Getting Started with Photography

Please excuse any typos or grammatical issues. I just typed this in one sitting and haven't proofread it. This is part one. I'll wait for questions and write the second, and last part, then. This replaces the much shorter, kind of half-assed post that used to be here.

Section A

Like most art forms there are two components to photography: the technical part and the aesthetic part. Traditionally with any art form a great deal of time is spent on the rudiments before anything of merit can be produced: a lot of piano practice and theoretical study is required before playing or composing a complex piece. Sculpture, painting – they're all the same in this respect: people generally learn the craft before getting good at creating art because the technical stuff is such a barrier to entry. Learn the basics and the barrier goes away – suddenly your trombone stops making farty noises and you can really learn to play. Until quite recently this was true of photography – because you had a limited number of shots on a roll of film (typically 24) and it took time and money to see the results it made sense to do a bit of homework so that you wouldn't get 23 dark or blurry shots back.

With the advent of digital cameras there's a trend towards reversing this order. Because you can pretty much take a camera out of its box, turn it on, point it, and get a picture, in my experience most people buy nice cameras and never learn how to photograph. I'm a firm believer in learning the (very simple) basics of photography first. And the way I'm going to explain it requires you take a lot of test shots to make sure you understand what I'm talking about. As you do this you're going to be stretching your aesthetic muscles without even realizing it.

Bottom line: if you and another equally proficient person pick up identical cameras and use them for a month (you following this document and the other guy just mucking about) you will be a dramatically better photographer than the other guy. I guarantee it.

Ok. There are three components in every camera: The lens, the shutter, and the film (or image sensor.) I'm going to explain in as much detail as you'll probably ever need how each component works, and then how they work together. As you progress through all of this make sure you have a camera handy to experiment with. The more you shoot the faster you learn. And as daunting as this may seem once you “get it” it's all really simple, and you need to know it if you want to be a good photographer.

The three camera parts operate in very simple, predictable ways. I'll start by explaining each component.
Lenses are actually made up of two components: the glass part which focuses and zooms, and the aperture, which limits the light which passes through the lens. First let's figure out the lens part.

Lenses are described by their focal length, measured in millimeters. The longer the focal length the higher the magnification, and the magnification increases linearly, or proportionally to the focal length. This means that a 100mm lens provides twice the magnification of a 50mm lens, and a 200mm lens provides 4 times the magnification of a 50mm, and so on. The focal length is derived from the diameter of a theoretical glass sphere. Take a 50mm glass sphere and slice a piece off, any piece. It doesn't matter if you cut it in half or take a tiny contact lens slice. The resulting piece of glass (flat on one side and curved on the other) is a 50mm lens and they will all have the same magnifying power. But a simple lens like this is prone to all kinds of optical errors and flaws so camera lenses use multiple glass elements which, when added together, both eliminate many of the flaws and result in the same magnification as the simple single element lens.

Prime lenses have fixed focal lengths. They don't zoom, but the images they produce are generally of a much higher quality, certainly dollar for dollar. So a prime lens is described by its focal length: a single number like 50mm or 35mm. On a typical DSLR a 35mm lens will produce a field of view that's about as wide as what you see with your naked eye. Zoom lenses are described by the minimum and maximum focal lengths, like 70-210mm or 24-70mm. These lenses can operate at any focal length between the first and second numbers. Beware the incredibly wide range lenses like 20-300mm. While it might seem like this one lens can do a lot there's generally a tradeoff in quality. Professional photographers (if they use zooms at all – I rarely do for reasons I'll get into later) generally have 3 zooms, roughly: 18-35mm, 24-70mm, and 70-210mm.

Each one is engineered for optimal image quality over its range, something which can't be said for the tempting 20-300mm cheapie.

Lenses all have a focus ring which can be set manually or automatically. Auto focus allows you to pick some high contrast picture element and let the camera do the focusing for you. It doesn't matter. If you dial in “5 meters” and stand 5 meters from a tree, the tree will be in focus just as if you let the camera do it for you.

Sometimes it's difficult to find something to focus on so manual focus will be your only option. This differs from camera to camera and playing around with it is the only way to know when to switch to manual focus. For the time being stick to auto. There's more to focus which I'll get into when I explain how this all fits together.

