We’re into the 72nd installment of this column and it seems that we’ve not gotten into the basics of photography yet.

The idea behind the whole column was, of course, to just shoot and not let too many technicalities get in the way but many of you, in the desire to get more out of your photography than snapshots, might have started to feel a bit restricted by all the automatic modes and would want to get your feet deeper in the mud.

There’s this story of a battle in England where peasants who had nothing but axes and pitchforks slaughtered well-trained and armed knights. This battle happened in a very muddy area where combatants had to deal with knee-deep mud which restricted the movements of the armored knights. While they stood there helplessly flailing away at the more mobile and unarmored peasants, they were almost like dummies made for thrusting exercises.

The technicalities of photography should be appreciated if not understood but they should not be something that hampers one’s ability to express thoughts and emotions. It’s just like knowing what characteristics a brush has to the point that it’s second nature to you so that you end up painting rather than trying to figure out the brush and getting stuck in such thoughts.

The Aperture

Jargon often alienates people because it means saying something fancy though it can be said more simply. One of the best examples here is the word “aperture,” one of the pillars of photography. Some people refer to it more simply as an opening and that’s really good because apertures are nothing more than openings. It may be big, small or something in between. The main thing to remember here is that the bigger an opening is physically, the more light it lets through. In terms of shooting photos, it can mean other things but the most commonly known effect is on depth of field – another example of jargon.

Depth of field is nothing more than what is in focus in front of and behind a subject. Imagine a shot of a person. When you shoot a photo, the most important part that should be in focus will be the eyes.

The question is whether you want as much detail on the nose, the arms and whatever may be in front of the person. Another question tied to this how much will be or do you want to be in focus behind the subject. Some people know how to compute for this with relative precision but suffice it to say that there will be more in focus behind whatever it is you actually focus on. If you take the whole area from in front of the subject to behind it, the whole expanse of focus will be divided this way: two-fifths in front of the point of focus and three fifths behind. (Please refer to the illustration)

You can control how much that whole expanse is by means of the aperture. The smaller the opening is, physically, the more there will be in focus. The bigger it is, the less in focus. Now, here’s the kicker: Big numbers indicate small openings and smaller numbers indicate bigger openings. That’s where a good part of the confusion comes.

Here are the traditional aperture numbers, referred to as f-numbers or f-stops: 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22 are 32. There are other f-numbers (reaching even 90 indicating a really small hole) but most of us are 35mm DSLR/SLR or point-and-shoot shooters and these are the more common numbers we encounter. There are also in-between numbers but we’ll stick with these for the moment.

It would really be good if you memorize these numbers. Really. There’s a trick here if you’re not afraid of Math (which is really not that hard as long as the nerds get off their ivory towers and explain things more simply): Each alternate number is twice its predecessor and half its successor. Notice: 1.4x2=2.8 and 2.8x2=5.6 and 5.6x2=11.2 (okay, it’s not an exact 11 but if you round off, you do get the 11) and 11x2=22. Logically then, the number after 32 will be around 44. It’s actually 45 – close enough. If we look at the other set of numbers, 2x2=4, 4x2=8, 8x2=16, 16x2=32. All you have to remember is that these numbers alternate. Just remember the 1.4 and the 2 and you can just compute along the way.

These aperture values indicate either twice the amount of light getting to your film or half of it. Let’s get that straight: If you move from an aperture of 1.4 to 2, you’re effectively cutting the amount of light by half. If you move further to 2.8, you cut that amount of light by half again. So, backtracking, moving from 1.4 to 2.8 means a light reduction resulting in just one-fourth the original amount of light since one-half of one-half is one-fourth.

Let’s get this straight before we leave it:

What about the other way around? It’s actually just the same said backwards. If we start from the other end, from an aperture of 22, for example, moving to 16 means doubling the amount of light. Another step (or properly “stop”) to 11 means doubling the amount of light again. What this means is that going from 22 to, say, 5.6, means increasing the amount of light by 16 times.

Will most photographers talk to you about increasing the amount of light by 256 times? Probably not but you do have to know what’s going on.

Okay, things are getting a bit heavy now. We’ll stop here for now and continue next week.

For feedback, suggestions and things you want tackled, please email me at ericklirios@gmail.com.