At various times in this space, we’ve covered best practices when shooting in Automatic, plus making use of Aperture and Shutter Priority, and how to use Program Mode. We’ve also seen how each of these choices can be either very limiting (Automatic), liberating (Priority modes), or even a bit frustrating (Program). From time to time, you’re going to either want, or need, more control than those other options will give you; shooting in Manual, while it can be a bit intimidating, gives you all the control you could want over your camera’s settings.
Here, you’re controlling every facet of exposure. As previously discussed, these consist at a bare minimum of aperture (how much light hits your sensor), shutter (how long it hits) and ISO (how “hard” it hits; that is, your sensor’s sensitivity to light).
Entire books have been written just on the subject of exposure, and while we’ll be revisiting that subject from time to time,* for today, I’ll be going over just enough of the basics to encourage you to try this on your own. Next week, I’ll give you another technique that photographers have used for years that can take some of the guesswork out of getting the right exposure.
For now, however, there’s one very simple tool we’ll be using, which is your camera’s exposure meter. The meter is going to measure the amount of light in the scene, typically using one of three methods:
• Spot Metering: This takes a very small sample of the frame, and meters the whole scene based on that. It comes in handy when you’ve got a scene where one element is much lighter or darker than the rest and you want to retain detail in that part of the frame.
• Center Weighted: Here, the meter’s concentrating on the center of the frame. If you want to meter something off-center while using center-weighted metering, put your subject in the center of the frame, lock your exposure and then reframe the shot.
• Matrix: Here, rather than choosing a spot in one part or another of the scene, whatever you’re seeing in your viewfinder is being metered and averaged. Until you’ve got the hang of the other metering modes, Matrix metering** tends to be reliable.
The caveat here, of course, is not only that each of the metering modes acts differently than the others, but also that they’ll act differently in different lighting situations. When you want to expose something properly that’s either much lighter or much darker than its surroundings, you may find that the meter has either ignored that bit altogether, or metered it to perfection but clipped some other vital part of the scene. You’ll want to practice plenty to get the hang of what each does, so when the time comes for the shots that matter, you’ll be ready.
The meter will also give you a readout in your viewfinder; whether it’s horizontal or vertical, there’ll typically be a “-“ at one end, and a “+” at the other, with a clearly labeled midpoint. That midpoint is usually where you want your indicator to be, since that’s where the correct exposure should be (I say “should” because, as we saw above, you and the meter may not be on the same page when it comes to correct metering of the scene). Going toward either of the extremes means that your photo will be either under- or over-exposed.
This is where your previous experience shooting in Priority modes comes in handy; if you’ve been practicing using the A or S modes (and sometimes the P mode, when it behaves itself), you’ll have already noticed that when you change one value, the other values change with it. The difference here is that instead of changing just one value while the camera chooses the other(s), you’re in complete control, and so you need to be aware that each change you make to your ISO, shutter speed, or aperture needs to balance, or be balanced by, the other variables.
Here’s how the preceding sentence looks in practice. Let’s say that I’m shooting a building in bright sunlight (Figure 1). I don’t need a high ISO because there’s plenty of available light, and since the building is just sitting there, I’m not too worried about stopping a moving subject, so I don’t need a very high shutter speed. However, I would like the entirety of my subject to be in focus, so I’m going to use a small aperture of f/16. So my settings are ISO 400, a 1/400 shutter speed, and an aperture of f/16. If the “needle” is on the plus or minus side, I’d just adjust shutter speed or aperture ’til I had the exposure right, though there are times you’ll want to under/overexpose slightly, whether for practical or artistic reasons.
Now let’s look at Figure 2. As you might be able to tell from the background, it wasn’t quite as bright when this photo was shot. It’s still outdoors, though, so I’m keeping the same 400 ISO. Now I have a choice to make. If I look at the meter using the same settings from Figure 1 as a sort of baseline, it’s telling me it’s pretty seriously underexposed. I can either adjust the shutter speed or the aperture. Since I’m shooting pretty close to my subject and I don’t want it to come out blurry, I’d rather sacrifice depth of field than shutter speed. I settle on the same 1/400 shutter speed, but lower the aperture by a full stop, which leaves me with an exposure that’s right where I want it.
Figure 3 is something else altogether. It’s a chart put together by Ken Storch of Photography Uncapped, showing ISO, aperture, and shutter values in full, half, and third stops. Where this comes in handy is making sense of those numbers, and how each relates to the others. Remember that each full stop (each doubling of shutter speed, ISO, or aperture) lets in twice the light as the one below it, and half that of the one above it. You’re not always going to need that much more light, so you can also increase or decrease by a fraction of a stop. Once you’ve got the hang of that, exposure compensation (which cameras typically display in thirds and full stops) begins to make a hell of a lot more sense as well (thank you, Ken), since there are occasions when changing ISO, shutter, and/or aperture to get the right exposure can give you a perfectly exposed photo that might be precisely the thing you didn’t have in mind. When that happens, you can dial in the appropriate exposure compensation and leave the other settings alone.
This probably sounds like a cursory explanation of a very complicated subject. In truth, it’s a cursory explanation of a subject that makes a heck of a lot more sense when it’s done than when it’s read about. Therefore, my next suggestion has nothing to do with settings, and everything to do with you: do not be afraid of Manual! It’s challenging, true, but it’s also rewarding when you find you’re “getting” it. Practice plenty, and be encouraged by your mistakes, since each of them will bring you one step closer to realizing what’s in your mind’s eye when you press the shutter.
*If you’d like something while you’re waiting, check out Michael Freeman’s excellent – and brief – The Exposure Field Guide (Focal Press)
**This goes by a number of names, depending on the manufacturer; since I’m shooting primarily with a Nikon, I’m using their terminology here. Yet another reason to read the manual.
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