Intrepid pinhole projections

Pinhole experimentation with the Intrepid Camera.


My Intrepid 5×4 Field Camera is one of the original Kickstarter models. It came with a lensboard fitted with an 0.5mm pinhole, the optimum diameter for a pinhole camera with the pinhole set 140mm from the image plane, giving an aperture of f/280. (I refuse to refer to this distance as the ‘focal’ distance, there being no lens to focus, and instead refer to it as the pinhole ‘projection distance’ or ‘PD’ for short.)

I have used the camera with its lensboard pinhole on a few occasions, always setting the front standard at 140mm or so. However the camera’s bellows adjustment gives the flexibility to alter the PD to cover a range from about 60mm all the way out to almost 300mm. With a little spare time on my hands I decided to investigate the field of view obtainable at different PDs and to see whether any image degradation occurred due to using the fixed 0.5mm diameter pinhole at ‘non-optimum’ PDs.

I set up The Intrepid on a tripod with a selection of my grandchildren’s old toys, an old rabbit hut and an even older garden shed as subject matter. My plan was to make exposures on Ilford MGIV RC Satin paper rated at ISO 6, setting the bellows for 60mm, 100mm, 140mm, 180mm, 220mm and 260mm PDs and using the Pinhole Assist iPhone App for calculation of exposure times. In the event, I ran out of sufficient daylight to complete the series and made do with four exposures.

Here they are:


The developed paper negatives have been scanned, inverted, flipped and been adjusted for black and white points in Affinity Photo.

Pinhole exposures will never be sharp due to diffraction but I am unable to detect any noticeable image degradation over this range of PDs although only the third image is exposed at the ‘optimum’ PD. This points to the accuracy and cleanliness of the pinhole supplied with the Intrepid. Exposure times are all satisfactorily consistent, given that changing light conditions during longer exposures have an uncontrollable effect on the outcome, so my long-standing faith in Pinhole Assist as a great tool for pinholers is well justified.

There have been times when pinholing that I’ve wished I could narrow the field of view. I think I’ve found a solution!

Fixing a wayward pinhole

As someone more used to creating pinholes I took a twisted delight in sealing up one in the bellows of a junk-shop find.

Just a few weeks ago my younger daughter gave to me for Father’s Day, a Vest Pocket Kodak Model B camera that she had spotted in a junk shop window. She sure knows the way to my heart!

The camera was clean and appeared to be in good condition. The shutter worked smoothly and the aperture stop control rotated with just the right detent at each stop. The bellows were clean looked to be in good order and the lens assembly pulled out and clicked into place as it should. All that was missing was the scribe for the Autographic function – by sliding open a door on the camera back information could be scratched though the film backing paper and exposed to light to write the information onto the film itself.

Junk shop find for Father’s Day.

It took a bit longer to work out how to open the film chamber. Researching on line for instructions and other information identified that the camera was an early model. Production began in 1925 and in 1928 the method of opening the film chamber was changed from two sprung buttons on the side of the film chamber to a lever worked from the front. My camera has the sprung buttons on the side so is pre-1928. I also came across the suggestion that that my example, made by the Canadian Kodak Co. of Toronto was not only an early model but one that may also be relatively rare. On the other hand it is very common for these cameras to be found minus their Autographic scribe!

One of four apertures is set by rotating a disc situated in front of the lens: They are numbered 1, 2, 3 and 4 but with a bit of careful measuring I calculated them to be f/11, f/16, f/22 and f/32 respectively. The shutter has two settings, T for Timed and I for Instantaneous which sounds like something around 1/40 second. The final twist is that the shutter lever operates in both directions.

With all that information the camera took on quite an exciting prospect and I duly sourced a couple of rolls of ReraPan 100-127 black and white film with which to check it out. Fortunately there was an empty spool still in the camera so as soon as the new film arrived I was all set to load a roll and take some pictures.

The day the film arrived was cloudy and I only made two exposures, at the widest aperture setting. The remaining six exposures were made a couple of days later in bright sunlight with aperture settings 3 and 4. The film was developed in Ilfosol 3 diluted 1+9 for 7 minutes at 18°C, scanned and the files adjusted for black and white points in levels.

The light leak was pretty obvious. Even on the exposures made in dull light the triangle of overexposed image was clear. On the sunny day images the same area was obliterated. My ninety year old camera has probably been lying at the back of a cupboard or in an attic for many decades, hence its excellent outward cosmetic appearance and well functioning mechanicals, but it will have been closed up with the bellows tightly folded together. Opening up the camera, and time, has perhaps been just too much for the folds in the leather. A repair would be necessary to restore the camera to working order but given the overall condition I reckoned it would be worthwhile.

It’s been a while since I made a pinhole camera so I decided to turn the idea on its head and make a pinhole image to locate the leak! I took some measurements of the internal dimensions of the bellows and made a template for an insert. In the darkroom, the insert was cut from a sheet of MGIV RC Satin paper and placed inside the bellows with the emulsion side outwards. With the camera back in place, the film counter window taped over and the shutter closed I placed the camera outside in daylight for five minutes or so then returned to the darkroom to develop the insert.

From the developed paper I could be sure the light leak was from a single source, the position of which was easily identified. I made an initial repair with a small piece of electrical PVC tape. It was much easier to do than I had anticipated as the size of the camera allowed easy access to work the leather with my fingers from both sides. I finally remade my repair by taping all the way along both top-edge creases as it looked neater. I tested the repair with by exposing couple of paper negative exposures on MGIV RC Satin paper cut to fit the film chamber.

