Tuesday, September 13, 2011

Trojan Cat on Wheels

Trojan Cat on Wheels, originally uploaded by Henricus.

Taken with my Cigar Pinhole Camera.

Friday, September 02, 2011

Pinhole Photo (with edits)

Pinhole Photo (with edits), originally uploaded by Henricus.

My first pinhole photo! I love this new camera, it is a gas!

Thursday, September 01, 2011

Pinhole Camera by
Henry Chavez

I decided to build my first pinhole camera.  The first thing I did was to do some research online and see how to do it.  There are many great resources to be found on the web and coming up with a direction to follow was easy.  I’ll put the links at the end of my little missive here, if the reader is interested.  In order to streamline my first attempt, I made some quick construction decisions.  First I would not make the pinhole, I would buy one.  Second I used an existing film back to avoid creating a film carrier system.  Finally, I used a cigar box as my light box.  I chose a cigar box for the aesthetics and to save time.

Mucked it up!

As I was an avid cigar smoker I had a surplus of cigar boxes to choose from.  My first effort was totally experimental (my excuse for messing it up) and I mucked up a good looking Perdomo Corojo Habano box.  Having learned on this first box, I went on to the next box, an old Padilla Miami 8/11 box.  Here are the parts I used.

The Parts

  1. The box – Padilla Miami 8/11 Torpedo box
  2. Graflex 120 film back
  3. Pinhole - 500 Micron (by Lenox Laser)
  4. Closet door pull cup – ¾” polished brass

  5. 7
    Rubber O-Ring – ¾” outside dimension
  6. Krylon flat black spray paint
  7. Cabinet pull handle – polished brass
  8. J-B Weld Epoxy
  9. Elmers glue (not shown) 

My Calculations
Using an online calculator I found that the best size for my pinhole was 0.021”.  This dimension is based on the distance from the pinhole to the film plane.  Using this size hole would give me a 12 ½” diameter image circle.  This was more than enough for my little Graflex film back (model RH10, 2.25”x2.75”) and would avoid any vignetting.  I have three of these backs, so I sacrificed the worst of them for this project.  I bought a 500 micron or 0.020” laser pinhole from Lenox Laser.  They did not offer a 0.021” diameter.  The difference is negligible enough that I would still get an ample image circle and a useable f-stop of 322.

Cutting Holes and Scuffing
The first thing I did was to cut a ¾” hole in the middle of one end of the rectangular box.  This is where I glued the “closet door pullcup.”  I drilled a 3/8” hole in the cup itself.  The little Lenox Laser pinhole diameter is such that it fits perfectly in this cup.  I took great care when I drilled into the little cup as I did not want to scratch it up.  I will use the o-ring to hold the pinhole in place.  I did not make a shutter as the Graflex back has a dark-slide that will accomplish the same thing.  On the opposite end I cut a square that was large enough to expose the film on the Graflex back.

Hole-y Box

I used a Dremel tool to make quick work of this square hole.  I glued the Graflex back to the box with J-B Weld epoxy.  Eeeeek!  Yup, after careful deliberation, I decided to glue it and avoid making a removable contraption.  I haven’t used these backs in 15 years.  So I am actually giving this back a new and useful life.  In order for the J-B Weld to do its thing, I had to scuff up my surfaces.  However, I had to first remove one of the fitting ridges (see pics) on the back of the Graflex back.  This ridge is used to secure the back on a Graflex field camera and prevent it from sliding around.  On my project this ridge would prevent my back from laying flush.  I could have cut a slot in the wood, but since I needed to scuff up the surface anyway, I decided to remove it.  This was easy to do with the Dremel.  I also had to scuff up all the other surfaces to accept the epoxy, which included the Graflex back,  the closet pull cup and the cigar box.

The Hole and The Ridge

Here is a photo of the scuffed surfaces.  I actually used the Dremel to make slits in the wood to give the J-B Weld a place to seep in.  Please do not send me emails abou the Graflex back.


Glueing with J-B Weld
Using this product is as easy as using any other epoxy.  After everything is scuffed and the dust wiped off you simply apply the glue and hold the pieces in place and allow the glue to cure.  The closet pull cup was simple.  I wiped the epoxy around the hole and set the cup into place.  I was careful to wipe away any excess epoxy for a neat finished look.  I placed a film container against the cup and taped it while it set.  For the Graflex back I applied just enough epoxy on the back surface to secure its position on the cigar box.  Again, I was careful to wipe off any excess epoxy.  I secured the back with four binder clips.


 Although the Graflex back is made from alluminum, it is still a heavy part.  With that in mind and once the back was secured, I applied a small bead of J-B Weld to the inside edges of the Graflex back where the opening meets the wood of the box.  This made the bond more secure and prevented any possible light leaks.

Securing for Light Leaks and Strength

Painting The Light Box
Next I installed the brass handle to the lid of the box.  I had to shorten the screws that came  with the handle as they were intended for thicker wood.  Again, I made quick work of these screws with my Dremel.  I attached the handle at this point, because I wanted the screw heads painted black since they would be inside.  After the handle was attached I taped off the box in preperation for painting the interior.  I installed a cardbord sheet in the back (where the darkslide goes) to keep the paint out of the interior of the Graflex back.  I also put a piece of tape on the hole I made on the closet cup, since the backside would be painted black.  I did not want the paint on the shiney brass front of the cup.  Once the box was taped off I spray painted what would be the interior of the pinhole camera with flat black.

Taped for Painting
Painted Light-box
The pinhole is held in place with the o-ring.  The pinhole camera is ready to do its thing!
Pinhole Installation

I decided to use my only roll of 120 film, Velvia 100F.  In my excitement to get started, I installed the film backwards in the Graflex back and wasted a perfectly good role of Velvia 100F.  I reloaded with Velvia 50 and off I went!