Pinholes in Scotland

Did a day trip to Scotland whilst I was on holiday in the Lake District.

The 8x10 setup on a tidal loch. There was no where to place the tent pegs, so I had to tie the guy ropes around rocks. There was no wind, so hopefully there will be no blur.

The 8x10 has an effective aperture of f/400. This gives an exposure time of 10s.

I should really add the exposure compensation in the reciprocity app (and I should take the screen shot before the timer counts down too). I metered at ISO 50 which is why there’s no compensation showing. The adjusted exposure for reciprocity is 33s.

Next I move on to the 4x5 camera. I wanted to get a similar photo to the one from the 8x10 so I can get a feel for the sharpness, field of view, etc between the two cameras.

The 4x5 has an effective aperture of f/200. This gives an exposure time of 5s.

Again, I metered at ISO 50 instead of ISO 100, so the meter reading already has +1 stop of exposure compensation. Taking reciprocity into account gives 11s of exposure.

Making a Wooden Box for my 4x5 Film

I wanted a small wooden box to hold two packs of Shanghai Pan 100 sheet film. I had some nice beech hardwood that I could use.

Using the ‘shooting board’ and plane to make the ends square. I planned to use use butt joints for this as I am about to go on holiday and I want to take the finished box with me.

Quick glue up using a box clamp.

Some boards I had previously glued up for a different project that went nowhere. These would be the top and bottom of the box.

The boards glued on the top and bottom and a heavy weight added. In the future I will use clamps, as this didn’t work so well.

Closed box with oversized edges. Next to trim down the edges, then cut the box open.

I used a little wooden block plane to trim the boards down to size, along with a sander when close.

Looking good so far.

Carefully cutting the box open by hand.

Success!

Gluing little pieces in to held keep the lid in the right place as the box closes. This will also help the clasp align.

The clasp I plan to use.

Hinges and clasp fitted.

The shut line is a little uneven

But the two boxes of film fit like a charm

I adjusted the hinges a bit to get a better shut line, then gave it a nice coat of bee’s wax furniture polish. Job done.

Pinhole Camera – 4x5, 60mm – Test Image

After the paint had dried on the inside, I took the camera out for a test.

The 0.3mm pinhole has an effective aperture of f/200 for the 60mm focal length. This gives an exposure of 10s with +1 stop for reciprocity failure compensation.

Which I timed on my phone.

And then used the ‘Massive Dev Chart’ app to help with the development (awesome app, you should get it). I processed the 4x5 sheet film (Shanghai Pan 100, aka ‘GP3’) in Rodinal at 1:49 dilution.

I normally print my negatives, so wasn’t setup to take a scan (photo) of a 4x5 negative. I placed the negative on my tablet computer. This resulted in a bit of a weird image (as you can see the pixels) but was good enough for a test.

With the image inverted in GIMP. The grey area on the left is an inverted white reflection of my ceiling. Good enough for a test. Looks like I needed to add more reciprocity failure compensation.

Pinhole Camera – 4x5, 90mm (Build Part 2)

Minor update on the 90mm focal length pinhole camera. I sealed the joins with black silicone, then painted the inside with matt black chalk board paint. I made sure to cover the shiny brass bolt in lots of paint so it doesn’t reflect.

Pinhole Camera – 4x5, 60mm (Build Part 1)

This is the second pin hole camera I started to make, and the first I have finished. The last camera was made out of Oak and used butt joints, this one is made out of Mahogany and uses dove tail joints.

Cutting the tails and pins.

A closer look… these were my first dove tail joints and whilst ok they weren’t as good as I’d hoped.

Test fit. They fit together fine, but not as close as I’d have liked.

I’d previously created a wider board by joining two pieces of stock together. In this case a cut the second piece in half, so I joined a half on either side of the first piece. I did this so I wouldn’t have to drill a hole for the pinhole on the join. I really wanted to see how the wood would look with a finish, so added some bee’s wax.

I glued up two more pieces of stock for the back, this time I didn’t need to worry about the join being in the middle.

I added a border for the film holder to fit into, and also cut a channel for the notch on the film holder to fit into.

I cut a notch out of the side of the camera to let the film holder sit inside the box slightly so that the edge didn’t line up with the light seal. I added a lip all round the inside of the camera for the film holder to sit on.

Test fit of the film holder. Once it fit correctly, I could add the hinges to allow the back to open to accept the film holder.

Hinges added. I used brass ones and made sure to recess them.

The film holder fits in quite snug.

I still need to add some felt to act as a light trap. This will also give some spring for the catches to work with.

Next I drilled a hole for the vertical spirit level.

And same again for the horizontal one.

Next I did the same for the tripod mounts.

And again…

With the tripod mounts and the spirit levels epoxied in, I added the catches.

And drilled the hole for the pin hole to be installed. The pin hole will be glued on the inside, but I need to make sure that the outside won’t vignette as the wood is quite thick here, hence the step cuts.

I added opaque sealant (black silicone) to the seams and a felt light trap. This also adds some pressure to the catches (which I had notched anyway to stop them flying open).

Building the shutter, here you can see the holes for the magnets, and the magnets themselves.

Holes drilled in the camera body ready for the magnets.

I used the same black silicone sealant to glue the pin hole into the camera, then painted the inside of the camera with chalk board paint.

Next was some furniture polish.

All ready to go!