The way this technique works is not a standard film photographic exposure, the paper responds very differently in this process to normal processes. In effect what you have is the Sun burning a line onto the paper. This actually means that you don’t need to develop or fix the paper afterwards either. However, the final print does not last very long - the paper is still light sensitive when you take it out of the can so you need to scan it rapidly, in a dark room.
Here's a quote from the Solarcan (a premade product that uses the same principle) instructions:
> Inside the Solarcan is a single sheet of light sensitive photographic paper. Once exposed to light a chemical reaction happens to the emulsion and it begins to change colour. Traditionally photographic paper captures a latent image that is not visible to the naked eye and requires chemical processing, however with a Solarcan the light from the Sun is so powerful that as it passes across the paper it darkens visibly and no chemicals will be required to ‘develop’ the image.
Here's a quote from the Solarcan (a premade product that uses the same principle) instructions:
> Inside the Solarcan is a single sheet of light sensitive photographic paper. Once exposed to light a chemical reaction happens to the emulsion and it begins to change colour. Traditionally photographic paper captures a latent image that is not visible to the naked eye and requires chemical processing, however with a Solarcan the light from the Sun is so powerful that as it passes across the paper it darkens visibly and no chemicals will be required to ‘develop’ the image.
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