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You can crudely use leaves to make starch prints.

A botany lab exercise uses a black and white photographic negative and
an attached leaf to make a starch print. The leaf should have been in
the dark for 24 hours so it contains no starch. The negative is
fastened to the upper leaf surface and the leaf exposed to light from
that side for several hours. The leaf is then detached, cleared of
chlorophyll by boiling in alcohol and the print developed by applying
an iodine solution to the leaf. The iodine turns the starch black.

Experiments in Plant Physiology by Carol Reiss gives detailed
instructions.

This site also gives instructions:
http://www.northern.edu/ramsayj/Bota...bonfixlab.html

David Hershey





(Mike Lyle) wrote in message . com...
(Beverly Erlebacher) wrote in message ...
In article ,
Mike Lyle wrote:
(David Hershey) wrote in message . com...
You are correct that plant chloroplasts are able to move in the leaf
cells depending on the light level.[...etc...]

OK, you've answered the intelligent question. Now, how about a naive
one? I've sometimes wondered if the reactions involved in green
vegetation's sensitivity to light could have been exploited to form
the basis of a photographic process not dependent on silver compounds.

Well, you can put a stencil on an apple and when it ripens, the part that
was covered will not have turned red. This has been recommended to delight
little kids by putting their names on apples. I think you can do this
with dark green winter squashes too - the covered part is orange. Maybe
I should try it this year - I could get on the front page of the National
Inquirer (Face of Jesus Appears on Woman's Squash! Cucurbit Apocalypse
Predicted!)

It's more like old fashioned blueprints than photography, though.

OK, I said it was naive. But if it goes on to get you a Nobel Prize,
try to remember me in the speech of thanks!

I like the idea: dynamic videos on rhubarb leaves, perhaps. A new goal
for genetic engineering!

We should get together! (I've actually done the apple thing: it
works.) But I hope David realizes I was asking about the reactions
themselves, separate from the leaves.

Mike.