I just discovered an interesting article about several different reasons
why certain fabric and flowers record differently on film than the way
we see them.
There seems to be three different phenomena most commonly encountered.
1) UV reflection. This causes colors to appear bluer than they are,
sometime noted with certain fabrics
2) ultraviolet fluorescence: this is when a fabric absorbs UV and
reflects it back as blue. This is sometimes seen in wedding dresses and
other very white materials, and some detergents contain dyes that cause
this "whiter than white" result.
3) As Owen stated, "anomalous reflectance", which is when the near IR
spectrum, which is not very visible to humans, is picked up by the film,
making bluish flowers turn reddish.
The full article can be found at:
For people interested in "bee vision" there are a number of websites
that detail how bees see. They have 5 eyes, some of which "see" light
intensity, but others see the green, blue and UV spectrum. They
apparently can't "see" red. They do seem to use their UV visual
sensitivity to locate pollinating flowers.
Birds also have some UV vision.
So, that's my birds and bees lesson for today ;-)
Art
owenpevans wrote:
> Hi Robert and Paul,
> I specialize in floral photography and the pink cast which occurs is
> called anomalous reflection or the ageratum effect. ( you really see the
> effect when photographing the floss flower [ageratum houstonianum] under
> direct sunlight) Instead of blue, film will record the colour as pink or
> purple. Nevermind the names; the reason that this occurs is because film
> sees colours differently than our eyes do and the film is more sensitive to
> the infrared end of the spectrum.
> To correct for this, you need to mount a mid-blue filter. A deep-blue
> produces too much cast over the whole image and a light-blue filter isn't
> enough for any improvement. If no filters are available, make some shade
> over the flower and the effect goes away since it really requires direct
> light to manifest itself.
> If a digital CCD or sensor mimics film, the effect can happen but this
> is usually an effect of film.
> Hope this is useful.
> Owen
>
> Owen P. Evans
> J.33.3
>
>
>
> ----- Original Message -----
> From: "Robert55" <robert55@xs4all.nl>
> To: <owenpevans@rogers.com>
> Sent: Wednesday, January 29, 2003 2:22 PM
> Subject: [filmscanners] Re: Filmscanners - is this about as good as itgets?
>
>
> Thanks, your explanation seems more logical than mine
> ----- Original Message -----
> From: Paul D. DeRocco <pderocco@ix.netcom.com>
> To: <robert55@xs4all.nl>
> Sent: Wednesday, January 29, 2003 6:52 PM
> Subject: [filmscanners] RE: Filmscanners - is this about as good as itgets?
>
>
>
>>>From: Robert55
>>>
>>>From time to time I find a picture of some very boring pink
>>>flowers, which I
>>>suppose I photographed because they were interesting blue flowers.
>>>
> Someone
>
>>>who has more knowledge of flowers than I have (I don't know whether we
>>>
> are
>
>>>talking about the same flowers) said this was because these flowers
>>>
> absorb
>
>>>(don't reflect) UV light. If I understand this correctly this is
>>>
> somewhat
>
>>>like using an UV-filter to eliminate blue haze in high mountains. It
>>>
> would
>
>>>be interesting to know what effect (if any) a UV-filter has on a digital
>>>camera
>>>
>>I've heard that what upsets the photography of some flowers is that they
>>reflect a lot of infrared, which is picked up as red by some films or
>>sensors. (Bees apparently see this range of color.) That's why the Minolta
>>DiMage 7i camera added an IR filter--I guess some DiMage 7 owners
>>complained.
>>
>>--
>>
>>Ciao, Paul D. DeRocco
>>Paul mailto:pderocco@ix.netcom.com
>>
>>
>
>
>
>
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