Re: 4000 Angstroms

From: Andy Resnick (andy.resnick_at_op.case.edu)
Date: 03/17/05 

Date: Thu, 17 Mar 2005 15:56:24 -0500

Darangutan wrote:
> A little light-hearted aside - I heard some song lyrics that touched on
> the range of the human eye, and I was wondering about their scientific
> accuracy. Don't know if anyone has heard "4000 Angstroms" by 'The
> Ohms', but the lyrics basically state:
>
> "4000 angstroms is the wavelength hat god saw fit for us to see"
>
> and
>
> "4000 Angstroms - beyond that is ultra-violet light"
>
> Is 4000 Angstroms really the absolute limit of the human eye? I did a
> little web research and I see varying figures.
>
<snip>

According to the "standard eye", used in photometric calculations, the
visibility factor for the daylight adjusted (photopic, dark adjusted is
scotopic) eye is 0.0004 at 400 nm (it's 1 at 555 nm). Scotopic
visibility is different.

So, the "standard eye" can see a bit bluer than 400 nm, especially if
the source is bright enough. Of course, this being the "standard eye",
YMMV.

I'm not sure where the visibility factor becomes rigorously zero, or if
it even does. But, 4000 Angstroms is a nice round number. 

-- 
Andrew Resnick, Ph.D.
Department of Physiology and Biophysics
Case Western Reserve University

Relevant Pages

  • Re: Where is digital camera resolution going?
    ... just being able to resolve 0.7 line pairs / minute which would be 2.4 ... and corresponds to a normal eye. ... "The Modulation Transfer Function of the Human Eye" English Translation 1969 ... Third in the list above, by Otto Schade is a little earlier but probably more significant, since it is the *first* attempt to *measure* the spatial frequency response of the human eye, as opposed to a less useful contrast limiting figure. ...
    (rec.photo.digital)
  • Re: New glasses causing trapezoidal distortions
    ... I am an engineer -- interested in science and prevention of a negative ... Also, OD is right eye, OS is left eye. ... of the human eye is all about science and medicine. ... Otis just doesn't get it. ...
    (sci.med.vision)
  • Re: Letter to the Editor: Complexity of the human eye
    ... Douglas Bryenldsen recently made his case for Darwinian evolution when ... The human eye actually is an organ of staggering complexity - not ... Darwin answered his "objection" in the same paragraph. ...
    (talk.origins)
  • Re: Letter to the Editor: Complexity of the human eye
    ... Douglas Bryenldsen recently made his case for Darwinian evolution when ... The human eye actually is an organ of staggering complexity - not ... Darwin answered his "objection" in the same paragraph. ...
    (talk.origins)
  • Re: Letter to the Editor: Complexity of the human eye
    ... Douglas Bryenldsen recently made his case for Darwinian evolution when ... The human eye actually is an organ of staggering complexity - not ... Darwin answered his "objection" in the same paragraph. ...
    (talk.origins)
Quantcast