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Exposure Share This on LinkedIn   Share This on Google   Tweet This   Forward This

6 April 2017

This scene stopped us in our tracks. It was just an old window that seemed to have been a late addition to the building and now was an afterthought, its wooden frame rotting away.

Exposure. An old window frame in the morning.

But the morning sun strafed the stucco and gave it life. We could see the paint drips on the wall, the uneven stucco, the paint chips on the frame, even the dust on the glass in high relief.

It was a quick snapshot which we edited in Capture One Pro, straightening it out first, then cropping out some intruding shadows until just the frame looked back at us. We exported it at this size, so no other photo editing application came into play.


A lot of images go through life untitled but this one was Exposure from the minute we captured it. For three reasons.

The Elements

The first association is certainly with the weathered window. It had been exposed to the elements for 70 years with apparently no maintenance, not even a coat of paint. Which made it a very unusual subject.

This, consequently, is what 70 years looks like. This, in other words, is what survival looks like.

The Settings

The second is just as obvious, at least to a photographer. That would be the settings used to make the exposure. Aperture, shutter speed, ISO. In this case we used f5.4 in Aperture Priority mode, letting the shutter speed run to 1/600 second at ISO 200.

Exposure. The metadata.

Exposure in the digital age is quite a bit different than it was in the film era where the sensitivity of the emulsion was not a variable.

Today, you can set ISO on Auto without much fear of producing noise in the shadows. And you only have to worry about shutter speed if your subject is moving because you can handhold with a high ISO or image stabilization active in the camera or the lens. So aperture can be anything you need to bring as much of the field into focus as you want.

In this case, we didn't have to worry about depth of field at all. There wasn't any to begin with. We could have shot this in Program mode.

The one thing we did have to do was frame the image. The focal length was the equivalent of a 78mm lens on a 35mm system, a moderate telephoto, that cropped the image generously but sufficiently.


The third association takes a little more imagination, let's just say.

We went to the shelves and pulled out The Negative by Ansel Adams, which happens to have a chapter titled Exposure. He was concerned exclusively with film exposure and development for printing but we can read it with slightly different eyes.

It begins with a simple observation that if you expose normally, what you capture "may contain considerable information yet not be adequate for interpretation in terms of an expressive image."

You won't get something you can use if you don't make an exposure that favors your intentions. Making one that the meter suggests is optimal is likely to capture "inadequate information" to produce the image you want.

He tells a funny story about that.

I can recall seeing Edward Weston, who was not particularly of scientific persuasion, using his meter in rather unorthodox ways. He would point it in several directions, take a reading from each and fiddle with the dial with a thoughtful expression. "It says one-quarter second at f32, I'll give one second." His approach was empirical, based on long experience combined with very deep sensitivity and intuition and his extraordinary results speak for themselves.

For Adams, shooting negatives, the game was to produce a printed image. The negative was a medium. He liked to say the negative was the musical score and the print was the performance.

JPEG Version. Uncropped JPEG thumbnail extracted from the Raw capture.

In the digital era, the capture is still the score but the performance is rarely a print. One of the joys of digital photography is being able to edit an image for the screen, which using transmitted light rather than the reflected light of a print can deliver a far more vibrant image.

Getting adequate information from a capture to form that image involves not just the exposure savvy Adams illustrates with his story about Weston (which, as we pointed out above, is a lot easier today) but also recording as many bits as your camera will permit.

In a Raw capture this tends to be 12 or 14 bits per channel (compared to the 16 bits per channel of a scanner, for example). In a JPEG it's just 8 bits per channel.

You can only see what 8 bits per channel can display so you might wonder what all the fuss is about with Raw captures. Just expose accurately and bingo.

But that often delivers no more than the properly exposed negative. An image incapable of expressing anything.

Which 8 bits of the 14 in each channel you show is the trick. So exposure in this sense becomes post processing. That's where you "give one second" in the digital age.


We worked on this image in Capture One Pro to bring out the detail in the stucco and hang on to some texture in the shadowed window pane while maintaining some contrast and color in the faded paint of the window frame.

Curve. Post processing.

And we needed every bit of every channel to do it.

We anchored the midtones before we manipulated the curve to brighten the highlights. We could see the contrast of the wall pop. Then we darkened the shadows slightly until we just barely hung on to the detail in the shadowed glass of the window.

We had a great deal more range to play with than a JPEG would have provided. Take a look at the JPEG thumbnail we extracted from the Raw capture to see what a "properly exposed" image yields. And compare that to our Raw edit at the top.

The result of the Raw edit is an image that shows not just an old window but the harsh beating the sun had given it.

Exposure, in a word.

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