My “Day I Left Pennsylvania” led me to some archived website posts (before blogs were invented) I had written many years ago. I’m re-posting them now. Bear in mind that most of the content in this series is over 5 years old. I have left the content more or less intact. I have removed some links and added some others — but that’s it. Enjoy!

I went to the Ohio Institute of Photography & Technology for approximately a year. I think it was 3 semesters total. Took a lot of really neat classes, and a lot of really good (in my opinion) shots. They’ll be up here some day. I also learned a lot of the very precise and interesting aspects of shooting well-composed photos, and I’d like to share them here. The following is some of the very basic rules and laws that are involved in shooting photos of any kind, be it digital or wet, large format or slides. They’re even just good rules of composition period.

The Law of Reciprocity

This is the most fundamental law of photography. It is derived from the basic idea of balance. All things must remain equal in order for the the end result to be satisfactory. The law is:

Exposure = Light x Time

What this is saying, in more simple terms, is that to have an exposure (eg. a “picture”) you must have light, and the light must shine for some amount of time. Make sense? In order to apply this we need to get a little more specific though:

Exposure = Aperture x ShutterSpeed x Film ISO Rating

Now we aren’t literally multiplying one by the next, because that would give us a very weird number, the important thing is to remember that if one of them goes down, one of the others must go up. The balance is very important to maintain the same exposure.

“Stops”

a Stop is the units that we measure the amount of light exposing the film. If we increase our exposure by one stop (to over-expose it), we say we are “opening up a stop”. Decreasing the exposure (to under-expose) is “closing a stop”. Each stop in either direction either doubles or halves the amount of light, respectively. Opening up two stops allows 4x as much light (double, then double again). Closing one stop allows 1/2 as much light to enter. Remember that if we open up a stop in aperture, we must close down a stop in either shutterspeed or film ISO rating, and vice versa.

Aperture

This is the size of the opening in the camera lens. It is measured in “f/stops”. For example “f/1.4″ would be the largest aperture and “f/64″ would be a very small aperture. The actual number is determined by the ratio between the opening size and the focal length of the lens, but the sequence of f/stops is consistent from lens to lens, and goes as follows:

It is important to remember here that opening up from f/5.6 to f/4 is DOUBLING the amount of light that is exposing the film. Opening from f/5.6 to f/2.8 is QUADRUPLING the amount of light (following that would be 8x as much, then 16x, etc. It is a base-2 progression).

Shutter Speed

The length of time the shutter stays open. The shutter is the mechanical device inside the camera body (or sometimes is attached directly to the lens, such as in large and medium format cameras) that opens and closes very quickly to control the light that hits the film. Shutter speed is measured in fractions of a second, all the way up to whole seconds. The former being a short-exposure and the latter being a long-exposure. We have a similar progression in shutter speed:

In this instance, as with aperture, moving from one to the next increases or decreases by one stop, meaning we double or halve the amount of light, respectively. An interesting side note: you can hand-hold your camera (meaning no tripod and no flash) at the shutter speed closest to 1/focal length of the lens. So if you are using a 135mm lens, you can handhold at a maximum of 1/125. A lens with a focal length of 58mm (your “standard” sized lens on most SLRs) would give you 1/60 maximum– then either flash must be used, or a tripod. If not, you will probably get a blurry exposure. Kodak made the “Sunny 16″ rule which says that on a sunny day, with even lighting, you can hand-hold a camera at f/16 and 1/60 and get an even exposure.

Film ISO Rating

The arbitrary number assigned to film that designates the speed at which the film can be exposed. Higher ISO ratings means it exposes faster, but in the end it will look somewhat grainy. (The chemicals that are photoreceptive are larger, which is why they expose faster, which causes less fine-detail) Lower ISO ratings give you better quality in large prints, but must be exposed longer (due to smaller photo-receptive chemicals). The ISO ratings also have a number sequence which must be followed:

While you can technically set your ISO rating to whatever you like on most manual cameras, it’s usually a good idea to stick with the ISO rating prescribed by the film container. At least until you are comfortable enough to do some experimentation. :^)

Example Exposure Situations

The following table shows a listing of various exposure combinations that will all give you EXACTLY THE SAME exposure. (for this example, we will leave the ISO rating at 200)

So if you have metered a shot that happens to expose evenly at f/16 @ 1/60, but you want to capture some motion (meaning you want a longer exposure) you would move towards the right (i.e. 1/8s @ f/45). Or, let’s say you wanted a shallower depth-of-field, which you achieve by using a large (low numeric value) aperture, you would move towards the left of this table, (i.e. 1/500s @ f/5.6). Get it?

Composition Basics

Some people just naturally take good pictures. Fortunately this is a learned skill and not just an innate one. There are some really basic rules to follow to help keep your subject balanced. The first, and most cardinal, is the rule of thirds.

If we say that the table to the left is your viewfinder, then we will imagine it being divided horizontally and vertically into thirds. Anything of importance should be placed on the intersections of those lines. These are the focal points of the picture, and have the most strength visually. They allow for breathing room on both sides, and give an ideal of balance to the photo, even though they would technically be considered “off balance”.

One common mistake by casual camera users is to frame their subjects directly in the dead-center (eg. center column) of the frame, usually under the idea that it is “balancing” the photo. You will find your pictures are much more dynamic and strong compositionally if you align your subject with one of the two vertical lines. Even better yet would be to have a situation where not only is the focal point lined up with one of those columns, but the other column is a contrasting figure, such as an opposing or complementing color, a shadow or highlight, or anything to balance the photo out.

(This isn’t to say that there aren’t times when a dead-center alignment would be preferable — portraits frequently use centered-focal points, however they often also use asymmetrical lighting, so there is still some variation and balance. If you’re new to composition, stick with rule-of-thirds in the beginning)

In this particular example, shown above, you’ll note that the red dots (which were added, obviously) are right on the intersections. You’ll also note that both the center of the subject’s forehead, as well as his mouth, are both lined up with those dots. His head technically takes up approximately half the frame, but it is centered on that left vertical axis. The right half is empty space, which balances out the frame by giving the subject what I call “breathing room”. Compare that layout to this one, where we center the picture on the face:

While this picture may be centered, it looks an awful lot like a mug-shot. Good for informational purposes, but very cramped and does not allow the eye to wander at all. It’s pretty straight forward, like if Joe Friday from Dragnet were to be shooting photos, this is how he would shoot. “Just the facts ma’am.” No dilly-dallying about here. That missing third of the picture really has a big effect on the overall composition of the photograph. I happened to get lucky with how precise my visual “eyeballing it” of the axes was, but if you are at least aware of the vertical axes when shooting, and guesstimate it, you’ll find your photos to be a lot stronger.

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