Taking process pictures on the job or in the shop
There’s something about photography that’s related to carpentry, I just can’t quite put my shutter finger on it. But I know a lot of photographers who are carpenters. I think it has something to do with using tools. After all, a camera is just another tool: in order to use one, you have to know how it works.
If you’re one of those carpenters who has an interest in photography, but you spend most of your energy mastering techniques for your “day job,” this article may be of use to you—in your own work, your website, for personal photographs, or if you want to write an article for Fine Homebuilding, JLC, or THISisCarpentry. You can’t invite hundreds of readers or potential clients to your job site. Having good photographs is the best way to communicate the quality of your craftsmanship. For that, a camera is just another tool!
How Cameras Work
Photography is all about light.
A camera is really just a lens with some film behind it. Today we use digital “film,” but it’s still treated as if it’s film. When you open the lens, light—and that means the scene in front of the lens (which is made up of different shades of light)—is recorded on the film. Magic. I don’t understand that part, and you don’t have to either, any more than you need to know how to build an electric motor for your miter saw. All you really need to know is how to control the saw—how to make a butt cut, a miter, and a bevel.
A camera is a tool for capturing light, and you can control light in three ways:
1. The size of the lens opening
2. The amount of time the lens is open
3. The sensitivity of the “film”
1. Aperture: The Lens Opening Size
Imagine the lens on a camera is like your eye: When it’s bright outside, you squint; when it’s dark, you open your eyes up wide. That’s how you let more light or less light into your eye.
A camera lens works the same way. If it’s bright and you want to let in less light, you close down the lens until it’s just a pinhole. Conversely, when it’s dark, you open the lens up wide, which allows more light to hit the film.
The size of the lens opening is called the aperture, or f-stop. That’s easy, huh? Too easy. To make it more difficult, the industry sizes aperture openings in reverse of common sense; but if you’re into shotguns or electrical wire, you’ll take to this system quickly: small aperture openings (think SQUINT) are around f-16. Wide aperture openings are around f-5.6.
2. Shutter Speed: The Length of Time
Taking a picture is like stopping time—at least, it’s as close as we can get to doing it. In the nineteenth century, photographers used to control time by removing the lens cap then replacing it. Of course, they weren’t able to do that very quickly (plus the film wasn’t very sensitive!), so people had to stand very still for long periods of time because of the slow shutter speed.
Today we can take really fast photographs—in fact, we can stop water from a faucet; we can stop a ball coming off your kid’s baseball bat.
We stop time with a camera by opening the lens (or lens shutter) and closing it really quickly—in a fraction of a second. If the lens is open a long time, more light goes through. If the lens is open for a short period of time, less light goes through. That’s how you control the amount of light that reaches the film, by changing the amount of time the shutter on the lens is open.
3. Film Sensivity
The third way we control light is by changing the sensitivity of the “film.” Before digital cameras, we had to change the actual roll of film in the camera for darker scenes, but today all we have to do is push a button: the ISO button.
Increasing the ISO number increases the sensitivity of the film. For shooting outdoors, an ISO number of 100 to 200 usually works well. For shooting indoors, an ISO number of 600 works much better. Some cameras can take good pictures even at ISO 2000 and higher—almost in total darkness.
The ISO setting may be the most important adjustment you make before taking a picture, especially if you’re taking photographs inside a shop or jobsite. Remember, photography is all about light. If you don’t have enough light to read by, you’ll need to increase the sensitivity of your film…that’s the ISO number!
Read the full article by Gary Katz on www.thisiscarpentry.com