The technique involves exposing a range of identically framed shots at shutter speeds calculated to expose for points between the darkest and lightest parts of an image. By default, where an image contains extremes of light and dark, cameras only expose perfectly for a part of the picture, whereas the naked eye is quick enough to compensate for the variations in light reflecting from the various surfaces included in the field of vision. The picture here for example might have been challenging because the sky is much brighter than the tree so a choice for a single exposure would be to expose for the sky, leaving the tree as a silhouette, or to expose for the tree, leaving the sky to be blown out. With HDR I take a range of shots at different shutter speeds and build a composite in software to get the optimal exposures combined in one image.
I’ve used Nik Software’s HDR Pro 2 for these shots, partly because I’m a big fan of Silver Efex Pro, their essential Black & White plug in for Lightroom & Photoshop, and partly because I’m trying to achieve results that are on the lifelike end of the scale, something that Nik advertise as a strength of their software. This is an entirely subjective decision, I like drama in a photograph, but like Techno or Heavy Metal, it can be wearing if it’s applied indiscriminately. Objectively, I decided that using realism as a yardstick would present a measurable and repeatable test of the software.
Those familiar with Nik Software will know that the user is presented with a range of presets, choose one that is close to what you want to achieve and fine tune it. All of the presets are achievable from the default image in any case, and some people prefer to start with the default and add to it selectively.
I use Adobe Lightroom to organise my pictures, here the original images are exported to HDR Pro. Note that the behaviour of other Nik plug ins is different, the user chooses “Edit in….”. This is slightly confusing, but makes sense since this is not an edit, but a composite of multiple images. The images are automatically aligned, but that doesn’t mean that you can throw random images at it. Ideally, the shots should be taken using a tripod so they match pretty exactly. I separated the images by one half stop, so in this case from -1.5 to +1 on the meter, giving me six images ranging from darkest to lightest. They don’t have to be in order, I shot the dark darler images progressively from 0 and then shot the lighter images. The software loads the images, aligns them and produces (in time) the default HDR image.
HDR Pro 2 does not work with presets from HDR Pro which may disappoint some people. The reason is the software has been radically overhauled, using new tone mapping algorithms and bringing the user interface into line with Nik’s other programs so legacy presets are now deprecated. It won’t take long before new presets are available, but for now, including the default rendering, there are 28 presets ranging from the realistic, through black & white to the properly hallucinatory. The screen can be split showing both the default and the edit in progress and the controls offer Nik’s proprietory U-Point technology to work on sections of the picture and a range of generalised controls allowing the user to adjust tone mapping, colour, contrast etc across the whole image.
I’m beginning to like this software, it achieves what should be the aim of all software; it allows the user to get on with the creative work rather than wrestle with obscure and obdurate user interfaces. I’m not a massive fan of the overblown school of HDR Photography although the results are undeniably impressive, however HDR is an interesting branch of photography. The software, be it Photomatix, HDR Pro or Photoshop itself is getting more sophisticated and it certainly has a place in the kitbag.