And Last - It’s a Matter of Self Control
If you always took pictures of exactly the same things, in the same environment and wanting the exact same resultant photographs, you would really need only one control. A button to push when you wanted a picture. Obviously that scenario doesn’t fit the overwhelming majority of us.
We take pictures indoors and out, in full sunlight and in shadow, of objects moving and still. And, we desire different perspectives on those same photos, from intimate closeups for portraits to stark almost surrealistic vistas for imposing landscapes, and many variants in between.
To allow you to accomplish these goals the modern camera is equipped with a sophisticated control system to monitor and manage several factors, the most predominant and commonly discussed of which are:
1) Shutter Speed — this is the length of time (normally in fractions of a second) that the shutter will be open, allowing light to shine on the camera sensor.
2) Aperture — think of the pupil of your eye, expanding and contracting with changing light levels and you have a good idea. Aperture relates directly to the ability of the lens to allow light to pass through to strike the sensor. (see the diagram below)
3) ISO (sensor sensitivity) — I said I wouldn’t be discussing this, but I lied (sort of). I will only touch this at a very high and simplistic level.
In the beginning, all of these control decisions were made and implemented manually. You have probably seen reenactments of 19th century photographers telling their subjects to smile and then removing a lens cap by hand and counting or watching a clock, before covering the lens again. No wonder the old time portraits looked so stiff! People had to literally grit their teeth and hold their breath to keep from blurring pictures due to the long exposure times used. Long exposures that were needed because the photographic media was relatively insensitive (Low ISO) and the apertures were fairly small (small diameter lenses and lens openings) which meant not much of the available light striking the capture media; in this case chemical films on glass or tin plates.
Again, this has been a very brief overview of camera basics. I plan on covering some of these topics in greater depth in later articles, time and reader interest permitting. Now, I will turn our attention to the most important part of the camera, the part attached to the shutter button, which of course is YOU.
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