Hampton Green, Arbroath
Many of us have tried blending two exposures in Photoshop, one biased towards the highlights and the other the shadows, with varying degrees of success in my own case. HDR takes this a step further. It's best to have the camera on a tripod as the images have to be in perfect register to ensure sharpest results. The greater the range of tones in the scene, the more exposures should be taken. Three are OK but sometimes five-even more-are better. The bracketing should span at least two stops above and below the "normal" exposure and it's best to leave the aperture alone and adjust the shutter speed. The darkest file should look almost black and the lightest almost white. It's possible, I believe, to blend these together in Photoshop CS3 but I only have CS and I've consequently never tried it. Instead, I used Photomatix which does the job very quickly and easily.
Cafe Marmaris, Arbroath
Two things have to be done with the bracketed exposures. First, these have to be loaded into the software so that an HDR file can be generated. Then the resultant file has to be "tone mapped" which is a way of simulating the appearance of a high dynamic range on computer monitors that are just not capable of displaying true HDR. Tone mapping sort of squeezes the HDR file to match the contrast range of the average monitor. The effect, depending on the various settings used for tone mapping, can range from the quite natural to the Disneyesque.
The Boatyard Cafe, Arbroath Harbour
If we can forget for one moment that these images started off as "photographs" and just consider them as art, then I like them a lot. They have a charm about them and a cartoony quality that appeals to me. Printed on nice paper and framed, they'd look good hanging on the wall. In some cases, I definitely prefer them to photographs of the same scene. Interior shots with bright light streaming in through the windows look great.
The biggest drawback in my admittedly limited experience is the unpredictability of the process. Sometimes I'm certain that the scene in front of me will look stunning in HDR only to be disappointed at how dull it emerges from Photomatix. At other times, I've taken photographs of quite ordinary subjects just to see how they will look and been very pleasantly surprised. However, the seemingly arbitrary nature of HDR is also one of its plus-points as you never know what you're going to end up with. I'm finding HDR quite interesting and will be doing some experimentation in the weeks ahead. I want to change the white balance of the files and also might work on their contrast before they're merged into an HDR file for tone mapping.
The shots in this post were all taken with the K10D and the 16-45mm zoom. Since the camera was on a tripod, I used 100 ISO as there wasn't a lot to be gained from anything faster. I think I've written before that the 16-45 lens is a cracker and it gets even better when the camera is tripod-mounted. There's a little bit of distortion that's correctable with software but sharpness, contrast and flare resistance are of a high order. I really can't see any difference between the results I get from the zoom and those from the 21mm DA prime. Maybe if I peered really hard at the two files I'd notice something superior about the 21mm but let's just say that it isn't apparent in everyday shooting.
Now, with my photographer's hat back on, I have to say that I partly agree with critics who say that an HDR image isn't a "real" photograph: it's more like a photography-based graphic image. It might also turn out to be little more than a gimmick. In a year's time, we might all be looking back at HDR the same way we now view all those Cokin filtered and black and white infrared shots that once looked quite innovative. Or even worse, the way we now look at the flares, kipper ties and butterfly collars of the 1970s...