Silver halide crystals

Many years ago I was given a guided tour around a photographic film company and they gave me a generalised view of the process.

In the very old days there were many ways to make photographs. The method that won was a black and white process based on Silver halide crystals. These crystals have lots of silver on them. They aren't black initially but they're ready to change to metallic silver (which strangely is black).

When light hits the crystal a tiny bit of silver gets changed to silver metal. The rest of the crystal remains unchanged until processed. When the film (or paper) is processed the first chemical uses the little bit of silver as a seed to change the rest of crystal to silver. The second stage of processing dissolves the unchanged silver halide crystals.

So how do you get colour? You cover each silver halide crystal with two layers. One to make the crystal sensitive to a particular colour of light and another layer to make the desired colour when the crystal is processed. The metallic silver and the unchanged silver halide are both dissolved leaving only the colour. Choose the colours for the layers to make the film either positive or negative.

Now it’s nearly all digital so all of the above is old hat! For those of you that are still pre-digital you are keeping the camera film industry alive. As soon as we stop buying film manufacturers will stop making it and our old film cameras will soon become a distant memory.

For those of you not yet sure about the 'digital age' of photography or who want to experience what it can provide before you move across why not hire a camera or lens to try it out.  LensLocker have a wide range of the most up to date digital photography equipment for hire so why not give it a go? 

We stock Sigma, Nikon and Canon lenses, soon we will be extending our range to include Zeiss.