Translate:
>> The "light source" just gets smaller with distance. Hence there is less light
>> reaching the lens, but the "intensity from the light source" is the same,
>> just
>> that its size in the frame is smaller.
If you replace "intensity from the light source" with "intensity of the light
source"
then it would be correct. A light source radiates out and the intensity per
area it illuminates decreases. But the light source is the same illumination,
if that is what one is photographing, hence the exposure for the light source
itself
does not depend on distance, unless it is foggy or hazy or dark matter
between you and the source. It matters not whether it is a point or a
surface when it is the subject rather than the source of light. Shape only
effect what it will illuminate.
At 12:32 PM 1/4/2009, you wrote:
>Sorry, but I still don't understand. If, in your first sentence, I
>replace "subject" with "light source" and "illumination of the subject"
>with "intensity from the light source" I have replaced subject with
>light source and the statement remains true.
>
>I'm still missing something very fundamental.
>
>Chuck Norcutt
>
>WayneS wrote:
>> At 11:41 AM 1/4/2009, Chuck wrote:
>>> <snip> What I don't
>>> understand is why, once the light has struck and reflected off the
>>> subject, why the subject is not treated as the "light source" for the
>>> reflected light that's emanating from it in the same sense as the sun is
>>> a light source.
>>
>> The subject just gets smaller with distance. Hence there is less light
>> reaching the lens, but the illumination of the subject is the same, just
>> that its size in the frame is smaller.
>>
>> If it is the only subject, then an average meter would vary, but a spot
>> meter on the subject would be constant with distance.
>>
>> WayneS
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