Article

A Pinhole for your DSLR

Please read the article on pinhole cameras if you have not already done so, even if you think you know all there is to know about pinhole cameras.

You may also like to look at the 5 minute project Pringle tube pinhole camera. 

Most modern DSLR's can be used as pinhole cameras and in this and two further short articles, I am going to look at:- How to do this, including instructions. Look at the factors that allow you to get better pinhole photographs. How to get a zoom/wide angle effect. How to simulate the rising front on a camera to allow taller buildings to be photographed without them leaning backwards. Pinhole photography is useful in helping you to understand photography better, as well as a fun or interesting thing to do. It does not produce the quality of image that you would routinely wish to use today, however there may be occasions where you feel it would be the solution, where you don't have the lens with you that you need.

Image taken as a part of this experiment using a Nikon DSLR, no lens but a pinhole in foil, on card instead. ISO 640, 2 seconds, pinhole in foil, on card over tubes.

To be able to make pinhole images, we just need to turn the camera to manual, so we can control the Shutter Speed, and so that the camera does not object to having a lens missing to meter with.

We can then remove the lens and replace it with something that blocks the light from entering and allows a pinhole to be positioned. The most common way of doing this is to use a camera body cap, drill a hole in it and put on the front, over the hole, something very thin that can have a pinhole in. A flattened out section of a thin aluminium can such as those used to provide drinks, is often used.

For the experiments here, instead of the body cap I have used a set of tubes, that are usually used for Macro Photography. This has a telephoto affect compared to the body cap, which gives the widest angle that you can get.

Tubes, shown above, have no lens/glass in them, they are just spacers. They normally come in sets allowing you, from a set of 3, to have 7 combinations of thickness. You could equally use any other attachments you happen to have such as an adaptor for a scope or microscope.

To do this we need:- camera tripod cable release (although I could have used the self timer) a set of tubes black card, thick enough that light can't go through it kitchen silver foil, small piece, could instead be a piece of a chocolate bar wrapper small needle or pin something to make a larger hole, I have used a piece of pointed wood that corn on the cobs are provided on at a KFC elastic band or two cellotape   Most of the items are shown in the image on the right

What to do

1. Cut a circle of black card, a little larger than the tubes, and cut inwards to just short of the tube diameter so that the edges can be easily folded in.

2. Use the pin or needle to put a hole in the centre of the card, then the larger device to make a larger hole.

3. Cellotape at ends, the silver foil onto the outside of the card.

4. From the inside, pin prick the smallest hole you can in the foil that you can see through the hole, as near to the centre of the hole as you can. Hold it up to the light and check that you have only one very small pin prick. (See image below at this stage).

5. Put the card now over the tubes, with the silver foil on the outside, and use the elastic band to hold it in place.

6. Take off your camera lens, and put on the tube set.

7. Turn the camera to manual.

8. Set the ISO at 400 and the shutter speed to 5 seconds.

9. Put the camera on the tripod and point it in the direction you want to take a photo

The piece of card with foil under, showing the pin or needle prick in the centre of
the foil showing through the card, shown larger than real size.

Camera with no lens, but a  pinhole in foil, on card over a tube. Exposures can be
 setoff with the self timer or by using a Remote cable (shown) or radio remote.

Taking the photos with this setup Ignore the exposure meter.   Take a photo, adjust your position or Shutter Speed,   to capture the subject better. You can see the curve to get a good idea of how much to adjust the exposure by. Make the shutter speed longer i.e. 20 seconds to make it lighter, shorter i.e. 1 second to make it darker, to start use halving or doubling (1 stop) or more, between steps to get approximate, then use finer adjustments if necessary. If it does not work, then usually this is because something is blocking the light, it could be a piece of the card from the hole you punched or  perhaps the foil/card is not laying flat enough. If you have a flip up and down piece with the foil, on card then you would be able to get a liveview image of the pinhole effect from the larger hole in the card to line the camera up, but as the picture quality would be poor, you can put back a smaller pinhole to capture the image.

Image taken with a D300 as part of this experiment 2 seconds ISO 200, pinhole and two smaller tube elements. As you can see it's an image, but not as sharp as you would get with your camera with a quality lens attached.

Improving the Image

It does not help that we also included pictures taken on a D200 with a Nikon lens on this page showing the parts and D300 set up, if you had just pinhole images alone, they would not look quite as un-sharp, they are about the same level of sharpness as you get from a cheap camera with a plastic lens, that many are quite happy to use.

We could however improve on these, with time and more experimentation, but here we have stopped at what you can achieve very quickly.

In theory the smaller the Aperture or f stop the clearer your image should be up to a degree, f stops are the hole size divided by the distance from the pinhole to the focal plane of the camera. With Pinhole Photography measuring the distance is easy, measuring the hole isn't. But generally images are improved by having a smaller pinhole. Images using the tubes should be better than those that can be produced with a body cap alone, although the body cap could be used instead of the card on the tubes as it has the same function.

The other factor is the thickness of the material you have the pinhole in, as the walls of this cause a varying of the light towards the edge of the images. This is why we have used the foil instead of just putting  a pin prick in the black card. Some people prefer a piece of aluminium can and sandpaper this down so that its very thin.  We didn't here as we wanted to produce an experiment that anyone could do very easily.

The subject needs to be well lit, preferably with the light from behind the camera position.

You maybe able to adjust some settings on the camera, for example on recent Nikon cameras you can use the picture control, and increase contrast, sharpness and saturation a little. You will also find the colours are better if you set the white balance for the correct lighting conditions i.e. sunny, shade etc.

Try a number of versions of the above, you will find every pin prick that you do differs in size, and therefore the exposure  and image quality also varies. Try to touch lightly so that only the tip touches and the hole is the tip rather than the shaft size.

If you use a complete piece of silver foil instead of the card, you will find there is too much bounced or reflected light and the image is damaged.

Its tempting to turn the ISO up high to cut the exposure times but this creates noise even at ISO values that normally in your photography does not show noise.

Many of the experiments I do are out of a window and like all window shots the image quality is reduced.

You can machine a brass or other shim far thinner and make up a slide for this, complete with black blocking pieces, but here I have tried to keep the instructions simple enough that just about anyone can do it with very little in the form of special equipment.

Commercially produced pinholes

There are a number of people producing pinholes that you can use with your camera, we have some contacts and details of what they offer at the end of Pinhole cameras - further information.   We also have as an example a gallery of images that we have taken using ones of these adaptors,  see Stanton Drew Stone Circle - Pinhole Gallery to see what can be achieved outside.

See Also: Two further articles expand the coverage here using the same techniques:-

Using a pinhole to Get a zoom/wide angle effect 

Using a pinhole to simulate the rising front on a camera

In addition we have the following articles that may also be of interest:-

Experimental photography

Pinhole cameras

Pringle tube pinhole camera  

Pinhole cameras - further information