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HDR Video a Reality
akaru writes "Using common DSLR cameras, some creative individuals have created an example of true HDR video. Instead of pseudo-HDR, they actually used multiple cameras and a beam splitter to record simultaneous video streams, and composited them together in post. Looks very intriguing."
Wiki explains it well:
is a set of techniques that allow a greater dynamic range of luminances between the lightest and darkest areas of an image than standard digital imaging techniques or photographic methods.
And their picture is a great example. If you expose the building well, the clouds are washed out. If you expose the clouds well, the building is dark. If you take pictures of both equally exposed then merge the photos, you now have a properly exposed building along with a properly exposed sky giving thus giving you more dynamic range. Think of it like instead of going to the lunch buffet and cramming everything into one plate, you go up to the buffet three times with three plates: one for salad, one for main course and one for dessert. With a little processing (trips) you end up with more range (food variety).
TL;DR: in Soviet Montage, camera manages multiple exposure for you.
Socialism: a lie told by totalitarians and believed by fools.
and it also has to give BJs
Snowden and Manning are heroes.
The bright spots are indeed an artifact of the HDR process -- partulcarly the tone-mapping algorithms. On its own, HDR is basically a method of capturing intensity values that would otherwise fall above or beneath the threshold of a camera's sensitivity. The problem is, when yo do that you end up with image data that can't be completely represented within the gamut of a printer or a screen. You could simply display a "slice" out of the data, which results in a regular images at whatever exposure setting you've chose, or try to "compress" the tone values into your available gamut, which results in a washed-out appearance. This is where tone-mapping comes in. What tone-mapping does is try to compute the correct exposure levels on a per-pixel basis, by comparing its intensity relative to nearby pixels. Ideally, this results in shadows being brightened to the point where you can see detail in them, and blown-out highlights brought toned down (analogous to "dodging" and "burning" in terms of old-school darkroom film processing -- the dynamic range of film is much higher than that of photo paper).
In practice, though, you end up with weird highlights around dark areas, like the ones you saw around the man's arms, because the tone-mapping algorithm is trying to maximize the local contrast in the image. It's brightened up the coat, and so it also brightens nearby pixels to compensate for the reduction in contrast. Some people try to adjust the algorithms to minimize this effect, while others try to maximize it for dramatic effect, or even an oversaturated, impressionistic look -- it's largely an artistic choice, though when done badly it can also be a sign of amateurism. Still others will manually composite multiple exposures to get the benefits of HDR imaging while avoiding its side effects entirely,
The Wikipedia article on tone-mapping goes into great detail on the different approaches to HDR photography, if you're interested.
You can get HDR to look 'fine' or whatever adjective you want to use. It's just hard. The tone-mapping software/settings that many people use will just go and create doll skin and haloes everywhere. But if you do everything well (hard work!) you can get some really cool looking stuff. For example...
http://www.flickr.com/photos/swakt1/2322363690/
http://www.flickr.com/photos/swakt1/2322366898/in/photostream/
http://www.flickr.com/photos/ten851/4972637653/in/pool-hdr
Somewhat like many other art techniques, when best used, you barely notice it at all. And that is the most important thing to remember. HDR + tone mapping isn't just a technology, it is an art. Being able to capture video in 3 different stops at once is great, but it'll still look like crap unless you treat it with respect and give it the effort and time needed.
Remember, HDR + tone mapping is just trying to create a low dynamic range image on a low dynamic range display that LOOKS something like what your mind perceives in a high dynamic range environment. Obviously, that's kinda hard, especially since the human eye can change its sensitivity as it focuses on different parts of a scene in real life, but not really when looking at a computer screen or print.
and it also has to give BJs
Just get a cheap camera phone, those cameras all suck.