Join Ben Long for an in-depth discussion in this video Pressing the shutter button, part of Photography Foundations: Exposure (part 1).
- It's time to discuss how to press the shutter button on your camera. Now I know that may sound a little patronizing, particularly when I talk like this. But it turns out, that simple button press triggers a fairly complex chain of events. And you need to be aware of those events when you press the shutter button. If you're not, if you press the button in the wrong way, you could miss shots, or end up with images with bad exposure. In the days of all-manual photography, before you took a shot, you framed your shot, then you focused, then you dialed in your exposure settings, and it was only after doing all of those things, that you pressed the shutter button to take the picture.
You still have to do all those things, but the good news is that your camera can probably do them for you, and it probably does a very good job. The way you start that process, is to press the shutter button down halfway. If you take a moment now, to feel your shutter button, and I mean feel what happens when you press it, you'll find that there is a halfway point, part way down. A little stop that you can feel. When you press to that point, you're telling the camera to start working on all of those decisions that need to be made before it can shoot.
The first decision is auto-focus. When I press halfway, my camera's auto-focus mechanism springs into action and calculates focus. When it finds it, a light meter in my camera measures the light in the scene and calculates what it thinks would be appropriate exposure parameters. Somewhere in there, the camera is also calculating something called white balance and is charging up the image sensor to make it light sensitive. All that's a fair amount of work and it can actually take some time, especially if you're trying to focus in low light, but once the camera has made all of those decisions, it will beep at you (camera beeps) and possibly flash a little light in the viewfinder.
This lets you know that all of the necessary preparation is done and that you're ready to shoot. I am still holding the button down halfway, so now, if I press the shutter button the rest of the way, the camera takes the shot. It is absolutely critical that you always half-press, hold there, wait until the camera says it's ready, and then press the rest of the way. If you just mash the shutter button down all the way, the odds are you're going to miss your shot because your camera has to chug through all of those steps, before it can take the picture. It's much faster chugging through those steps than you would be if you were doing them yourself, but it still takes some time for your camera to do all that stuff.
Also, as you'll learn, after you take that half-press, the camera's going to report its meter readings to you and you need to evaluate those. If you've experienced the problem of trying to capture a particular moment and you've pressed the button and the camera didn't take the picture when you thought it was going to, that's probably because you mashed the button all the way down. So, if you're not already used to this process that I'm describing, then you need to start practicing it. Because this half-press step is critical to working your camera correctly.
Note: This course is designed to work with any digital camera, but it is easier to follow along using a digital SLR or mirrorless camera.
- What is exposure?
- Modern camera anatomy
- Shutter, aperture, and ISO
- Light metering
- Changing shutter speed and aperture
- Exposure compensation
- Light meters