Is HDR a "natural" view from human perspective?

[ken_l3]

<p>A high dynamic range scene is always a challenge with my micro four thirds camera, which has a narrower dynamic range than pro-level DSLR cameras. My choice in such situation comes down to (1) fill flash, (2) bracketing, and/or (3) HDR. I prefer fill flash when possible, but it's not always possible. I've recently started dabbling in HDR in post processing. But I've come to wonder whether a HDR created in PP is a "natural" photo. I understand the human eye has much perception in better high dynamic scene than the best digital camera, but a HDR photo seems to go beyond the human's own capability, and thus, looks unnatural. Yes, not all photos have to be "natural" from a human perspective. As a matter of fact, certain shots are designed to be "unnatural"; e.g., slow-shutter speed motion shots. But when it comes to dynamic range, a HDR photo looks too unnatural. Maybe it's because I haven't gotten accustomed to them yet.</p>

[wclark5179]

<h1>"Is HDR a "natural" view from human perspective?"</h1>

<p>It can be debated; either way, the image does provide a natural view and/or maybe it doesn't.</p>

<p>This can be discussed by others here and at other places!</p>

<p>My brain can process visuals from my eye that, unprocessed, would be viewed quite differently than the processed images.<br /> What is real? Could I make grey white, yellow red, blue green?</p>

<p>What about those insects, like some butterflies that "see" using the UV spectrum?<br /> HDR provides another view; many like it because it shows something different, enhanced; perhaps some will say it shows what the eyes see but the camera doesn't.<br /> What do you think?</p>

<p> </p>

[James G. Dainis]

Looking at the shrubs in my backyard, I can see the branches or trunks in the shadows beneath them. A trick I learned to see what the camera sees is to squint my eyes almost shut. When I do that the shadow area beneath and inside the shrubs turns black. I know that is what I would get with a photo. HDR can be used to capture that shadow detail. That would be more natural but most HDR work I see looks over saturated.

[Tim_Lookingbill]

<p>Check out the site below to get the many versions of HDR...</p>

<p>http://www.hdrlabs.com/gallery/realhdr/</p>

<p>Natural is the one I'ld say looks closest to human vision.</p>

[mike_hitchen]

<p>I think that it is hard to sayhow the eye 'sees' HDR scenes. As I undsertand it, the eye flicks around a scene, constantly adjusting the pupil to adjust for variations in brightness and the brain meanwhile builds a complete picture. Sometimes it sounds to me like the brain does a bit of pano stitching :) So whether the eye/brain 'sees' in one go a single complete HDR image as presented in a photo I am not sure.</p>

<p>I think many HDR 'look unnatural' because of the way they have been processed rather than being a fundamental property of HDR - I have seen a few that I would not have known were HDR had I not been told. I think all you can say is that an HDR image shows the range of tones that were in the schene.</p>

[JamesFarabaugh]

<p>From what I have read different HDR programs will generate different images, depending on their tone-mapping algorithms. Some programs produce more "natural" images while others produce "stylized" images.</p>

[AlanKlein]

<p>Trust your own eyes.</p>

[richardsnow]

<p>If done tastefully, HDR can look very natural. I've also started dabbling in HDR and made a very nice one this weekend. </p><div></div>

[ken_l3]

<p>@ Richard Snow<br>

Wow, nice work! That photo is as natural as any that I've seen. I wouldn't have known it was an HDR if you hadn't disclosed it.</p>

[paddler4]

<p>Ken,</p>

<p>I had the same question when I first approached this problem. A lot of HDR work looks very unnatural. An alternative to HDR is exposure blending, which in my limited experience usually provides a much more natural appearance. Google it, and you will find a bunch of references. I use Lightroom Enfuse, which is a plugin. It's very easy to use, and I have been pleased with the results.</p>

<p>With apologies to those who have seen these before, I'll post a comparison between LR Enfuse and HDR Pro (in CS5), from the same images. I'll put the HDR first. The color difference in the sky needs no explanation. The rocks are accurate in the Enfuse version, not the HDR. True, with enough work, I could probably have gotten the HDR to look more like it had been taken on planet earth, but exposure blending makes it much easier. The manual "HDR" that some people do with layers in photoshop is actually exposure blending.</p>

<p>Dan</p>

<p>HDR:<br>

<img src="http://dkoretz.smugmug.com/Other/test-shots/50442HDR2/960908746_c5zpr-L.jpg" alt="" width="758" height="600" /></p>