Paper negatives confirming that the light leak has been fixed.

The electrical tape is light tight and sufficiently thin and flexible to fold up neatly with the original leather of the bellows. With that small repair, I reckon I can be confident to load the second of the two rolls of film I bought and expect good results in bright light. Roll on the sunshine!

Recycling the Christmas packaging

When the turkey’s done, the pud’s been eaten, the bottles emptied and all are sick of sweets and chocs, there’s one more thing to do before trashing the wrapping.

With the Christmas festivities over, there’s nothing I like better than rummaging through the discarded tins, boxes and packaging in search of a potential pinhole camera.

Top of this year’s list was a neat cylindrical box that had housed some deliciously more-ish dark chocolate mint thins. Here’s how I elevated it to its true purpose! (click on the images to view full size.)

For the pinhole I use Art Emboss matt black aluminium foil – a roll cut into 2 cm squares makes a lifetime of pinholes, but the simplest pinholes are made by making a hole in a piece cut from an aluminium drinks can. To make the pinhole I use a punch/drill made from a cut-down eraser pencil with a pin pushed into the eraser (cut off the head of the pin and push it in with pliers). Lightsealing is achieved by the judicious use of sticky-backed felt cut from inexpensive sheets.

At this time of year the A&E department of the local hospital is likely to be busy so I took particular care using the craft knife when cutting the hole in the box over which the pinhole was to be placed. I use black PVC electrical tape, which is light tight, to stick the pinhole in place.

It took only an hour or so to convert my Mint Thins Chocolate Box into a Pincam, photographing the process as I went. I loaded the camera with a piece of Ilford MGIV RC Satin paper and gave an exposure of about fifteen minutes under the same lighting and of the camera I used to record the conversion. The camera lens was about 80mm from the pincam. Here’s how the paper negative and the scanned, inverted final image look:

Now, with Hogmanay coming up I’m sure I spotted a big tin box of shortbread and at least one Laphroaig cylinder box …

Coffee Can Pinhole Fun

Just a few more images made in the simplest of cameras.

On my last outing with a coffee can pincam, the images looked a bit fogged so I’ve been lining the insides of the cans with black paper to eliminate internal reflections bouncing light around.


So with my two coffee cans (and a drinking chocolate can) duly lined I’ve been taking them with me, one at a time, over the past week. Loaded with Ilford MGIV RC Satin photo paper, the paper negatives have been scanned, inverted and flipped.

Here are the results.

Hallowe’en Sunrise
The New-ish Old Pier
Winter Sun on the Harbour
Autumn in the Woods

RUFLI – the pinhole unit of measure

Pinhole photography is an excercise in the art of approximation and imprecision, a venture into the realms of serendipity.

Everything to do with pinhole photography is measured in RUFLIs: The diameter of the hole made by the pin can be fairly accurately measured but in reality a regular pin, for instance, makes a hole that is RUFLI 0.5 mm across, the distance from the pinhole to the image plane might be RUFLI 75 mm making the aperture RUFLI f/150. On a sunny day with regular photo paper the required exposure would be somewhere in the region of (i.e. RUFLI) ten seconds or so.

RUFLI should be pronounced ‘roughly’.

My mobility of late has been hampered by a torn calf muscle and photography has had to take a back seat. However, today I hobbled out with a tin can punctured by a pin, the hole sealed by a piece of electrical tape, and the screw-on lid sealed from light leaks by a strip of sticky-backed felt. Inside the can was a sheet of 5″x7″ Ilford MGIV RC Silk photo paper. My mission was to make a shoreline exposure of the paper in the can. Mission completed, here’s how it went.

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The observant may notice a few things in these photographs of the coffee-tin pincam:

  • The pinhole is positioned about three-quarters of the way up the can, not dead-centre as might be expected. This is not a mistake! When the pinhole is centred, so will be the horizon. By positioning the pinhole as I have I can raise or lower the horizon giving greater emphasis to sky or foreground depending on whether the can is upright or upside-down.
  • I’ve labelled the pincam with what look like accurate measurements of P.D., diameter and aperture, ignoring the RUFLI unit of pinhole measurement. This is merely an illusion created by the number of decimal places used. Had space on the label permitted, each parameter would have been prefixed ‘approx.’.
  • I refer to P.D. – Projection Distance. All too often the distance between the pinhole and the image plane is erroniously referred to as the focal length. However, ‘focal length’ correctly refers to the distance from the nodal point of a lens to the plane of focus of the lens. In a pinhole camera there is no lens and therefore there can be no focal length. Light projects through the aperture of the pinhole and continues to the image plane. ‘Projection Distance’ is simply the use of accurate terminology and is RUFLI correct.

For my image of the shoreline I wanted more foreground than sky so I turned the can upside-down.

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I developed the paper negative in Ilford Multigrade diluted RUFLI 1+9 at RUFLI 17ºC until it looked OK-ish in the darkroom safe-light. I only took RUFLI 35 seconds or so.

Once dry I scanned the paper negative and inverted it to a positive in software. After a bit of tweaking of levels, these are the scanned negative and positive images.

shoreline negative
shoreline positive

There. I’ve hobbled happily with a pincam and my leg is so much better now an image has been made.

I’m thinking the paper is a bit fogged and could do with a tad more contrast. That might be due to light bouncing around the exposed shiny interior of the can. A quick spray of the inside with flat black paint should solve that for next time. Or it might be that the bedsheet I used to create a dark space in which to load the paper into the pincam was only RUFLI effective …