[LargeFormat] New Memeber introduction/Pinhole day comments

[Jonathan King]

On Thu, 2 May 2002 12:09:55 -0700, Achal Pashine wrote:

>Schuyler, I converted my 4X5 camera into pinhole. Basically, I
>bought some
>brass shim from OSH hardware store and used the sewing needle=
 in
>combination
>with emery paper to create very fine and perfectly round=
 pinholes. I
>measured the size by scanning the pinhole and determine the=
 actual
>size by
>comparison to known scale. It was approximately, 0.3mm. It=
 worked
>best for
>17-20mm focal length.
>In the meantime, I had correspondence with another pinholer,=
 Chris
>Patton,
>also from Stanford University; he provided me with variously=
 sized
>copper
>Gilder grids (used in electron microscopy and are very cheap,=
 one
>can get
>100s for $10-20!). Gilder grids are very precise in diameter and=
 can
>be
>stuck onto larger brass shim squares with 3-4mm hole. It=
 produces
>incredible
>details.


Great idea!  I found  www.guildergrids.co.uk.  I think I'm going=
 to 
try them.  They seem to have distributors through Europe, North 
America, & Japan.
Thanks Achal!

Another source of cheap pinhole material that I have used for=
 35mm 
and 4x5 pinholes is aluminum soda cans.  Not as elegant as brass,=
 but 
effective.  One can is plenty of raw material for several=
 pinholes.  
The paint on the outside and plastic layer on the inside need to=
 be 
removed (sandpaper), but a few minutes work with several grits of=
 
sandpaper (I used down to 1500 grit) & a needle or fine drill=
 makes 
a nice pinhole.  I usually dimple the aluminum, then sand down=
 the 
bump to make a very thin opening, while the thickness of the rest=
 of 
the aluminum makes it easy to handle.

Last winter I lead a group of 10-11 year olds making 4x5 pinhole=
 
cameras using that technique.  Theirs came out fine, I find that=
 
about half of the ones I make are good and round (checked on a 
scanner)

My pinhole day activities consisted of turning a Speed Graphic=
 into a 
pinhole camera, so I don't have images to contribute there, but=
 I'm 
developing my first Speed Graphic pinhole negs tonight!