[pure-silver] Re: (sligthly OT) Film flatness in a 4*5 holder

Ok..the last on on this..

Indeed the Wood effect is caused by something else (again
Wiki...;-)..although I have read the same in other publications:

............black-and-white images with a dreamlike or sometimes lurid
appearance known as the "Wood Effect."

The effect is mainly caused by foliage (such as tree leaves and grass)
strongly reflecting in the same way visible light is reflected from
snow. Chlorophyll is transparent at these wavelengths and so does not
block this reflectance. There is a small contribution from chlorophyll
fluorescence, but this is extremely small and is not the real cause of
the brightness seen in infrared photographs. The other attributes of
infrared photographs include very dark skies and penetration of
atmospheric haze, caused by reduced Rayleigh scattering and Mie
scattering (respectively) in the atmosphere compared to visible light.
The dark skies, in turn, result in less infrared light in shadows and
dark reflections of those skies from water, and clouds will stand out
strongly. These wavelengths also penetrate a few millimeters into skin
and give a milky look to portraits, although eyes often look black.....


Best,

Cor

> -----Original Message-----
> From: pure-silver-bounce@xxxxxxxxxxxxx [mailto:pure-silver-
> bounce@xxxxxxxxxxxxx] On Behalf Of Rob C
> Sent: woensdag 4 april 2007 16:41
> To: pure-silver@xxxxxxxxxxxxx
> Subject: [pure-silver] Re: (sligthly OT) Film flatness in a 4*5 holder
> 
> > ..;-)..only chlorophyll is green, chloros is greek for green
(chloros =
> green and phyllon = leaf, long live Wiki..;-)..)
> 
> yeah long live wiki because if you look at its entry more closely it
says
> its absorption over around 700nm is ZERO! (see graph)
> 
> it absorbs mostly red and blue leaving green and non visble (to us)
> wavelengths but it absorbs more green than infra red. If you could see
> infra red you would see what your infra red film sees which is a lot
of
> reflection which is why foliage is very bright on infra red film.
> 
> Infra red paint would look black to us!
> 
> Rob C
> 
>
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