There are really only three things you need to know about your camera equipment. Forget about all the bells, whistles and buttons – those are there to sell more cameras. Most of the people I meet through my training and meetup groups want to know how to use every button on their camera. But the key thing is to understand these four essential controls: Shutter, ISO, focus & aperture. Despite the many differences between analogue and digital cameras, there are still only three things to understand when you’re ready to shut off the “auto”button and go fully manual.
One, the camera is just a dumb black box that admits, for a measurable amount of time, a measurable quantity of light through to the recording substance, either film or a digital sensor. Exposing for quantity of light is achieved via the shutter, a simple device that allows for precisely timed allowances of light, no more and no less.
Sensitivity adjustments are available on digital cameras. By adjusting the ISO setting, you are doing the same thing as changing the film roll for another of a greater or lesser sensitivity.
Secondly – the lens (a more complex piece of equipment) also does two main things. It allows you to focus the image onto the recording substrate – either sensor or film, plus it allows a precise amount of light to strike that recording medium, depending upon the size of aperture. The larger the aperture opening, the more light is admitted at the time of exposure.
These days, focus is usually achieved through autofocus, but I try to get my students to focus the image via the focusing ring. If the lens you’re thinking of buying looks like the one below, with a tiny little focusing ring, get something else. These are the bane of digital lens economy. Most of them give more space to the zoom than the focus ring. It should be the other way around. You always need to focus, you don’t always need to zoom: The best way to get a photo is to move your feet.
Thirdly, you have to understand that the camera “sees” the world differently from the way you and I do. Our lenses and brains do innumerable adjustments to make sense of the world. We adjust for shade, colour, brights spots, and we even fill in things that we can’t really see. The camera is both an objective, non-adjusting machine that captures reality, and a highly distorted instrument that takes photos through its own mechanical biases. But that’s for another day: Each aperture, ISO and shutter setting has an effect on the photograph. That’s the hard part.
Which brings us to the question: Why go manual in the first place? Simple. Only when you start seeing as the machine does can you begin to bend the instrument to your will.