Re: Ultraviolet Light Pinhole Camera Project

Hi Adam,

I was introduced to pinhole photography by a friend who was doing a PhD on
bee vision. He used pinhole and quartz lensed cameras to record how
different Australian flowers look to bees who have UV sensitive eyes. Some
flowers look really plain in normal light but incredible in UV. There are
some fantastic examples of UV flower images using a quartz lens, as well as
some UV photography links and information about good UV sensitive films and
filters etc, at:

http://www.naturfotograf.com/index2_PC.html

Cheers,
Tim

>From: Adam Leiferman <leifermana@kimball.k12.sd.us>
>Reply-To: pinhole-discussion@pinhole.com
>To: "'pinhole-discussion@pinhole.com'" <pinhole-discussion@pinhole.com>
>Subject: [pinhole-discussion] Ultraviolet Light Pinhole Camera Project
>Date: Sun, 21 Apr 2002 11:49:35 -0500
>
>Hi Pinholers,
>
>During the past few months I have successfully constructed a laser that
>emits a beam of ultraviolet light. I wondered if this short wavelength
>light could be used to make a picture on ordinary photographic film and
>found that easiest way was to use a pinhole camera. (Ordinary camera
>lenses
>are out, since UV light is blocked by glass, and while special "UV lenses"
>are available, they are expensive.) I therefore created a homebrew
>pinhole
>camera and used it to take pictures using UV light. I used the same camera
>to take pictures with light from a red diode laser hoping that I would be
>able to detect a difference in the quality of my pictures.
>
>First I shone the UV laser on a front-surface convex mirror. The light
>reflected off the mirror and spread out over a small model cow. I then made
>"pinhole lenses" specifically constructed to create the best images for the
>wavelength of light that I was using. The pinhole's size was found through
>a formula that is available at the site
>http://www.pinholevisions.org/resources/articles/Young/. I employed black
>and white panchromatic film that I believed was sensitive to my wavelength
>of UV light, even though I could not find a sensitivity chart that extended
>to 337.1 nm, the wavelength of my laser. First I tried 400 ISO speed film,
>but it was not sensitive enough. I then went to the fastest film I could
>find, which was KODAK P3200 TMZ. I was able to make this film work with an
>exposure time of 10 minutes.
>
>The photograph taken with UV light was slightly sharper and clearer than
>the
>photographs taken with red light. The reason is that the small wavelength
>of the UV light causes less image blurring due to diffraction. To be sure
>that the formula I used for the pinhole size was correct, I then made
>pinhole lenses that were slightly smaller and slightly larger than the
>optimal size predicted by theory. I took pictures with each and the results
>agreed with the equations. The smaller-than-optimal pinhole caused the
>photo
>to be slightly diffracted and the larger-than-optimal pinhole caused the
>photo to be a little blurrier due to the increased hole size.
>

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Received on Mon Apr 22 01:42:22 2002