Lenses all have apertures at the camera side of the lens housing. An aperture is like the pupil in your eye – it's a (roughly) circular opening that can change size from small to large. Obviously the bigger the opening the more light gets through, and vice versa. The way the aperture is measured is a bit tricky but worth understanding. Short form: it's precisely the opposite of what you would think.

The aperture size is measure in f-stops. The f-stop is derived by taking the focal length and dividing by the actual diameter of the size of the opening. Because the opening is the denominator the bigger the f-stop the smaller the aperture, and vice versa. This is very important: f/22 is tiny, and f/2.8 is huge. It will take a little while to get used to this so just keep in mind that, with aperture, small is big and big is small.

If you think about this for a second you'll realize that the actual size of the aperture opening to let through a specific amount of light for a 50mm lens is smaller than the size required for a 100mm lens. This is why the formula includes the focal length. F/2.8 on a 50mm lens lets exactly the same amount of light through as f/2.8 on a 100mm lens, but the opening on the 100mm lens is twice as large as on the 50mm. F-stops allow you to forget about the focal length because they are universal.

Another tricky thing is the fact that, in a zoom lens, the aperture opening size for f/2.8 at 24mm is a lot smaller than the size of f/2.8 at 70mm. A lot of clever engineering is required to make a zoom lens that can open up to f/2.8 all the way from its shortest to longest focal lengths. Such lenses exist but they are expensive. Typically a cheaper zoom can't open up as wide at the longest range, so these zooms are described with both minimum and maximum focal lengths, and the maximum aperture at each end of the focal range, like 70-210mm f/4.5-5.6. This means you can open up the aperture to 4.5 when it's zoomed all the way out, but only to 5.6 (which is smaller, remember?) when you zoom in. Zoom halfway in and the maximum aperture will be somewhere between 4.5 and 5.6.

Why the weird f-stop numbers? Why not easier numbers like 2, 3, and 4? There's actually no reason other than convention and one other thing: each f-stop results in precisely half (or double) the amount of light passing through. Many lenses have half or even quarter stops you can dial in but here is a list of full stops. Compare these to what your lens can do.

1 1.4 2 2.8 4 5.6 8 11 16 22 32 ….

You may notice that these numbers correspond to 1/sqrt(2)^0, 1/sqrt(2)^1, etc.

Some lenses will have f-stops in between these numbers (most will, actually.) And you don't need to memorize these full-stops, although you will end up knowing them anyway. 1.4 lets in twice as much light as 1. 4 lets in half as much light as 5.6. It's pretty simple, and it doesn't matter what lens you use. F/4 is f/4 is f/4.

So you've got a lens that can focus light onto a plane that sits somewhere behind the back of the lens. This light passes through the lens elements, through the aperture, and hits what used to be a piece of film but is now a digital sensor. This sensor is designed to require a specific amount of light in order to produce a properly exposed image. More on sensors in a moment, because before the light passes through the lens and hits the sensor it has to get past the shutter.


Section B

The shutter is pretty straightforward. While it's a bit more complicated than this, you can think of it as a flap that is totally opaque, covering the sensor. It slides up, allowing light from the lens to hit the sensor, and then down again. While it's down the sensor sits in complete darkness – the only light the sensor receives gets there while the shutter is open.

We know that a specific amount of light is required by the sensor in order to produce a photo. And it should be apparent that there are two ways to control how much light hits the lens: the aperture and the shutter speed. In general (assuming in both examples the camera is pointing at the same scene) if the aperture is wide open, like f/2.8, then the shutter only needs to be open for a very short period of time. And if the aperture is closed tightly, like f/22, then the shutter needs to stay open a lot longer to allow sufficient light to hit the sensor.

The shutter speeds on a camera make a lot more sense than f-stops. 1/50, 1/40, 1/30...it's pretty self explanatory what each means. But there's a kind of subtle but enormously important thing to learn here and it requires going back to f-stops for a moment.

Remember how the arbitrary seeming divisions between f-stops are set up so that one stop in each direction allows either half or double the amount of light to pass? This difference in the amount of light is sometimes referred to as a “stop” but it can get confusing for beginners because it's so close to the term “f-stop.” A new term was coined to avoid this confusion: Exposure Value, or EV.

Each f-stop adds (or subtracts) 1 EV of light. Big deal, right? It's just another way of saying what you've already learned. But here's the cool thing that 90% of photographers will never figure out: each shutter speed value does the same thing.

