I've tried a couple of times to use tone mapping and have found the tutorials quite confusing or deficient (maybe it's just me, a distinct possibility, I'm a bit of a luddite).
If anyone has a link to a decent, well explained tutorial, I'd love to have another goat it.
Hi Andy,
With regards to tonemapping, it's just a process of altering the default brightness of parts of the image. It has a lot to do with enhancing one's vision about which emotions the image should unleash. So,
vision comes first.
Then one can laboriously alter the brightnesses in the image with a plethora of techniques, most of them already built-in in the photoeditor application of choice. So a lot depends on which application one uses. One then selects the tool that achieves the sought after effect (not a filter effect, but the emotional response mentioned earlier) with the least amount of hassle, but with enough control to change one's choices as we iterate closer to the original goal.
In Photoshop, a very effective first step in
local contrast enhancement can be by applying a so-called LoAm-HiRa, an Unsharp Mask filter with low amount (e.g. 10%) but 'high' radius (e.g. 50) setting. One needs to be cautious with potential clipping due to the increased contrast, so working on layers with certain blending mode choices can also make a difference. Modern versions of Photoshop allow to alter the curves adjustment by dragging in the image, similar to what can be done on Lightroom, thus allowing to change the same selective brightness levels throughout the image. One can also use local dodging and burning to only change smaller areas of the image. Masks can be used to only affect specific regions or colors.
Tonemapping takes time to get it "right". It might also require revisiting earlier choices, and making things more subtle or more pronounced than we initially thought.
Also, what's the technique for selective saturation?
As Sandrine explained, Photoshop has tools for that as well.
Because I like to shoot difficult existing light situations, I often have to resort to bracketed exposures to capture the full range. The challenge that follows is to compress the huge dynamic range into the limited possibilities on screen or in print. My instrument of choice (for the moment, and Windows only) is
SNS-HDR. It gives a lot of control over the global and local contrast enhancement, and allows to do selective saturation adjustment, all in a realtime preview. But it is just a tool, it doesn't replace vision, nor does it check one's taste. It is easy to over-dramatise the result.
Whichever tool one chooses, beware for the "to a hammer, everything looks like a nail" syndrome. These tools are no substitute for taste or vision, they are merely tools to efficiently process the image and enforce the vision.
Cheers,
Bart
