talino.org » black & white

Realistic HDR tonemapping

Tal — Wed, 24 Oct 2007 21:39:17 +0000

Lately I’ve spent some time experimenting with HDR tonemapping using Photomatix Pro and Photoshop. I find that most examples you bump into on the web demonstrate the ability of tonemapping to create very striking and surreal images. But actual benefit of this technique, in my opinion, is that it allows a photographer to capture a scene exactly the way it looks in real life. Granted, it is very gratifying to use tonemapping’s dynamic range compression to manipulate light in a creative manner, with results like the photograph above. What seems like an infrared shot of a snow-covered park is actually a photograph taken on a sunny day which presented lots of variations between lights and darks. Different exposures were assembled into an HDR image which was subsequently tonemapped. The resulting 16-bit image then went through some funky monochrome channel mixing in Photoshop.

However, it is interesting to see what happens when you use tonemapping in a more discreet fashion. With everyday subjects and settings, it is possible to obtain images which otherwise could not have been captured but which do not present that “in your face” effect. For a low-resolution medium (such as a web page), you can get by with bracketing the exposure using fast continuous-shooting mode and keep the camera handheld. If people don’t move too much, the artifacts associated with HDR misalignment are reduced to a minimum. This results in ordinary-looking photographs which correspond a lot more to the scene as it was originally framed in the viewfinder. The following images illustrate the point.

Train and train station

Tal — Thu, 26 Jul 2007 00:32:11 +0000

Two shots taken during a recent trip to the south of France.

Experiment with stark lighting

Tal — Mon, 20 Nov 2006 17:29:22 +0000

A black & white shoot, with direct sunlight and a black drape. Many thanks to Virginie H.

Girl on a movie set

Tal — Mon, 20 Nov 2006 16:37:47 +0000

The image on the left is an attempt to create a CG version of the photograph on the right.

The background is a 3d model created from scratch. The woman is a Poser figure. The elements were composed in Photoshop and retouched. The two images above are two renders of the environment from different angles.

Brazil version

This is the same model, except it was rendered with Brazil r/s. Only one self-illuminating object behind the wall, compared to the 7 spotlights in the scanline render. The grain this time is from the renderer, not from Photoshop. It could have been smoother, but 3.5 hours rendering time was more than enough. Anyway, considering that I didn’t even think of using Brazil until later, I think I got pretty close with the original image.

Girl on a window

Tal — Mon, 20 Nov 2006 16:20:15 +0000

The image on the left is an attempt to create a CG version of the photograph on the right.

It is a composite of different layers and techniques: The window and the shoe are a 3d model created from scratch (I’d forgotten Poser had shoes…) The background is also a 3d model. The woman is a Poser figure. All three elements were composed in Photoshop. The hair and the bottom of the dress were heavily retouched, since the Poser render was quite atrocious.

The images above are two slightly fetishist renders of the window from different angles.