Exposure

This is where we start to put things together...

ISO 200 | 0.5 seconds | f/29

ISO 200 | 0.5 seconds | f/29

A good exposure is all about balance

Notice that every single photograph in this slideshow has the same tonal balance - meaning one image is not really any lighter, nor is it any darker than the others, aside from the variable of shooting in natural light, that is.

What changes is how the water looks visually from one photograph to the next.

In each photograph's exposure-formula, the ISO remained constant at 200, while the Shutter-Speed and Aperture values are the ones that change. A long Shutter-Speed is equally balanced with an Aperture which throttles down on light, and vice versa.

Arriving at a good exposure is not hard, here's one way to do it…

Creatively, we already see the photograph in our imagination before we even think of picking up a camera. So use that imaginary-picture to guide your actions.

Set the ISO first, then set the property which has the most impact for your photograph. Finally, set the remaining value to bring your exposure into balance.

That's it, a very simple step-by-step process.

With this waterfall, I set to ISO 200. (This was because I was doing this particular example, otherwise I would have gone with ISO 100.) Since, I like blurred-motion, a low ISO is usually the way to go, and so is setting a long Shutter-Speed next.

Which Shutter-Speed do I set to? I don't know yet. I do know from experience that a Shutter-Speed value in the 1/2-second to 2-second range, will usually deliver the best results, but not always. (I'll start somewhere in that range and judge the results when I finally take the photograph.)

Finally, the last remaining property is the Aperture, so I will set that to whatever brings the exposure-formula into balance.

This formula, and all the different property values, are always subject to change should I need to increase or decrease the light. Every situation is different, so the exact formula we use one day, probably won't work with others, but following this workflow will get us in the ballpark.

So yeah, that's it. That's the big secret to obtaining a good exposure: ISO first, then select the property that holds the biggest impact for your photograph, then set the final property to bring the formula into balance.

From there, it's simply a matter of fine-tuning the formula to our liking. Of course, it's not always as simple as that, especially if you are in natural light, but that's a good workflow to build on.

On my cameras, I have an LCD display for my light-meter (next page) so I will be consulting that as I adjust that last remaining property.

I will review my settings and if I like what I see, take the picture.

Typical mobile apps will only allow for the camera's control of the ISO and Shutter-Speed, not the Aperture.

This is referred to as a Shutter-Priority mode. The user sets the ISO and Shutter-Speed, then the camera sets the Aperture value for us.

Other cameras also feature an Aperture-Priority  mode, where we set the ISO and Aperture, and the camera sets the Shutter-Speed. I often shoot in Aperture-Priority mode.

Okay, so I've just taken my photograph and now it's time to look at what the camera has recorded. If I am shooting film, I have to wait for the film to be developed into prints (or transparent slides) before I can see the results.

With digital, it's instantaneous. Another big plus for digital cameras.

If your camera offers a histogram (next page), use that to see how an image stacks up (literally). If not, use your camera's LCD display.

If I'm satisfied with that, THEN I will look at the image on the display to see how the water looks visually.

Here is where, if necessary, I fine-tune my exposure-formula until the photograph looks the way I want.

If I adjust the Shutter-Speed (from say 1/2 of a second to 1 full second) to show more of a motion-blur, I am allowing 1 full-stop more light to come through and hit the film/sensor.

So to keep my exposure in balance, I must now close down the Aperture in equal measure (1 full-stop). Otherwise my tonal balance will be thrown off and I will end up with a much brighter photograph.

"To photograph is to hold one's breath, when all faculties converge to capture fleeting reality. It's at that precise moment that mastering an image becomes a great physical and intellectual joy."

Henri Cartier-Bresson

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