball's depth of field, we perceive our 'depth of field' to be infinite because that which we attend is always in focus, and the brain fills in the rest to make it seem so. Our 'focal range' changes with age. Young people can see as close as a few centimeters -- older folks may struggle with a meter or more. Our 'film speed' is continuously variable -- a dark adapted eye can detect just a few photons yet we can also operate well on a sunny day at the beach -- this is far more change than can be accommodated by changes in our 'f-stop setting' (iris diameter). Even our 'shutter speeds' can seem extremely short because for the most part we see even fast-moving objects clearly and unblurred thanks to the image processing our brains do. Regards, Gary Nored
