Jodie Coston: Lesson 2

From MorgueFile

Welcome to lesson two!

The next two lessons are going to focus on camera basics. First off, we're going to talk about aperture - also called f-stop - and shutter speed. Those two things alone put me off for a very long time when I was a beginner and considering learning more about photography. All the years I spent growing up while I was young, I had a camera in my hands. I have boxes full of photographs of school events, slumber parties, the poodle I had growing up and all of my friends acting goofy. I figure some of that will make good blackmail material later on in life, but I digress… The point is that I was born with a love for taking pictures, but all of the crazy technical sounding stuff was very scary to me. If that's where you are, I'm here to tell you that you have nothing to be scared of. It takes a while to get the feel of how to know exactly what you're doing, but the basic concepts are quite easy, and I'll give you some tools you can use to help you along until it all comes naturally to you.

This class is designed for anyone interested in learning more about photography. To get the best results from your camera, you should have a camera that you can control manually. By this, I mean you can make the decision on whether to set your shutter speed to 1/60 second or 1/1000 second, as well as control your camera's aperture (which is the hole that lets the light in). If you don't have a camera that will let you control those things, these lessons are a good learning tool anyway to help you know what you might want further down the road to help you create better photographs. We'll talk specifically about film and how it works, but it's completely fine if you use a digital camera. If there's much student interest in digital specifics, possibly we'll touch on that toward the end of the course.

Lesson Two: Aperture And Shutter Speed - How They Work Together

Let's start by studying the following Newtonian lens diagram:

Hah! Are you kidding me? I wouldn't do that to you. I told you in lesson one that I was never any good at math. I took that diagram from a physics book on optics, mostly to emphasize to you that no matter how difficult operating a camera looks, it could always be worse than what I'm going to show you. If at any point you start to get confused, go back and look at this diagram. It will make whatever I'm explaining seem much more simple.

First of all, we'll start out with how a camera works. I assume most of you have the general idea of that already, but in today's world of high-tech-huge-megapixel-super-cameras that do everything but cook your breakfast, it's easy to think that the instruments we use for taking pictures are a lot more complicated than they really are.

Let's look at this:

There are only three things you actually need to make your own camera. Number one is a lightproof box. Number two is something with which you can poke a pinhole in it. Number three is a piece of film to put across the back of the box, opposite the pinhole.

I know that you're probably looking at that diagram and thinking, "What are you talking about? A camera has to have a lens, right? What about a shutter and all that other neat stuff?" Nope. None of that is necessary. Though if you're really going to go the pinhole camera route, you might also need some tape and glue and cardboard and other stuff. The pinhole camera is the most basic of cameras, so I'm basically going to be using it as our model while we talk about apertures. We'll get into the different kinds of lenses and how they work in the next lesson.

Your camera's aperture is the hole that lets the light in. In this case, it's the pinhole. Whatever camera you are using has something called an Iris Diaphragm, which makes the aperture bigger or smaller to let more or less light in. It looks something like this:

Your camera's aperture does two things. First, since we know that it controls the amount of light let into the camera, it stands to reason that it also controls how dark or light your picture is going to be. The second thing it does is control how much of your picture is in focus. This is referred to as "depth of field", which we'll also discuss in our lens lesson.

F-Stops And Amount Of Light

Your camera's lens will have settings called "f-stops" that look like this:

F/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32.

What do those numbers mean?

Those numbers tell you how large the opening of your aperture is. Each of these f-stops lets in twice the amount of light as the next f-stop. I know that it seems a little weird that the smaller number lets in more light than the larger number, but there's a reason for that. It's a ratio, sort of like when we talked about "golden mean" ratios in lesson one. When you buy a camera lens (assuming its not a zoom lens), it will have a number on it that says something like 200mm. That number, simply put, is the distance from the film in the camera to the lens when the camera is focused at infinity. It's called your lens' focal length. There are exceptions - BUT - I'm doing my best to keep on track and just talk about aperture, so let's skip all of the crazy lens technicalities until lesson three. The f-number is the ratio of that focal length divided by the diameter of the aperture (how wide the hole is).

To put all of that gobbledygook that I said above simply, when the aperture of a 200mm lens (focal length) is 50 mm (aperture opening) wide, your f-stop will be f/4, because the ratio of 200/50 equals four. If you "stop down" your aperture to half that size - 25 mm wide - your f-stop will be f/8. (Because its 200 divided by 25.) So the "f-number" gets larger as you let less light in.

If you're feeling confused, go back and look at the Newtonian lens diagram again. Then come back and read this part again. It'll seem like a piece of cake.

Here's what happens when I take a picture under the same lighting conditions, using the same shutter speed, just changing the camera's aperture one stop at a time. Rollover image

I suggest going out and trying this yourself at the end of the lesson, to really get a feel for it.

