Raw Processing and Sensor Dynamic Range

The Olympus OM-D EM-5 mirrorless camera that I have had now for about a year is at the high end of the Olympus Micro 4/3 line and sports an excellent 16 megapixel sensor. But the megapixel count is not what makes this camera special. It is the excellent dynamic range and low noise. Here’s an example of what I am talking about. It’s a scene with very high contrast. The sky is much brighter than the foreground rocks. If you expose for the sky the rocks go completely dark and if you expose for the rocks the sky gets blown out.

Olympus EM-5 Raw file converted directly from the camera using lightroom.

Olympus EM-5 Raw file converted directly from the camera using Adobe Lightroom.

The image was exposed for somewhere in the middle of the sky and the foreground rocks. The sky lacks detail and the foreground is dull. But starting with a raw file it is possible use Adobe Lightroom (or Adobe Camera Raw) to tame the highlights and pull better detail and tonal quality of the dark areas.

Here is a screenshot of the basic adjustments I applied in Lightroom.

Screen Shot 2013-05-18 at 8.05.01 AM

The “Highlights” slider is pulled all the way down to tame the sky and the “Shadows” slider is pushed all the way up. This yields a rather flat image so far, but the detail in the sky and the foreground are retained. Then I push up the “Whites” slider a bit, which brightens it up without pushing the highlights too far. Lowering the “Blacks” slider adds a little more contrast.

Finally, the “Clarity” and “Vibrance” adjustments give the local contrast and color a boost. Here is the result:

Edited image converted out of Lightroom.

Edited image converted out of Lightroom.

Note that even though I’ve pushed the darker areas up a great deal and then added local contrast boost, there still is very little noise, even looking at the full size image on my monitor.

Now this image still can use some tweaking. I can do some additional fine-tuning in Photoshop. But I have a much better image to work with than trying to go straight into Photoshop/Elements (or even Lightroom) with an out of the camera .jpg file.

Of course, these adjustments need to be done with care to meet the needs of every specific image. It might be argued that my clarity setting is too high. The thing to remember is that if you don’t like the result, you can always go back and adjust.

Lightroom is a great tool but equally important is the “material” you are going to use the tool on. In this case, starting with a raw file allows you to get the most out of the camera’s sensor. For me, this allows me to use the smaller Micro 4/3 cameras, which are so much lighter than the full-sized DSLR, and still get excellent image quality.

~ by Admin2 on May 18, 2013.

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