Why Manual Exposure is Critical to Your Photography

That's 1/100th sec @ f4, ISO 50. A manual exposure, no frills attached. (Copyright 2011 / Andrew Boyd)

That's 1/100th sec @ f4, ISO 50. A manual exposure, no frills attached. (Copyright 2011 / Andrew Boyd)

THE BACK STORY

After a few days of fairly intensive shooting, I found myself thinking once again about how important mastery of manual exposure is to the photography that I do. While I love the auto features that come on my DSLRs, knowing when to use them and when to turn them off is at the top of my list of things that novice shooters need to learn. Here’s why:

Depending upon the camera to make your exposure choices for you is a safe, but dumb, way to work. You’ll usually get an acceptable exposure using this approach, but you’ll rarely get the best photograph. Why? Because the camera measures light and makes a calculation for you, but the camera has no aesthetic understanding of what you’re shooting. The camera can’t know if you need the background sharp or out of focus; the camera can’t know the optimal shutter speed for the image you’re creating. Only YOU know that. Here’s an example:

CASE STUDY

I’m photographing a wild rose blossoming right off my back porch. In the first version, I’ve set my DSLR on ‘Program’ mode. Program mode calculates a correct shutter speed AND aperture for the light that it’s reading. It decides to shoot this photo at 1/200th sec @ f5.0.

A wild rose shot using 'Program' mode, in which the camera takes a light reading and chooses its own aperture and shutter speed. (Copyright 2011 / Andrew Boyd)

A wild rose shot using 'Program' mode, in which the camera takes a light reading and chooses its own aperture and shutter speed. (Copyright 2011 / Andrew Boyd)

But this isn’t what I wanted. I want the rose blossom to be sharp, in focus, drawing your eye to that point in the image. I want the background out of focus to emphasize the rose blossom. So I switch to manual, and open the aperture to its widest point. Then I simply dial in the corresponding, higher shutter speed. My exposure in this case becomes 1/1250th @ f2.8.

Now with the lens aperture wide open at f2.8, I can focus the photograph on the rose petals and throw the rest of the shot out of focus. (Copyright 2011 / Andrew Boyd)

Now with the lens aperture wide open at f2.8, I can focus the photograph on the rose petals and throw the rest of the shot out of focus. (Copyright 2011 / Andrew Boyd)

The focus of the photograph now becomes the rose petals, with the other bulb out of focus and no longer a point of competing interest.

By using the power of manual exposure to create the image I want, I control my result and I get the image that I wanted in the first place.

Note:  ‘Aperture Priority’ mode and ‘Shutter Priority’ mode – in which you either set the aperture or shutter speed and the camera picks the other variable—can be useful, but are still limiting. The minute you choose one of those modes, something will happen in front of you that requires a different solution.

So: if you haven’t made the effort to learn the ins and outs of manual exposure, what better time than now?  It will add new depth and understanding to your photography and become the basis for a lifetime of pleasurable shooting.

Hi, I’m Andrew Boyd, a.k.a. The Discerning Photographer, and I hope this post has been interesting and informative. Please leave me a comment about it, let me know what you’d like to see more of on the site! You can also sign up for email delivery of all future articles or my RSS feed. Thanks!–DiscerningPhotog

Posted in: How To

About the Author:

Photographer, videographer and photo editor. Host and creator of The Discerning Photographer web site. Currently a Canon shooter.

6 Comments on "Why Manual Exposure is Critical to Your Photography"

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  1. Bayou Bill says:

    A very, very, subtle, but very worthwhile, difference, imho.

    At first I thought I liked the Program Mode exposure better, because slightly more petals were within focus range. But when I imagined how this photo would look blown up to print size, I realized that the Program Mode focus drew the eye away from the primary subject (the blossom) because the stem and undeveloped bud were “almost in focus”, so I decided I like the manual focus version better.

    But I would have still liked to get more of the rear petals in focus. Is there any way to do this without also drawing in the stem and bud?

  2. Konstantin says:

    Andrew,

    Thanks for the post!

    And how would you know what’s the “corresponding higher shutter speed”? So the image is exposed right? Do you look at the exposure level indicator? And how is it then different from using P or Av/Tv modes?

  3. Thanks for the question, Bayou Bill. The answer is yes: the other big factor here is focal length. I shot this with a 50mm macro, although the closeup was not a big part of the composition. A longer focal length–even 70mm on my 70-200–would have thrown more of the background out of focus. I would probably shoot several focus variations to get what you’re suggesting. Also, within depth of field, an old trick that really works is: focus 1/3 of the way into the things you want in focus, then stop down. That’s the best overall spot for maximum depth of focus.

  4. Using the built-in light meter, I dialed my shutter speed until it hit the magic number for correct exposure, after having set the aperture. That’s the beauty of manual exposure, you’re in complete control.

  5. Hammed says:

    So how’s that different from setting the camera to aperture priority and have it choose the shutter speed?

  6. You could do that , Hammed. But I’d still not be satisfied. Here’s why: when you choose ‘aperture priority’ or ‘shutter priority,’ you’re locking yourself into a aperture/shutter relationship. What happens when you decide you want a different relationship? Maybe 1/2 stop darker or brighter. Then, I’d have to go back out and make a ‘+/-‘ adjustment to the global setup to achieve this….for me anyway, it’s just easier and more in line with my thought process to go whole-hog manual much of the time.

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