Re: Ultraviolet Light Pinhole Camera Project

----- Original Message -----
From: "Adam Leiferman" <leifermana@kimball.k12.sd.us>

> First I shone the UV laser on a front-surface convex mirror.....
> 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/.

> 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.

Adam,
            Many thanks for lettings us know of your tests. There is a number
of us interested not only in the aesthetics of pinhole photography but also in
the science behind it. These kind of things are interesting and exciting for us
(for me, anyway).

The article you mentioned above, from which you took the formula for optimum
pinhole size gives a formula and a approximated one, the latter being:
S^2=lambda*F and the former: S^2=0.61*lambda*F. You took images using
smaller-than and larger-than the optimum size, my question is: which formula did
you use to find your optimum size?

Thanks again,

Guillermo
Received on Sun Apr 21 13:25:17 2002