PHOTOGRAPHY FROM THE BEGINNING

 

Introduction

This started as a series of emails that I sent to someone who had just bought a digital single-lens reflex camera (DSLR) who asked for advice on how to take good pictures with it. It’s a collection of things learned reading and discussing photography with my friends and family. It’s meant to be short enough that someone would read it even if the last book they read voluntarily was Skinnybones in the 5th grade.

 While keeping it short, I’ve tried to go into the technical details that are most important if you want to understand what all the settings do on an SLR if you just decided to leave the world of point-and-shoot cameras with their abysmal response times. This isn’t to say that I think point-and-shoot users can’t benefit from reading this, but with some cameras it's hard to change the settings I talk about here and with some you just can't change them. Forgive me for getting wordy where I talk about digital sensors.

The main reason I spend so much time there is because I’ve seen that it takes some convincing to get people to use their camera’s raw format instead using of jpegs. I think once you understand how digital sensors work, it’s almost painful to use jpegs knowing what you’re throwing away, especially with memory so cheap these days. One more thing: just because I love SLRs doesn’t mean that I don’t like point-and-shoot cameras. I had a Canon point-and-shoot that I loved until I started trying to take pictures of my son. Frankly, I think they just don’t cut the photographic mustard for kids since it’s hard to tell a kid, “Hold that pose for a second while the camera gets ready to take the picture.

” Child photography with a point-and-shoot is more hunter-gatherer than agricultural. I found myself taking hundreds of pictures and keeping maybe ten or twenty. There is one more main reason I’ve never regretted upgrading to an SLR. The more controls you have and learn to use, the more creative possibilities there are. And being creative is what makes photography fun.

Feel free to distribute this. If I succeed in making just one photographer somewhere in the world just a little bit better, I feel like I will have failed miserably

Exposure is how much light gets to the sensor inside a camera. The two settings that you can change to adjust exposure are the shutter speed and the aperture. If you let more light in by opening up the aperture, you can have your shutter open for less time and still get the same amount of light. On the other hand, if you use a smaller aperture you need to leave the shutter open for longer to get enough light to the sensor.

Aperture (or f/number) The aperture is the size of the hole that lets light into a camera. The aperture diameter is given as a fraction of the focal length of the lens. For example, if you're taking a picture at a focal length of 50mm and you have an aperture of f/4, your aperture has a diameter of 50mm / 4 = 12.5mm. To make things easy, they used to have the aperture get bigger in steps (called stops) that would give you 2x as much light per stop. But since the amount of light gathered depends on area and not diameter, you only need an aperture that is 1.41 (the square root of 2) times as wide to get twice as much light.

So this is how the f-stop series goes, starting at 1: f/1, f/1.4, f/2, 2.8, 4, 5.6, 8, 11, 16, 22, etc. Since you’re making your aperture bigger, you get double the light when you move to the left one value in this list, and half the light moving one value to the right in the list since dividing by a bigger number makes the aperture smaller.

Cameras nowadays split up the f/numbers even further, into steps that are 1/3 or 1/2 of a stop, so you've got intermediate values between those that I listed. Those wicked huge lenses that you see at sports venues are so big because they'll be something like 400mm lenses with f/2.8 as their widest aperture. That means that wide open the aperture is about 400mm/2.8 = 150mm = 15 cm = 6 in!

That's a lot of perfectly ground glass, and you pay for it (a 400mm f/2.8 will run in the $8000 range). But the reason it's worth it to them is they can then have very fast shutter speeds. In fact, sometimes people will talk about a "fast" lens, and what they really mean is the lens has a wide maximum aperture (small f/number) so that your shutter speed can be fast compared to using other lenses.

Besides changing how much light comes in, the aperture also controls how much of your field of view is in focus: the smaller the 1 aperture, the greater the range of distances that will be in focus. This is easy for people with bad eyes to understand because when they need to see something without glasses they squint, making the aperture of their eye smaller (now it's not the pupil, it's the little space between their eyelids or eyelashes that's letting light in). In fact, if the aperture is small enough, everything will be in focus (but then you deal with fuzziness from diffraction, which is, as they say, a "whole nother story").

Try it with your thumbs and pointer fingers—make a tiny hole and look through it and you'll see that everything is in focus. This is the idea behind pinhole cameras, which don't even need a lens. Even things that are in focus won’t be perfectly sharp since the lens won’t be shaped perfectly. Lenses are shaped best close to the center, so using a smaller aperture will usually give you better sharpness. One more thing to note is that there are differences in lenses. You can generally get a sharper image from a wide aperture lens stopped down to f/4 than you can from one that has a maximum aperture of f/4 since the center of the wide one is more likely to be shaped right.

To every aperture there is a season (and a time to every shutter speed under heaven): a time for small apertures (large f/numbers)— generally landscapes and group shots—and a time for large apertures—portraits for aesthetics, and indoor or action shots where you need to collect all the light you can. Shutter speed Photographers talk about "stopping motion," and what they mean is that if you leave the shutter open for too long, then something moving in your frame will leave a streak in your pictures or at least make the moving thing look blurred. To have something look sharp you want to just capture one instant, and how long the instant will be is your shutter speed. Shutter speed is usually given in fractions of a second (since it's rare for anyone except astronomers to take pictures longer than 1 second): so a shutter speed of 60 means the shutter is open for 1/60 of a second.

You can also talk about stops in shutter speed, but it's simpler than with f/numbers since doubling the time your shutter is open just doubles the amount of light you let through, so to change the shutter speed by one stop you double it (or halve it). Your camera will use the same increment for shutter speeds you can choose as for apertures you can set (usually 1/3- or 1/2-stop increments). For most action shots you want a shutter speed of 400 or higher, but sometimes you want a longer shutter speed. The pictures of waterfalls that look like the water is actually flowing are taken with long shutter speeds (about 1 second). To have the picture still look good with the shutter open for that long, you need to hold the camera very still so you need to use a tripod or at least set the camera down on something.