Read that again. It's one of the most important things to understand. If you toggle through the possible shutter speeds you'll see they go from about 1/8000 all the way through 1 second and up to about 30 seconds. But the possible shutter speeds aren't arbitrary – each successive shutter speed allows twice as much (or half as much, depending on if you're getting faster or slower) light as the previous. So f-stops and shutter speeds all add or subtract 1 EV each.

Now read that again. Seriously. And consider the following: Let's imagine that for whatever reason your camera has decided that it wants to use f/4.5 and 1/30 sec for your shot. Let's call the amount of light that hits the sensor X. If you were to close your aperture down by one EV to f/5.6 the shutter would have to stay open longer, to 1/15 sec.

(I can't think of a non-cumbersome way to talk about increasing or decreasing shutter speeds and f-stops so I'm going to use the word “click.” When you dial these values the thumb wheel will click every time you increase the f-stop or increase the shutter speed to the next one along, so when I say “click” I really mean “select the next f-stop or shutter speed value, either up or down, depending. I hope this makes sense.)
To recap: for a given f-stop and a shutter speed it's possible to maintain the same amount of light hitting the sensor in the following way: if you add a click in f-stop you subtract a click in shutter speed. If you go down a click in one you have to go up a click in the other. Make sense?

For obvious reasons this is called reciprocity. Whatever you take away from one you have to add to the other. The good thing is you only need to pick one: either your f-stop or your shutter speed. Most professional photographers choose the aperture and let the camera figure out the shutter speed, and I recommend this, eventually. Forget about every camera setting on that dial and find A (or AV) mode, S (shutter) mode, and M (Manual) mode. These are all you will use. You will never use Auto, or P, or (god forbid) Landscape again.

AV or A mode lets you pick the aperture and the camera measure the light and chooses the appropriate shutter speed. S mode does the opposite – you dial in your shutter speed and the camera sets the appropriate aperture. 6 of one. I almost always use A priority. M mode lets you pick both the shutter speed and the aperture, although when you pick one it does tell what it thinks the other should be. But more on that later.

A quick word about shutter speed and aperture. While the amount of light hitting the sensor is the same whether you have a slow shutter/small aperture combo or a fast shutter/big aperture combo, the resulting photos will not be identical. They will be exposed the same way but will look different in a few potential ways.

The longer the shutter is open the more time moving objects have to change position before it shuts again. So if you're at a racetrack trying to get good clean shots of the horses but your shutter opens for 1/30 of a second the horse (and its legs) will have moved quite a lot in that time. They will be blurry. This might be what you want. But for fast motion a good rule of thumb is that your shutter should be no slower than about 1/250 sec. Obviously because you'll be using A mode you're not going to be picking the shutter speed. But choosing a wide aperture (meaning a low f-number) will result in a faster shutter speed. So if you go to a soccer game set your aperture as low (open) as possible and you'll automatically use the fastest shutter speed. Another thing to bear in mind is that if you aren't using a tripod it's kind of hard to stay totally still for longer than about 1/15 sec. Even if you're taking a picture of a tree it's going to blur because your hands shake at 1/15 sec, at least without practice. Again, open your aperture to get a faster shutter speed.

That's about all you need to know about shutter speed and its effects on the image. What about aperture? It's a bit tricky to visualize this and very easy to see it so I'll see if I can dig up some images. What's important to understand is that when you focus on an object at Z meters away there is a certain distance closer to you than Z and past Z that will also be in focus. For example if you stand across the street from a house and take a shot it's likely that the car parked in the driveway, considerably closer to you than the house, will also be in focus. But if a kid standing 6 inches in front of you photobombs the shot his head will probably be out of focus. This range, a distance in front of and behind the actual focus setting, is known as “depth of field,” abbreviated as DOF. And there's a simple rule: the lower the f-stop (meaning the wider the aperture) the smaller the depth of field. So a portrait shot at f/16 will look fine. But a portrait shot at f/1.4 might have the eyes in focus but the ears blurry. The DOF at very wide apertures can be millimeters.

The final piece of the puzzle is the sensor. Back in the days of film you could purchase stock of various speeds, measured in ASA. If you were shooting in broad daylight ASA 100 (quite slow) would be great. Dusk might require a very fast ASA 3200. The tradeoff was that the faster the film, the grainier the picture. And of course once you stick a roll of ASA 200 film in the camera you are shooting at ASA 200 until you finish the roll.

