Re: PHOTO-3D digest 1655

[P3D Jim Crowell <crowell@xxxxxxxxxxxxxxx>]

At 12:11 PM 10/30/96, photo-3d@xxxxxxxxxxxxxxx wrote:
>Date: Wed, 30 Oct 1996 12:54:23 -0500 (EST)
>From: P3D Dr. George A. Themelis <fj834@xxxxxxxxxxxxxxxxxxxxx>
>To: photo-3d@xxxxxxxxxxxxxxx
>Subject: Re: Finding camera leaks
>Message-ID: <199610301754.MAA29934@xxxxxxxxxxxxxxxxxxx>
>
>>  I don't know for sure, but I think the film test (with 400
>>speed or higher) is a more sensitive test. The bulb in the
>>camera test is fine for bad leaks.
>
>It took a bright halogen and dark-adapted eyes.  Dark adaption is very
>important!  Perhaps Jim C. can tell us how sensitive dark-adapted eyes are.
>It total dark I can see such a low amount of light that a 400 speed film
>could not record, I am sure!
>

Hi all,

I've been back up at Berkeley working my buns off (12-16 hrs/day) for the
last week--what'd I miss?

Very sensitive--claim is that rod photoreceptors respond to single photons.
You need to get a certain number of rods firing within a fairly short
space of time over a small area to drive a retinal ganglion cell.  I don't
remember the required flux density, but it's real small.

-Jim C.

----------------------
Jim Crowell
Division of Biology
216-76
Caltech
Pasadena, CA
(818) 395-8337
jim@xxxxxxxxxxxxxxx



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