Dynamic Range For Photographers

July 22, 2017  •  Leave a Comment


Dynamic Range...

I get asked every now and then by budding photographers: "How do I make my camera take pictures like...."

When pressed they sometimes show me an image where it's either too dark or too light. Most of the time images are shot on a SmartPhone and occasionally an expensive camera. Why doesn't it take pictures that matches what they see through the viewfinder or on the LCD Screen. A perfectly good question but not so easily answered in a way that won't make their eyes gloss over as I explain. I've narrowed it down like this..Dynamic Range (for photographers) is the difference between the lightest and darkest area of a scene, such as a landscape. Our eyes are exceptionally good at "seeing", even the best cameras can't match them (yet). At the heart of a typical camera is a computer system stored with representations of many various scenes. In the instant it takes to frame, focus and press the shutter button it compares them against your composition and chooses what "it" thinks is the best way to capture the image.

The better cameras get it right more often than not but a challenging scene such as a dark foreground and bright background will almost always trip them up. As you get more comfortable with a camera you can "change" it's mind by making creative choices as to how you want the scene captured.

Rowing on The Bow RiverRowing on The Bow RiverBanff, AB

Fig. 2

In Fig. 2 above I was faced with a heavily back-lit scene. If I exposed for the foreground the background will be over-exposed (too bright). Exposing for the brightest areas of the image will render the foreground underexposed (too dark). Left to it's own devices  no pun intended) a camera will always try to pick a middle point which is ok for a snapshot but I have higher standards. This is where camera choice becomes critical. I exposed for the brightest part of the scene (bright sky) knowing that my camera had enough Dynamic Range to capture enough detail in the dark areas. In this case I was using a Fujifilm X-Pro2.

Rowing on The Bow RiverRowing on The Bow RiverBanff, AB

Fig. 3

Once I got home and loaded the RAW file into Adobe Lightroom CC, I raised the exposure level of the shadow areas in order to balance out the scene. This was exactly the way my eyes saw this composition..with a little bit of creative license here and there. Not all cameras are this capable in that regard so your mileage will vary.

Banff National ParkBanff National ParkLeigh Miller | www.leighmiller.ca

Fig. 4

Fig. 4 above is what I call a "one-shot-wonder" capture. It was mid-afternoon in Banff, Alberta and the sun was hot and in full-on shine. Typically I would employ a Neutral Density Filter (graduated) in order to tame the exposure of the sky. This time though I captured the entire scene with a slight amount of clipping in the highlights and selectively edited the exposure in Adobe Lightroom. It's not a perfect capture but I saved myself a whole lot of time and effort in getting it. I wasn't there specifically to shoot landscapes...in fact, I was in the middle of having lunch. Call it...a shot of opportunity.

The reason you can't do this as effectively with an image from a SmartPhone is because of the tiny sensors they contain. They simply do not have the kind of dynamic range essential to capturing images in difficult situations. That's not to say that you can't make great images with a SmartPhone...get creative. Shoot at a different time of day when the lighting is less harsh or employ it's HDR function.


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