Last night's Rose Bowl fireworks were amazing but smoky. Many times I said to myself, "Boy I'll bet there are some fantastic fireworks going off inside that cloud of smoke." But other times I think the illumination of the smoke created a nice effect, and here's a photograph of one of those times.
Nikon D90, Nikkor 18-105mm @ 26mm, f/18, ISO Lo 0.3 (which is about the same as ISO 170).
The smoke and firework burst is from a 5.3 sec bulbed exposure. Let's call this image A.
To get some detail from the Rose Bowl, I combined 9 separate bulbed exposures from 3.5 to 60 seconds (total of 188 sec) taken about 9 minutes earlier, right after the stadium lights had gone off but before the fireworks had started. I combined these using software that I wrote to produce an OpenEXR image, then in Photoshop I converted to a 16-bit TIFF, but only by adjusting the exposure and gamma settings. This produced image B.
I gradient masked image B so that only the bottom portion (with the stadium and some of the background lights) is used, set the layer opacity of B to 37% and used the "Lighter Color" mode to blend with image A. So about 75% of this image (the top portion) is in fact straight out of the camera.
Is this an HDR? If "HDR" means combining multiple exposures to get more information than you could get from a single exposure, then yes. If "HDR" means tonemapping via an algorithm that locally adjusts the contrast (like Photomatix), then no. But I'm curious to hear your opinion.