Shutter Speed And Amount Of Light

Your camera's shutter is the tool that you use to control the amount of time that you let light reach your film.

Following are typical shutter speeds on a camera:

1 second
1/2 second
1/4 second
1/8 second
1/15 second
1/30 second
1/60 second
1/125 second
1/500 second
1/1000 second

Some cameras will have shutter speeds as long as two, four or eight seconds or as short as 1/2000 or 1/4000 second. Two other options you may have on your camera are "T" or "B", which stand for "Time" and "Bulb", respectively. They're basically the same thing and they give you the option to leave your shutter open for as many seconds, minutes or hours as you'd like.

If you set your camera's shutter speed to 1 second, obviously it will let in more light than if you set it for _ second. Basically, light is going to hit your film for twice the amount of time. Each setting is twice as long as the next. So between opening and closing your aperture and varying your shutter speed, you have a great amount of control over the exposure of your photograph.

What you want to achieve is a proper exposure - when the whites in your photo are really white, but still have detail or texture to them, and the dark colors to be really dark, also still showing texture and detail.

In the example above where I was talking about apertures, I used a 1/60 second exposure for each separate photograph. If I had used a 1/1000 second exposure, the f/2 example would have been very close to properly exposed, while f/8 through f/32 would all have been very near completely dark. Conversely, if I had used a 1/8 shutter speed, the f/32 example would have been the closest to properly exposed, while f/2 through f/8 would have been almost completely white.

In the following chart, each scenario will let the same amount of light into the camera - they will each give you the same exposure. Let's say that we want to take a photo using the first scenario of aperture f/11 and 1/15 second shutter speed. If you "stop down" your aperture to f/8, this lets in half the amount of light as f/11, so you'll need to double the amount of time the shutter is open to 1/30.

Aperture (F-Stop) Versus Shutter Speed in Seconds
	Scenario 1	Scenario 2	Scenario 3	Scenario 4	Scenario 5	Scenario 6
Less Light >>	f/11	f/8	f/5.6	f/4	f/2.8	f/2	<< More Light
More Light >>	1/15	1/30	1/60	1/125	1/250	1/500	<< Less Light

Just remember that every time you open your camera's aperture by one f-stop, you're letting in twice the amount of light, meaning that you need to cut your shutter speed in half. Conversely, if you stop your aperture down by one f-stop, you'll be letting in half the amount of light, meaning you need to double your shutter speed time to let the same amount of light in. The two work hand in hand to control your exposure.

Note that the chart above is only an example. You won't go out into the real world and expect an aperture of f/11 to give you the perfect exposure with a shutter speed of 1/15 second every time. In a dark room you'll need much more light than if you're outside on a sunny day.

It's like learning to drive a car with a manual transmission - you need to let the clutch out as you give the car gas or things won't work right. I remember driving around the same block in my neighborhood for two hours when I was 16 years old and killing the car's motor at the same stop sign every single time until I got it right. Using your aperture and shutter speed is the same sort of thing. You'll find as you experiment with the settings, you'll get the feel for them and one day it will just come naturally.

The Other Factor Of Shutter Speed: Motion

Shutter speed can have a really interesting effect when you want to emphasize motion. Look at the following two photographs:

This photograph was taken of this truck with a shutter speed of 1/1000 second. I purposely waited until a vehicle came by with some lettering on it to emphasize how a quick shutter speed stops motion. You really can't even tell whether the truck is parked on the road or moving. In actuality, the truck was moving close to 70 miles (112 kilometers) per hour per hour.

This photo was taken with a shutter speed of 1/30 second. The vehicle was moving about the same speed as the vehicle in the above photograph. This photo definitely implies motion. The longer the shutter speed, the more motion a moving object in your photo will have. Notice that because the camera was not moving and was on a tripod, everything else in the photo is tack sharp.

Finally, this photo was taken with a shutter speed of 1/8 second. Even more motion blur.

Two interesting things to note are that an object moving from one side of your frame to the other will show more motion blur than an object moving toward or away from you. Also, the closer the subject, the more effect your slow shutter speed will have.

