HDR: How To Do It On The Cheap
At this point, you may be thinking, “That’s all well and good for a pro photographer with a mountain of expensive photo gear and a hard drive full of specialty editing software. All I’ve got is a cheap little camera.” Your pessimism might be further confirmed by searching the Internet for HDR resources, practically all of which seem geared toward at least active amateur photographers. Yes, I was skeptical at first, too—still am, for that matter. Frequent Tech Myths readers know that I have a budget of approximately zero. Sure, I’d love to go drop a grand or two on one of the new Pentax dSLRs [digital single-lens reflex cameras] with built-in, three-exposure HDR capabilities, but I won’t. Instead, I’ll make do with my aged 6-megapixel Canon Rebel 300D (the original, not one of the newer ones), available all over eBay for under $300. Like practically all dSLRs, the Rebel offers an auto-exposure bracketing (AEB) mode in which the camera will capture at the stated settings, then one overexposure and one underexposure at up to +/-2 EV settings. Alternatively, you can take more exposures manually. For example, you might set the shutter speed to 1/60 then take a wide range of aperture settings. Some photographers will combine 11 or 13 shots into a single HDR image, although it doesn’t take long for a layman to sense a point of diminishing returns.
Once you have multiple exposures of your scene, you need some HDR software to do the merging and tone mapping. If you have absolutely no budget, I’d recommend starting your quest with either Picturenaut (www.hdrlabs.com/picturenaut) or Qtpfsgui (qtpfsgui.sourceforge.net), sporting a name only a developer could love. But apart from being cheap, I’m also short on time for learning curves. For $99, you can get a license for Photomatix Pro. I’ll spare you from my geeky rants of ecstasy that occurred the first time I used this app. Suffice it to say that I’ve never been this excited about a piece of software before.
What you see here is my very first experiment with Photomatix Pro. I went across the street, sat on the curb, and took a picture of my house (f/18, 1/40 sec., ISO-100). Then I took six other shots at +/- 2/3 EV at each step. Mind you, I did this while bracing my forearms against my knees. The large image on the left shows the optimal EV setting mentioned above. The large image on the right is what Photomatix Pro generated. I didn’t touch a single setting, retouch in Photoshop, or anything else. Personally, I think the tonality is way too pink, and I’d like to see the sky a deeper, richer blue, but that’s easy enough to modify, either by tweaking Photomatix’s settings or with a little color bending in whatever editing software you prefer. But look at the improvement in detail! Compared to the original image, you can now see detail in the front door and inside the arch. Look at how the neighbor’s house goes from nearly black to a very noticeable (and more or less accurate) red. Flowers suddenly jump out of the shadows. And unlike the original, the HDR image reveals that both cars really need washing after our family camping trip. Sometimes, a little less reality is okay, too.