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Al,

Here is a graph for corn. It shows the percentage of apparent reflectance (Ra) caused by steady-state chlorophyll fluorescence (Fs) for the top of a corn leaf. The red line is an unhealthy...

"Regarding the frequency shift, or flourescing, I would believe that this would have a band width that is wider than a single wavelength. Is 673nm the peak radiation, or is it the upper limit to the...

Brian,

"BTW, are you sure that EI400 is overexposure for HIE?"

I was basing my comment about 'plentiful exposure' (I didn't write 'overexposure') on the image, not on the numbers. Even knowing...

Brian,

That 'luminance inside' looks like halation combined with plentiful exposure.

Best,
Helen

http://gallery.photo.net/photo/5132527-md.jpg

Al,

Chlorophyll does fluoresce, but at 673 nm (deep red) rather than in the infrared. In most cases the fluorescence is very weak in comparison to the simple reflection of IR from foliage -...

Brian,

That's also what puzzled me. Almost all the IR photography that we do with film is of reflected infrared radiation, so I haven't managed to grasp what you are saying. (Of course infrared is...

The B+W graphs are in the pdf version of the full handbook and of just the technical section of the handbook on their website: http://www.schneideroptics.com/info/handbook/

If the Lee 87 has the...

Lee make polyester 87 camera filters in both 3x3 and 4x4. B&H have them in stock for $14 and $24 respectively. Wratten 87 gelatin filters are $58 and $90 for the same sizes.

Best,
Helen