Pet Projects. Part 1.

What's wrong with this picture?

Medfield State Hospital, Building D1, 16 April 2012
Nothing really.

I've had a couple of pet projects occupying my time in the past few months. One of them is High Dynamic Range (HDR) photography.

The brightness range of an image from its darkest shadows to its brightest highlights is the image's dynamic range. The human eye can see an almost infinite dynamic range. Photographic technology has a (very) limited range.

As a practical matter this means is that one simply can't have a photograph with details in both the shadows and the highlights at the same time. A photograph can have one or the other, not both.

Photographers generally expose the scene for what it is they want to emphasize in their final image. Is the "subject" in the shadows? Overexpose. Is the "subject" in the highlights? Underexpose. It can be a little more complicated than that but that's basically the technique for managing limited dynamic range.

So here.

This is normally exposed
You can't see much detail in the shadows under the porch roof. And at the same time you can't see much detail in the paint peeling off the columns.

This is overexposed (by 1 f stop)
You can see more details in the shadows here but the highlights are completely "blown out". You can't see any lines delineating the bricks or the slate tiles on the roof. And the porch roof line isn't that white.

This is underexposed (by 1 f stop)
You can see some detail in the highlights, the lines delineating the bricks on the wall and tiles on the roof. The peeling paint along the porch roof line. But the shadow detail under the porch roof is gone. The shadows are basically ... just black.

Now, the business of HDR photography is digitally combining these 3 different images into a single image that captures more range than is possible with the single image. It's like saying take the first image as...the image, and take the shadows from the second image, and take the highlights from the third image.

I have not been at all impressed with the "digital darkroom". I've mostly shrugged it off. Of course I crop my pictures. And I tweak them often. Adjust the exposure here and there and do a little retouching ok, but I've found it's more about economics than it is creativity. I can't do anything (that I want to do) with Photoshop that I couldn't do in a darkroom.

But this is something different. I think. This really does have the potential for artistic expression. The final images will have high contrast (which is mostly undesireable) and, in the image above, I deliberately got heavy handed with it to make a point. The subject has a surreal quality to begin with so I think even given its heavy handedness it kind of works.

Now it's more about finding the best subjects for HDR photographs and applying a light enough hand to have the observer thinking "now that's a beautiful picture" rather than "what's wrong with that picture".

Here's a great tutorial on creating HDR images with some free software which is a great way to learn more.