XtremeCamera

A primer on Shutter Speed, Aperture, and the Program mode.

A properly exposed photograph will only occur when the scales of photographic justice are equally balanced. It matters not what aperture you choose, what shutter speed you choose, it matters only that whatever you do to one you must balance with the other. Just as you cannot violate the laws of physics you cannot violate the laws of photographic justice.

Okay, so maybe I’ve taken some liberties here with the whole ‘photographic justice’ angle, but today I’d like to write a primer for all the members here at XtremeCamera, and those non-members that happen by each day and who may not have a solid grasp on how to use the aperture and shutter speed on their camera. Stay with me here and you might walk away with one huge ‘Eureka’ moment.

The Whole Scales Of Photographic Justice Thing

Balance is key to many things in the universe. It is especially key to good photography. Without striking a balance on the SPJ (Scales of Photographic Justice) your photographs will be either under-exposed or over-exposed.

On the one side of the SPJ is Aperture; on the other is Shutter Speed. Here’s how the laws of physics apply to SPJ.

It’s All About Light

Photography is possible because of light. Light reaches the film plane (or CMOS sensor) and controlling the amount of light is only half the equation in getting a properly exposed photograph. The quality of that light is the second half of the equation. Aperture and Shutter Speed control the quality of the light, as well as the amount of light.

Example: (Aperture)

Your loveable mutt Mr. Jangles desperately wants his picture taken. This is obviously the case since he walked up to you, camera strap in your mouth, and he kept nudging you. So you decide to appease Mr. Jangles and shoot a portrait.

You pick up the camera, remove the lens cap, turn it on, and point it at Mr. Jangles mug. You properly compose the image, making sure to not clip his ears in the in-camera crop. Since you always keep your camera set to ‘P’, or Program mode, you click the shutter button and you’re done. You look at the photo in your camera’s LCD and you think the same thing you always think; “Its okay I guess. But boy I spent a lot of money on this thing. You’d think it would take better pictures. I mean seriously, his nose is sharp but what’s the deal with his eyes? Why are his eyes blurry? I need a better camera. Oh honey!”

Wait. What?

Let’s back up…

First of all, it’s nice that your dog wants his picture taken, but you know as well as I do that dogs are big hams away. They LOVE having their picture taken. And of course it’s nice that you want to take his picture. You want Mr. Jangles to feel good about himself, don’t you?

So, if you want a good picture and Mr. Jangles wants a good picture, why in the world do you keep your camera on Program mode? Chances are its one of two reasons; one, you want to shoot fast, or two, you’ve decided that the thousand dollar dSLR knows more about how to expose that picture than you do.
If you really want a good picture of your dog you owe it to yourself, as well as Mr. Jangles, to learn how to use those pesky Aperture and Shutter Speed doohickeys.

Balancing The Scales

Here’s all you need to know, for now, about Aperture…

If you are creating a laser beam weapon you know that the tighter the beam the more powerful the weapon. A tightly focused laser beam will cut through a lot of stuff; a poorly focused laser beam is basically a lamp.

The Aperture on your camera lens works the same way. When you shoot wide open, meaning you’re using the largest aperture setting, like f1.4, f1.8, f2, f2.8, etc, you’re letting in the most light. Its not tightly focused. When you stop down your aperture, like f5.6, f8, f11, f16, etc, you are focusing that light coming into the camera.

The law of physics is such that there is a direct relation between the focus of that light to the space directly in front of your object of focus, and behind the subject of focus, and the tighter the focus of light the more focal range you have. Don’t ask me why, it just does.

If you wanted Mr. Jangles entire head to be in sharp focus you needed to stop down your aperture enough so that the focal range was long enough to include not only the tip of the nose, but his eyes and his ears. When you think Aperture think Focal Range.

The Camera Doesn’t Know Best

Unbeknownst to you that pesky camera of yours decided to focus on the tip of your dogs nose. It also decided for you that because you’re indoors, because the only light in the room is coming from a lamp on the table, that the ‘best’ setting is something like 1/125 shutter speed (a standard setting for stopping most motion) so the camera had no choice other than to balance the scales (as it is programmed to do) and open the aperture up to a wide f2.8. The result is an ‘okay’ picture, but nothing to brag about. And those beautiful eyes of Mr. Jangles went soft in the photo, a huge injustice to the dog, but your camera doesn’t care.

Understanding the SPJ you would probably make decisions about the Aperture and Shutter Speed that are much different than your cameras decisions.

Shutter Speed

Like the aperture, shutter speed also controls the amount of light. In the SPJ it’s just as important as aperture and when they are balanced your exposure is correct. As a matter of fact, the built in light meter inside your camera is programmed to alert you when the SPJ as balanced or not balanced, and if not balanced it will show you how much and whether or not there is too little (under exposure) light reaching the film plane or too much (over exposure).