One other interesting way to use a slow shutter speed is to photograph a waterfall, or any kind of moving water. I'm sure you've all seen beautiful images of tranquil settings where falling water looks like angel hair moving over rocks. This is accomplished by slowing down your shutter speed. The slower the better for images like this. One thing to note if you're going to try this kind of shot: water reflects a LOT of light - much more than you'd imagine. Even with your aperture stopped all the way down to it's smallest position, it might be too bright for you to get a long enough shutter speed to achieve this effect. Here are two tips. First, these kinds of pictures work best on very dark, overcast days. So if you want to go out and take scenic pictures some day and you're discouraged by the weather, don't be! Just head for the nearest wooded area with moving water. Days like that will really bring out the beautiful saturated colors in foliage, whether it's the vivid greens of spring or bright autumn reds, yellows and oranges, and you'll definitely have better luck shooting water, too. Second, we'll do a special lesson that will include camera filters and what they do, but I think now is an appropriate time to talk about a "neutral-density" filter. This is a filter that is optically clear, but will darken your image to let you use slower shutter speeds. Different filter manufacturers call them different things, but they generally are made to reduce the amount of light getting into your camera by either one, two or three stops. And if that's not enough for you, they can be stacked on top of one another. If you're interested in getting one for your camera, you can go down to your local camera store and show them your camera - they'll help you find one that fits your camera model.

This photo was taken with a shutter speed of 1/15 second - the longest exposure I could manage that day without overexposing my photograph. If I would have had my neutral density filter with me, I could have lengthened that exposure time and gotten an even softer effect with the water, while keeping the rocks and foliage sharp.

So we've seen the difference between fast and slow shutter speeds and interesting effects you can create with your slower shutter speeds. What about fast shutter speeds? The stopped-motion truck in the example above is not every interesting. When would you use a fast shutter speed to your advantage? Fast shutter speeds work really well capturing things that our eyes are too slow to see clearly.

Quick shutter speeds, meaning 1/500 second or faster, are often used in sports photography, whether to capture a high jumper mid-air at a track and field event or to capture a motocross competitor flying high over a jump with bits of mud flying out from under his tires. Whereas the truck in the example above was sitting on the ground, if you catch something in the air with a fast shutter speed, there's no question of whether it's moving or not.

Here again, water can also make an interesting subject. Our eyes don't have a chance to focus on water drops spraying when they hit the shore at the beach, so capturing that kind of event on film can make a really impressive photograph.

This image was taken with a 1/1000 shutter speed to capture the spray of the water off of the apple. It can take a lot of experimenting to get a shot like this right, but it's fun when you finally do.

Along the same lines, this was done by setting my camera on its tripod, setting the focus to a specific spot on the bowl of milk, and simultaneously dropping a strawberry while tripping the camera's shutter. I needed to use my camera's flash - you can see the shadow created by the splashing milk - to get a fast enough shutter speed.

And there you have shutter speed and how it works with your camera's aperture. In the next lesson on lenses, we'll explore other effects of your camera's aperture on your photographs.

Okay, on to the assignments for lesson two:

Assignment 1: Take a landscape photograph using each available aperture on your camera, while using a 1/60 second shutter speed for each shot, similar to what I've done in the example in this lesson. If you don't have a tripod, you can set your camera on a fence post or any other handy thing to keep it in the same place for each shot.

Assignment 2: Do the same thing again, and this time find the shutter speed where your camera's mid-range aperture gives you the best exposure, with nothing being too light or too dark. For example, if you have 9 f-stops available on your camera, your first shot should be nearly white, the last one should be nearly black, and the fifth (middle) one should be nearly properly exposed. If your first assignment came out that way with the 1/60 shutter speed I suggested, try the same thing with a different shutter speed. The idea of this assignment is that the more you do this and fiddle back and forth with these tools, you'll get much more familiar with them.

You don't need to submit these images to me - they're more to give you a feel of how much light the various aperture settings on your camera let in and how shutter speed works with it.

One quick note on these two assignments - if you're shooting digital, you'll do just fine. If you have a film camera, make sure and use slide (transparency) film. Print (negative) film is an entirely different animal - we'll cover film extensively in lesson four, but you should know that when negative film is printed, there is a ton of latitude in how you can expose it. I once took some night shots of the sky and left the shutter open for hours to get a photo of the stars moving through the sky, and the came back looking like they were taken in the middle of the day. The printers tend to compensate for any mistakes you make, and in my case, their automatic printing machine just "thought" I had underexposed my photograph, so it compensated for it. If you try these assignments with print film, most likely you'll wind up with a series of photographs that all come back to you looking the same.

Assignment 3: Go out and take some pictures using shutter speed - either fast or slow - to create an effect. Be creative and have fun!

E-mail me a link to your best shot or two at classroom@morguefile.com. A link from the assignment's discussion forum is always appropriate, too, if you don't mind other students seeing your work or getting a public critique. I actually prefer the second way through the forums - that way you're all learning from each other's assignments, but completely understand if you prefer private critique via e-mail.

Click here to discuss this lesson and post your work in the morguefile forums .

All materials are copyright Jodie Coston 2009-2010.
Sponsored by Jodie Coston, the MorgueFile.com and its contributors.

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Jodie Coston: Lesson 2

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