I have put together a JavaScript calculator for determining light intensity
using your SLR's built-in meter.

http://www.firstrays.com/measurelight.htm

Comments, please?

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!

.. . . . . . . . . . .

"Ray" schrieb im Newsbeitrag
...
I have put together a JavaScript calculator for determining light
intensity
using your SLR's built-in meter.

http://www.firstrays.com/measurelight.htm

Comments, please?

My comment is that I now truly believe that you *are* at home sick! ;-)

Looks great, another handy piece of info for us all!
--
Reka

I don't give a damn for a man that can only spell a word one way.
Mark Twain (1835 - 1910)
http://www.rolbox.it/hukari/index.html



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Ray wrote:
I have put together a JavaScript calculator for determining light intensity
using your SLR's built-in meter.

http://www.firstrays.com/measurelight.htm

Comments, please?


Well, that's about the handiest thing I've ever seen on that subject!

I tried to use my camera to measure my light intensity many years ago. I
gave it up as useless. The reason being that one f stop change or one
exposure setting change doubled the foot candle reading.
For example, suppose you are using f/11. Pointing at the paper gives an
exposure of 1/500 but a little movement changes it to 1/250. So it's
either 2048 foot candles or it's 4096 foot candles. That's a big
difference. Which one is closer to the truth? I have no idea.
Maybe it's my camera. Mine has little LED lights in the viewer so it's
one or the other. I once used an older camera that had a moving needle.
Maybe one like that would point somewhere in between 1/250 and 1/500 and
give a better idea of the true reading?

Steve

In looking at the source code IMHO you need more meta tags so search engines
can find this page.

K Barrett

"Ray" wrote in message
...
I have put together a JavaScript calculator for determining light
intensity
using your SLR's built-in meter.

http://www.firstrays.com/measurelight.htm

Comments, please?

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!

. . . . . . . . . . .

Steve,

If it changes that much, I'd guess that a couple of things might be
happening:

1. You're changing the percentage of the total field of vision that's on
the white paper. Try to get all of it.
2. You're changing the angle of the lens to the paper surface, with 90°
being the best.

In any case, I'd go more with the higher reading, as that one probably had
the better of the two conditions I mentioned, and while it's easy to fool
the meter into receiving less light than is actually present, you can't read
MORE than there is!

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!

.. . . . . . . . . . .
"Steve" wrote in message
t...


Ray wrote:
I have put together a JavaScript calculator for determining light
intensity
using your SLR's built-in meter.

http://www.firstrays.com/measurelight.htm

Comments, please?


Well, that's about the handiest thing I've ever seen on that subject!

I tried to use my camera to measure my light intensity many years ago. I
gave it up as useless. The reason being that one f stop change or one
exposure setting change doubled the foot candle reading.
For example, suppose you are using f/11. Pointing at the paper gives an
exposure of 1/500 but a little movement changes it to 1/250. So it's
either 2048 foot candles or it's 4096 foot candles. That's a big
difference. Which one is closer to the truth? I have no idea.
Maybe it's my camera. Mine has little LED lights in the viewer so it's
one or the other. I once used an older camera that had a moving needle.
Maybe one like that would point somewhere in between 1/250 and 1/500 and
give a better idea of the true reading?

Steve

It's not that it changes that much, it's just that my camera has no
middle ground. The indicator light for (for example) 1/125 comes on and
nothing happens as things get brighter until it changes to 1/250, which
instantly doubles the foot candle reading. Sometimes it would waver
between the 2 reading leaving me wondering.
Don't get me wrong. That calculator of yours is a wonderful idea. I
should get out my camera and play with it again. I haven't used it in so
long, I doubt the batteries that run the meter are still good. Maybe I
should still get it out, if only to remove the dead batteries.

Steve


Ray wrote:

Steve,

If it changes that much, I'd guess that a couple of things might be
happening:

1. You're changing the percentage of the total field of vision that's on
the white paper. Try to get all of it.
2. You're changing the angle of the lens to the paper surface, with 90°
being the best.

In any case, I'd go more with the higher reading, as that one probably had
the better of the two conditions I mentioned, and while it's easy to fool
the meter into receiving less light than is actually present, you can't read
MORE than there is!