But, if both aperture and shutter speed had the same characteristics it would be redundant to have both doing the same job.

The shutter speed is used differently than the aperture. Instead of focusing the light coming into the camera it slices the light up. The slower the shutter the more light, but also the more slices of the moment. The faster the shutter the less slices of the moment.
These so-called slices of the moment allow you to isolate the movements in the scene. If your subject is moving quickly, say Mr. Jangles jumping in the air to catch a ball, you will want a tiny slice of the moment to reach your film plane. The tinier the slice the more isolated the moment, so that slice becomes clear, sharp, and crisp.The more slices you let in the less sharp it will be.

It is accepted, again the physics stuff, that for most everyday motion, walking, talking, etc, a shutter speed of 1/125th of a second will take a small enough slice of the moment so that it looks sharp. Anything faster and you’re going to need a more isolated slice of the moment. Anything slower and you don’t need to worry much about the number of ‘moment slices’ you capture on your film plane.

When you are photographing a house, a barn, a tree, or a parked car you can use a shutter speed as slow as you want it to be. If your camera is on a tripod you can slow it down even more. Handholding a camera is steady to about 1/60th of a second for most people. Any slower and you probably need a tripod, unless you’re a surgeon, those suckers can handhold a camera with a shutter speed of 1/10 of a second. You see, it’s not only the subject that moves, its you as well.

Putting The Scales To Use

In the case of Mr. Jangles you could use a slow shutter speed if your dog is being really still, otherwise you’re going to need 1/125th. Or you’re going to have to move somewhere that is better lit, or add some light with a flash. In any case, the scales must be balanced.

Here are two examples you can think about that explain the aperture and shutter speed in action. By the time you reach the end of the second example that ‘eureka’ moment I mentioned above should go off in your head and you will be forever free of the dreaded Program mode and you’ll be able to increase the creative control over your photos by an order of magnitude. Honestly. I wouldn’t lie.

Example #1 (Shutter Speed)

You decide to grab your camera and head outside for a walk. Before you left you also decided to switch that dSLR off of Program and on to “Manual”. Today you have total control. Sure, you’re scared and all, but this is going to be good for you.
About a mile down the road you happen across a very old barn sitting in a meadow of yellow flowers. You decide this will be your first picture taken completely manually, save for you built in light meter and auto focus lens of course.

You frame your shot in your viewfinder, so far so good. Thinking about that elusive ‘rule of thirds’ you have the barn where you want it and you’re about to click the shutter…until you remember you need to set the aperture and shutter speed. Uh oh!

First, let’s think shutter speed. You glance around the viewfinder and you notice that the yellow flowers are not moving, nor are the trees to the left and right. Good, no need to capture many slices of the moment. You think, “No movement means I can spend all my light capital on the aperture. I can handhold at 1/60th of a second, so that’s what I will use.”

Good, good, you made a decision. And it’s a good one as long as you can really be steady at 1/60, and there is truly no wind to worry about. Using 1/60th of a second means that there is going to be a whole lot of light coming into the camera so adjustments must be made to the aperture.

You decide to put all this SPJ to the test, as you should. With your eye still in the viewfinder window you glance down and see the light meter. You read that the camera’s aperture is currently set to f2.8 and the meter is telling you “Whoa! Too much too much! This is going to be way over exposed!”

You gently turn the aperture knob with your left hand while staying focused on your light meter. One click smaller to f3.5 and the needle on your meter moves closer to the middle. Still over exposed though so you click again. And again. You wind up with f16, and the needle is dead center. The scale is balanced; your exposure will be good. Now think.

“F16 means that the light is tightly focused, which means that the focal range is long, which means that only will the barn be focused but so will those yellow flowers in the foreground, and the trees in the background.”

Is that what you want? Well, okay then. Click the shutter. You’ve created your very first manually shot photograph.

But you’re not done. You’re learning, so keeping the shutter speed where it is adjust your aperture smaller and larger and click the shutter each time. Never mind that the meter is telling you the photo is going to be over exposed and under exposed. You want to see, on your computer screen, how this whole aperture thing is going to figure in on the whole focal range thing.

(Now, if you are really going for the gold here, do the following: Each time you move the aperture move the shutter speed to compensate. Keep the needle of your light meter in the middle. Moving the aperture one click means having to move the shutter speed one click. Each click is called a “stop”. When you take a series of pictures this way its called “Bracketing”. Bracketing is an excellent way to learn about depth of field.)

Okay, you’re done, lets move on down the road.

Example #2 Shutter Speed

As you continue down the road you happen across a softball game being played in the public park. You decide to try and grab a few shots of the players in action.

You mossy over to the park and find a good spot to shoot from. You settle on the action of the batter. You watch as player after player come to bat, swing away, and head off to the bases. You think that it would be cool to capture a player in mid-swing, freezing the bat in action.

