Re: Hello

----- Original Message -----
From: "Johanna Zamora" <jjjulep@yahoo.com>

> I am new to the list.

Welcome to the list!

> I am using a body cap with a larger hole cut out,
> about 5mm or 6mm and then I am applying soda can
> aluminum to it. Thin enough?

I'll work just fine! Later you can get some of the brass or steel shim
stock 0.002" or 0.001" thick, some of us use to make our pinholes.

> I will be using a 30 gauge syringe needle. Which is
> smaller than a pin. I called BD (manufacturers) and
> found the external diameter is 0.012mm.

Are you sure the diameter is 0.012mm?
0.012mm is extremely thin, a pinhole with that diameter would be optimum for
a camera with a 0,1mm focal length!!

> I have access to the needles, thinking they were
> pretty small. Perhaps another pinhole source is
> better?

A regular pin or needle is more than enough.
See the resources page in the Worldwide Pinhole Photography Day web site
http://pinholeday.org/support/ for help.

> So any ideas if this is workable? Is there anyone who
> can give me a concept of focal length for this?

You should be able to measure the distance from the the lens cap internal
side and the film plane, just mount the lens cap (with the center hole
already made to it), set the camera to MANUAL and select the longest shutter
speed available (30 seconds probably), fire the shutter and use a cotton
swab as a "measuring stick" (do it fast, as you only have 30 seconds before
the mirror comes back down, if the cotton swab still inside the camera, you
would certanly cause some damage). My Nikon has the inside of the lens cap
at about 48mm from the film plane, I'd assume your Minolta is not that far
from it. If you had to guess, go with 48mm or even 50mm as the focal length
of your pinhole set up.

BTW, if you have a GLASS lens with 50mm focal length, when using a tripod,
you could use it (the glass 50mm lens) to frame your scene, then install the
pinhole lens cap and make the exposure.

> Exposure times?

See the link above.
You could guesstimate your exposures based on previous results. But I
suggest that in order to have relative success at the beggining, you should
know what the f/stop of your pinhole set up is, once you know that, it is
just a matter of translating your camera meter readings (when the glass lens
is on the camera) to your pinhole set up. Again, see the link above for
instructions on how to measure pinholes with a regular flat bed scanner.

I'd suggest you start by making exposures using relatively high speed film
(iso400 and above) and under bright day light. But, if you are familiar
with RECIPROCITY corrections, by all means, use whatever film you want.

> I am using this size film to start out with because
> it's portable - well heck anything is portable :) -

Have a nice trip to Portland and make sure you share with us your results.

Guillermo
Received on Tue Jun 26 12:47:30 2001