Karl....
Great minds think alike.
h
karl shah-jenner <shahjen@xxxxxxxxxxxx> wrote:
karl shah-jenner <shahjen@xxxxxxxxxxxx> wrote:
From: "Bob Blakely" : On the macro scale (above the scale of particle
physics), intensity drops
: off as the square of the distance for all electromagnetic energy,
including
: light, all the time, everywhere in the universe. It's the law. No
: exceptions.
just a quick interjection - this rule applies to a point source light, no
debate whatsoever but unfortunately it doesn't apply when a lens or
collimator of any desription is involved.
as an extreme example to contrast with a point source light is a laser
where the power doesn't drop with the same relationship to distance.
the best relationship to look at when talking about enlarging is the size
of the image on the baseboard - if the image has 4 times the area then any
given section of that area is only receiving 1/4 of the light intensity as
before.. the relationship to height will still be there but it's more
complex than the straight iverse / distance law
karl
Herschel Mair
Head of the Department of Photography,
Head of the Department of Photography,
Higher College of Technology
Muscat
Sultanate of Oman
Muscat
Sultanate of Oman
Adobe Certified instructor
+ (986) 99899 673
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