You point your camera at the current batter and you wait. And you think. You remember that the camera is still set at 1/60th and f16. While the f-stop would be fine you know that 1/60th is way to slow to capture the bat in mid-swing. Adjustments must be made.

Thinking about the whole ‘slices of the moment’ thing you remember that the tinier the slice the more isolated the moment. You know that if you want the bat to be sharp you’re going to want to shoot at the fastest shutter available to you, so that you can capture the tiniest slice of them moment, providing of course that your aperture can be set to compensate.

You decide that in order to freeze the bat in mid-swing you will need to shoot at 1/2000th of a second. You set the shutter speed and the meter tells you that if you leave your aperture at f16 the shot is going to be under exposed. So you move the aperture back. One click to f11, still under exposed. One more time to f8, better, but still under exposed. Once more to f5.6 and presto, the needle is in the middle and your shot will be properly exposed.

All you need now is to wait for the batter to swing… Eventually he does and you click away. After a few batters have come up to bat and swung away you realize you took half a dozen shots. Now back away and review your shots in the LCD display. You see that you actually got a few good shots and the bat is frozen in mid-air and its sharp. Excellent, you just created some action shots using your manual settings.

But, you’re not done yet. Do the Bracketing thing again. Shoot more batters in mid-swing, but this time slow your shutter speed down one by one until you get to that magic 1/125th, all the while adjusting the aperture as described above. Now you’re done. When you get back home and look at those shots you will see that the more you slowed down the shutter the more slices of the moment got into the shot, and the bat became more and more blurry because those moments overlapped on the film plane.
Now, honestly, wasn’t that easier than you thought it would be?

What Did We Learn Today?

Well, a lot actually. We learned that you don’t need the Program mode to make good photographs. In fact, Manual is really the creative mode for photographers. Manual lets YOU decide what the photo will look like, not your camera.

We also learned that your aperture is used to control the focal range. A smaller f-stop, which means a larger number, (f16 is smaller than f2.8) will increase your focal range, not by magic but rather by physics. The light entering your lens at f16 is akin to a stronger laser beam. The larger the aperture (f2.8 is larger than f16) the less focal range because the light is less tightly focused. The wider aperture means that your focal range will be shorter. Again, physics is your friend.

We learned that shutter speed controls the number of slices of the moment that you are going to allow to reach the film plane. You want to freeze fast action so you need to allow a tiny slice of the moment to reach your film plane, or CMOS sensor. The less movement in the photo means it matters not whether you allow more slices of the moment to reach the film plane because all those slices of the moment are pretty much identical. Those slices of the moment overlap each other, but because they are all the same it doesn’t matter.

Finally, we learned that by effectively using both your aperture and your shutter speed you make the decisions about how many slices of the moment will reach your camera and how large your focal range will be.

Knowing this stuff, understanding this stuff, will free you from the horrors of Program mode. If you really want to be able to control your photographs you need to keep your camera on Manual mode for at least the next couple of months. Never, ever, take it off Manual until it becomes second nature, until you can evaluate a scene and tell the people next to you, “If I were photographing this I would use f16 at 1/60th of a second. Yep, I would.”
Unfortunately, when this stuff sinks in you will forever evaluate all the scenes you see in terms of aperture and shutter speed. No, no you won’t, I’m kidding. But you will for a while. Yea, you really will.

Not to confuse you or anything, but here’s a few quick tips for you to use AFTER Manual settings are second nature to you…

Aperture Priority (A on your camera settings) means that YOU choose the aperture and your camera will choose the best shutter speed.

Shutter Priority (S on your camera) means YOU choose the shutter speed the camera chooses the f-stop.

And there you have it. If you’ve paid attention, and if you head out and try this stuff as I laid out you will be free of Program mode forever. Program mode is for those that want to take pictures without thinking about them. It’s the way camera makers sell thousand dollars cameras to non-photographers.

If you call yourself a photographer, whether it be an amateur (someone that does not make a living with their camera) or a professional (someone that does make a living from there camera), you do not want to use Program mode, ever. Its just frowned upon. It means you’re lazy, or that you are a beginner. And if you’re a beginner and you want to learn about composition first, then fine, leave it on Program mode for a while. If you’re lazy chances are you haven’t read this far anyway.

Leave Program mode to the beginners. Take control and be creative. Become a real photographer.

Thank you for reading. I look forward to hearing about your experiences after you’ve tried these methods I laid out.

Oh, and next time we meet we’ll talk about film speed, or ISO, and how it too works with aperture and shutter speed. Wise use of ISO extends the reach of your f-stops and your shutter speeds, but you need to know all about ISO before you even try to use it effectively. I promise, I’ll tell you all about it very soon.

John Manzione
OnSite Admin

Note* Scales of Photographic Justice and Slices of the Moment are copyrighted 2008 by John Manzione. Unauthorized use of these phrases is prohibited by law.