Exposure, from my A - Z sewries

Exposure!

Exposure is probably the single most important concept in photography! The use of the word comes from the origins of photography where a light sensitive material was exposed to light to make the image. The process has gone through many iterations of glass plates, light sensitive chemicals and materials, to the present day sensors.

The exposure of a photo is the combination of three basic components, all to do with light. That’s why its called “photography” writing or drawing with light!

The first is aperture, as discussed above. The second is “shutter speed”, this is very simply the amount of time, that the light sensitive material is actually exposed to the light. Finally, sensitivity of the sensor is called ISO, which will be discussed in much more detail, under “I”

By adjusting any of the three components – aperture, shutter speed or ISO, the appearance of the image can be altered. Each one of the three, is dependant on the other two. Phones and cameras in “auto” mode make an assessment and shoot an averagely exposed image. That is the point, Its average!

I like to adjust the critical three elements to get a superb image. I can make it lighter, darker, more or less shadow, how much is in focus or not. I can shoot in near darkness or in bright sunlight. I use artificial lighting, which I love. I can use light to emphasise and de-emphasise certain parts of my client’s face, to get the perfect image. I will discuss a bit about artificial light in the next post.

I have several whole books, just written about exposure. Getting the exposure as the photographer want the exposure, is the biggest challenge.

When I press the button, called the shutter release, and there is a very satisfying feel and sound. I have an idea what the image is going to be like. I describe that moment as an "exquisite pleasure". Later, when I develop or process the image and it has come out as I want it, that’s the moment, that is when I know I have made a good image!