To get a positive from a paper negative, scan the dry negative and invert its values in image-editing software, or contact print it onto a second sheet of photo paper, exposed for a few seconds to white light and then developed.
Your sheet has come out of the fixer, been rinsed and dried, and at last you are holding the image. Except that it is the wrong way round: the whites are black and the shadows are light, because the paper has recorded a negative. That is normal, and it is the next step in the process, the one that turns this paper negative into the positive image you were expecting.
This work starts exactly where the developing of the pinhole photo stops, with the dry negative in your hand. So there is no need to go back over the developer, the stop bath or the fixer here, as they belong to the previous step. As the pinhole photography guide points out, there are two ways of getting the positive, and each has its own logic.
Scanning the negative and then inverting it
The most direct route is to place the dry negative on the glass of a flatbed scanner, scan it like an ordinary sheet, then invert the values on the computer. This operation is called negative inversion, and every image-editing application offers it in one form or another, which makes a detailed tutorial unnecessary here.
The image then flips at once: the blacks turn white again and the picture reads the right way. You keep the paper negative intact, you get a file that you can print or share, and the particular grain of the pinhole look is preserved in the scan.
Scanning at a generous resolution
One detail deserves attention: the grain and the fibre of the paper also show up in the scan, and it is better to scan at a generous resolution to keep them fine rather than see them clog up. In workshops, this is the route most beginners choose, because it uses up nothing, can be undone and gives a result in a few minutes.
Making a contact print
The second route remains entirely analogue and gives you back an image on paper, without going through a screen. It is called a contact print, because the negative and a blank sheet touch face to face during the exposure.
The principle is simple. Under the red safelight of the darkroom, place the paper negative directly on a second sheet of light-sensitive paper, with the sensitive sides against each other.
Then give a brief exposure to white light, just a few seconds, the light passing through the negative to expose the sheet underneath. Where the negative is dark, little light gets through and the paper stays light; where it is translucent, the light gets through and the paper darkens, so the values are reversed a second time.
Finally, develop this sheet in the usual three baths, and this time the image that comes up is a positive, since you have inverted a negative that was already inverted.
Finding the exposure through tests
The exposure time depends on the density of your negative and the power of your light source, and there is no single value.
In practice, cut a thin strip of blank paper, slide it under the negative and the glass, then expose it while gradually covering its surface with a piece of card, so that after developing each band corresponds to a different time. The band with the right contrast gives you the time to use for the full print.
Note that this method uses a second sheet for each positive.
The light and the duration of the contact print
To print the positive, place the dry paper negative face to face with a new sheet, under a clean sheet of glass, then light the whole thing with an ordinary lamp, working under safelight the rest of the time.
The duration depends on the power of the lamp, its distance and the density of the negative: allow anything from a few seconds to a few tens of seconds, and pin down the exact time with a test strip before printing the final sheet.
Which route to choose
It all depends on what you are looking for. Scanning gives you a file in a few minutes, with no extra chemistry, and suits you when you want to share the image or simply see it the right way round. Contact printing takes more care and a second sheet, but it gives you a photographic object in its own right, a positive on paper with the texture and depth of an analogue print.
Nothing forces you to decide once and for all, either. Many people scan each negative first to keep a digital record of it, then save contact printing for their favourite images. Whichever route you take, the paper negative is never an end in itself, and it is by transforming it that the pinhole camera finally delivers the complete image.
Éric Marais — Photographer, author of two books on pinhole photography (published by Pearson) and creator of the Sténoflex. He has run introductory workshops in pinhole photography and analogue developing from the very beginning.