Regarding cyanotype:
Pre-coated papers and chemicals are available from:
Blue Printables
P.O. Box 2254
Vashon Island, WA
1-800-356-0445
www.blueprintables.com
A 'step drill' tends to do a better job
in thin sheet metal than a normal
twist drill.
It should be noted that the cosine to the fourth power rule
applies only to cameras where the film is flat. Cameras
that are half cylinders or whole cylinders, like the classic
oatmeal box cameras have different falloff patterns.
A Google search on 'panopin' turns up:
http://www.ibvr.com/NewFiles/Pinhole.html
On a just slightly serious note, it might be an interesting
experiment to take pictures with pinholes made with
all of the methods listed in this discussion and exhibit
them along with the pinholes and even the object that
made the hole. There are certainly a lot of ways to make
a hole in somethin
Rob Duarte and I will be giving a two day pinhole
class at Cambridge Center for Adult Education
for Worldwide Pinhole Photography Day,
April 26-27. We will make cameras out of
various containers like oatmeal boxes and
cigar boxes and use paper negatives to make
images. Info at: www.ccae.org
Murray asks about resolution vs format and asks if resolution increases
as the format gets larger.
Assume that you keep the same angle of view for each format and use the
optimal pinhole for each format.
In absolute terms, resolution in lines per mm goes down as the format
gets bigger,
because th
A 'step drill' works well in thin sheet metal. Much better than
a normal twist drill. Places like Home Depot have them.
There's a picture of one at:
http://www.widgetsupply.com/Power-Tool-Accessories/drill/step-drill-bits/BCZ24-2.jpg
Ian McKee writes:
> ... stuff snipped ...
> Calumet sells a set of twelve pinholes ranging from .0059" to .032". I
have
> mounted these on a 4" x 5" camera and shot the whole series at an
> arbitrarily selected bellows extension=focal length of 210 mm. With
each
> pinhole I get the same image and
erick...@hickorytech.net writes:
> Here's a question that has troubled me for a long time, since we've
gained
> the attention of the physicists among us. If the optimal image occurs
when
> all light waves are 'in phase", which the Young article says occurs at
the
> junction between the nearfield a
luish m. coelho writes:
> a glass of water with a straw inside is a simple example.
> you see the straw bent but it is not.
> thats what happen with light when it changes the medium it is
travelling
> (from air to water or through the glass, example). I am not sure about
> what happens with pinho
Ed Nazarko writes:
> And many lenses, even very good ones, have diffraction fringing at
small
> apertures. ...
Diffraction cannot be avoided, it's the way light behaves when going
through any
system. Every lens, telescope mirror and pinhole has diffraction. The
best optics
are said to be 'diff
erick...@hickorytech.net writes:
> It occurs to me that lack of sharpness in pinhole images is not
inherent to
> the nature of diffraction photography. It is caused by lack of
precision in
> matching the diameter of the pinhole to the distance to the film, or
in less
> than perfect pinholes. Thus
John Brownlow asks about pinhole diameter.
I did some experiments with a set of pinholes I have. It seemed to me
that the optimal
pinhole as determined by the formula did produce sharper results than
smaller or larger pinholes.
The formula that I use does not refer to the outer diffraction ring
I helped Rob Duarte give a pinhole photography class at the Cambridge Center
for Adult Education in Cambridge, MA. on Saturday and Sunday morning. We had 8
students although one of them was there mostly to get information and
references and didn't build a camera or come back on Sunday. There were
I just got a copy of an Ilford Manual of Photography from the 1920's. What we
call filmholders are called dark slides in the book, and what we now call
dark slides are called shutters. And a cable release is called an
'Antinous Release'.
A beginner may want to use an ortho sheet film to start with, since it can be
handled under a safelight. Ilford Ortho Plus is an example. They may also
want to see what films are available through Freestyle Sales and Photo
Warehouse since that may be less expensive than going to the local camera
The latest flyer from Calumet Photographic has the Zero Image multiformat
camera for $120.00 and the Eric Renner book for $26.99.
www.calumetphoto.com
Consider adult ed classes or workshops. At the Cambridge, Mass adult ed
program there has been a class that does pinhole. I took it a couple of
years ago. Adult ed can reach a large audience.
For anybody thinking about a large camera: remember that the camera
does not have to be shaped like a cube or rectangular solid. It doesn't
need all that inside volume. You only need a clear line of sight from
pinhole to film, so the camera could be shaped like a pyramid. Or
it could be cone sha
It's easy to make a dial calculator like the one on an exposure meter, but
that goes to longer exposures and slower film speeds. I've got one on
my web page at http://linux.bbn.com/~koolish
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