With digital you are free to change the sensor speed whenever you like. Sensor sensitivity is measured in ISO but the numbers are exactly the same as ASA. And there's the same tradeoff: low ISO means cleaner images but requires more light. High ISO means much less light is required but produces more digital grain, known as noise.

And here's the cool thing. Every time you go up one click on the ISO wheel, which typically means every time you double the ISO, you gain one EV. So the reciprocity I spoke about earlier has a third component: ISO. This means if you go up a click in ISO you can go down a click in either f-stop or shutter speed. Etcetera.

Section C

When your camera points at something and you push the button it measures how much light is needed to properly expose an image. It calculates this based on the ISO setting. Then (if you've chosen the aperture) the camera selects the shutter speed and takes the picture. If you've chosen the shutter speed it picks the aperture and snaps the shot. Manual is a bit different – you need to experiment a bit to see how this works but here's my best shot at an explanation:

In manual you typically have to tap, but not push, the shutter button to tell the camera to take a light reading. Looking through the viewer (or at the LCD) you will see some kind of scale kind of like this:

x....x....0....x....x

The “0” in the middle represents a perfect exposure. As soon as you tap the shutter button you should see a line on this scale which represents how under or over exposed your shot will be based on the current aperture/shutter settings. It will look something like this:

x....x.|..0....x....x

Each “x” (or whatever your camera uses) represents 1 EV, so this image is currently a bit less than 1 EV underexposed. You want it to look like this:

x....x....|....x....x

Figure out which dials control the shutter and aperture settings and try a few clicks in each direction with each one. You'll see that the “|” moves left and right as you click up or down on either dial. And you'll really “get” the reciprocity rule – it's possible to move the “|” to the left with a few clicks of the aperture and back to center again with the same number of clicks in the opposite direction on the shutter wheel. And of course if you double your ISO this will happen:

x....x....0....|....x

The overall exposure of a shot is often referred to as 0 EV if it's properly exposed because the “|” sits right on the middle 0. A shot that's overexposed by 1 f-stop or 1 shutter click has an exposure of +1 EV, meaning the “|” will be to the right of the 0 where the first x is. A shot that's underexposed by 1 f-stop is -1 EV. Not every shot will be perfect at 0 EV. Sometimes things work better over or underexposed, and this is where experience and experimentation comes in.

Congratulations. You've just covered about a year of film school. What do you do with all of this? The first thing I recommend is to purchase a fast 50mm lens, stick it on the camera, and don't take it off for a month. A fast 50 means an f/1.2 if you're rich, an f/1.4 if you're doing fine, and an f/1.7 if you're a student. You can get a nice used f/1.7 in Canon, Nikon, or Sony off Craigslist for under 100 bucks. Spend that money – you won't regret it. The wide aperture will allow you to take beautiful shots with defocused backgrounds as well as razor shot landscapes. And foregoing the zoom will force you to think about where you want to be to take the shot. Zooms are nice but they can lead to laziness, especially when you're starting out. And most kit zooms only open up to 4.5-5.6, so they're useless unless you're shooting in very bright light.

Regardless of whether or not you can buy a fast 50mm, here's what you do next. Learn how to use manual mode as I described above. Then commit to shooting in 4 chunks. Maybe 4 days, or 4 groups of 2 days. I recommend spreading out your 4 chunks into what will fit in a month. If you're using your zoom, don't zoom it – keep it at the shortest (lowest, widest) length possible. And every day you go out pick some simple subject like a car or a flower – something stationary – and shoot it every way you can. Stick to the one subject per day for now. Don't delete any shots and don't fuss too much over what you see on the LCD.

Think about aperture, shutter speed, and DOF. Review all the shots when you get home on a computer, so you can look at the shot and see all of the settings you used to get it.

For the first chunk shoot your subject at every possible aperture. You can use Aperture priority for this.

Then, for chunk 2 shoot your subject at every possible shutter speed. You can use Shutter priority for this.
For chunk 3 shoot in Manual mode, remembering that you want to center that “|” to properly expose a shot.
For chunk 4 try taking a shot at -1 EV, meaning the “|” is left to the first x, then -2 EV. Try overexposing at +1 EV, then +2. See how far you can over or underexpose. Pay close attention to what over and underexposing does to your shots when you review your work on a computer.

source