flowers in ultra violet

[rollin_verlinde]

I' ve got an assignment this morning to make pictures of flowers in

the way they are seen by insects, more specific bees.

So I want to use ultra-violet light and the kodak EIR film, which is

(more) sensitive for uv than other films. My questions now are : what

(common available) filters to use, how to determine the right

exposure, and for the European collegues : which flowers have an

invisible UV-pattern that could be interesting to picture.

I have only one week, so they must flower now.

All other interesting ideas, tips concerning uv-nature photography are

welcome. Thanks.

 

Rollin

[ryan_taylor1]

Phil Greenspun has a link on the photo.net page that discusses this topic.

[matthew_smith1]

http://www.foto.no/nikon/uvstart.html

 

this answers many, if not all, of your questions.

 

http://www.a1.nl/phomepag/markerink/mainpage.htm

 

has more info. two.

 

Dandelions seem to exhinit good UV characteristics. However, as a botany student, it is my opinion that virtual all bee pollinated flowers without obvious nectar guides (and many with them) are good candidates for UV characteristics.

 

I recomend you start saving- the 105 UV lens costs $4,000! And that doesn't include the SB-140(?).

 

Matt

[rob_s.]

Uh... correct me if I'm wrong, but IR film is sensitive to the INFRARED end of the spectrum, not the ULTRAVIOLET range.

[matthew_smith1]

From the link above:

 

"This film (EIR) has, in common with other IR films, a high and potentially useful sensitivity within the UV range."

 

Maybe EIR is a good choice, if that's what other UV photogs are using.

[rollin_verlinde]

Hi guys,

 

Thanks for the information so far. The reason why EIR is usable for UV is the lack of yellow-filter inside the film. For IR one must use a #12 deep yellow filter in front of the lens to block out blue.

 

Of course, I did some research in the mean-time myself, and found out that especially uniform blue and yellow flowers (never red) have such invisible markings, most obvious in flowers often pollinated by bees.

 

To end with, most slide film is sensitive for UV till 380 nm (but not very much, with that inbuilt yellow filter) , and most glass-lenses, especially older, single coated ones (like enlarger lenses on bellows for example, which I use for this project)transmit UV till 320 nm. The only thing you need is a Wratten #18a or a B+W 403 filter which block all visible light. And that is my problem, they cannot be found here in Belgium in a matter of months, so my project ends here, unless someone can give one to use it for a while ;-).

 

Thanks again,

 

Rollin

[struan_gray]

It's not strictly part of your assignment, but if you can find the

filters, you might want to expand the UV imaging beyond flowers. Many

iridescent objects have interesting UV patterns, including bird

feathers, butterflies and beetles. The diffraction that causes, say,

a red colour on a butterfly wing, also works for light at half the

wavelength, which is in the near UV.

 

Another aspect of UV nature photography is fluorescence and

phosphorescence - both of which can be photographed with normal film

and filters. Phosphorescence is often weak and hard to photograph,

but bio-minerals like coral and sea shells often have quite

interesting and strong flourescence patterns under UV light, which

would be easy enough to photograph in a studio setting. Many

inorganic minerals and crystals also show fluorescence, so if there is

a museum of geology near you it might be worth doing a project on

that.

[dsms photos]

<p>I have worked in that field "a bit" and some results and techniques explained may be found here in my BLOG <a href="http://photographyoftheinvisibleworld.blogspot.com/">http://photographyoftheinvisibleworld.blogspot.com/</a> and here <a href="http://www.pbase.com/kds315/uv_photos">http://www.pbase.com/kds315/uv_photos</a><br>

Cheers, Klaus</p>