This is the first of several posts that will address how to control the basic settings on your SLR camera. An SLR is the big camera that you can change lenses on. SLR stands for Single Lens Reflex as there is only one lens. There are also Twin lens reflex cameras out there that use 2 lenses one on top of the other, these are pretty rare.
The primary settings for your camera are – shutter speed, aperture, ISO and exposure. You have to have a combination of these in order to get an image that comes out looking the way you want. I will briefly outline these settings here then subsequent posts will address each in more detail.
Other settings and variables such as light, white balance and flash will be addressed later.
Shutter speed is expressed in seconds and controls how long the shutter is open to allow light to reach the sensor or in the old days, the film. Shutter speed is one variable that controls whether the image will be sharp or not. A 1/500 second shutter speed is fine for the sitting bird but is too slow for the flying bird which results in a blurry bird.
Aperture is expressed as f stops and controls the depth of focus. When you focus on a subject, f stop is one variable that controls what is sharp or blurry in the image. Below I focused on the middle spike of the fence, at f 2.8 only the one spike is sharp, but at f 32 all of the spikes are sharp.
ISO is how sensitive the sensor or in ages past, film, is to light. A low ISO needs a lot of ambient light while a high ISO can render an image in low lighting at the cost of increased grain or noise in the image.
Finally, exposure puts all of the above together. Exposure is the result of combining a shutter speed, aperture and ISO setting under ambient light to give you an image that is not too dark or too light, but looks just right. This is where the art of photography comes in. Balancing the settings to get the image you want.
Next time we’ll look at shutter speed in more detail.