<p>Exposure blending:</p>

<p><img src="http://dkoretz.smugmug.com/Nature/Outdoors/MG5044-blended/962954318_yKUb7-L.jpg" alt="" width="800" height="575" /></p>

[craig_shearman1]

<p>HDR is just one more tool in the toolbox, no different than putting filters over the lens, using fill flash, dodging and burning or using variable contrast paper in the darkroom, or using layers in Photoshop. Sometimes these tools are used to make the image look as much as possible like it did to the eye. But very often they are used to make the scene more dramatic or interesting -- think about clouds popping against a deep blue sky because of a polarizing filter (or red filter in B&W). Or an Annie Leibovitz picture shot with heavy fill flash against a sunset background. Like anything else it can be overdone, but that's a matter of skill and taste, not an inherent flaw.</p>

[Tim_Lookingbill]

<p>Don't know if anyone's aware of this or not, but the way most HDR's turn out, you run the risk of producing dark looking prints from a scene that the eye and brain knows is much brighter. I see it in the posted HDR images here and in the images in the HDR site I linked to.</p>

<p>It looks great on a bright LCD even though they appear as if you're viewing them with polarized dark sunglasses, but a print is going to be a totally different (and maybe disappointing) experience especially when viewing them in normal ambient light like in someone's home.</p>

<p>I'ld suggest you study Dutch master painter's work (Vermeer/Rembrandt, etc.) to get an idea on how to tone map the dynamic range of a scene to make it appear as the eyes see it. They REALLY studied up on this and perfected it.</p>

<p> </p>

[richardsnow]

<p>Tim -</p>

<p>I printed the image on the previous page as an 8x10 and a 16x20. Both look (nearly) identical to the image I see on my screen...</p>

<p>Color correct your monitor and view my image in Firefox or Safari and it shouldn't look too dark.</p>

<p>RS</p>

[seth_.]

<p>Sometimes natural light produces great vistas which hit you directly in the eye. Sometimes I've witnessed scenes that could be similar to an HDR image, but generally, no.<br>

Well, it can also depend on whether you're on uppers or downers.</p>

[dbcooper]

<p>The whole idea behind high dynamic range imaging (HDRI) was to get an image that looks closer to what the eye can see as opposed to the limitations of the dynamic range of a camera/photograph. Different software processes this in different ways, and some folks overcook the processing and end up with various stages of a surreal look, and that got popular to the point where some folks think that's what HDRI is all about.</p>

<p>If you have decent HDRI software, good post-processing skills, and start with the right kind of image with the right bracketed exposures, then IMO, you <em>can</em> get images that look very much like what the eye would actually see, and that look very natural.</p>

[lachaine]

<p>The whole idea of HDR and related digital gimmicks like active d-lighting and others that purport to render a scene to look more like the human eye sees it is fundamentally flawed, in my opinion.</p>

<p>I think this because a photograph (or image if you prefer) is not the scene. It's a photograph of the scene. No matter how much research they did into how humans see things, looking at a real scene and looking at a photograph of it is not the same thing, and trying to make it so ends up looking artificial. A more limited "dynamic range" is what makes a photograph work as a photograph, and it's essentially the reason why slides looked so impressive compared to colour negative film.</p>

[richardsnow]

<p>@ Pierre Lachaine</p>

<p>HDR, IMHO, is now helping me make images that I normally wouldn't be able to take with a digital camera. The image I posted was taken at sunset and, when exposed for the lighthouse, the rocks appeared too dark to see. Conversely, when exposed for the rocks, the lighthouse was blown out. By averaging the exposure, I got some details from the rocks and moderately overexposed the lighthouse, but it just wasn't what I was trying to achieve.</p>

<p>The ONLY way I could get the image I wanted, (which was what I posted), was to render an HDR image.</p>

<p>The biggest problem with digital, (when compared to film), is it's limited dynamic range. Film has a much wider dynamic range and the ability to push exposures and retain detail without blowing out highlights.</p>

<p>I'm of the mind that you try to get it right in camera, but when needed I have an extensive toolbox of post processing techniques to create the image I intended if I can't get it perfect in camera. HDR imaging is just another tool in my photography toolbox. I will use it when the image I am trying to capture requires it, but generally won't use it in my day to day photography.</p>

<p>RS</p>

[markci]

<p>An HDR image may or may not go beyond the human eye's ability to capture the range of the scene (most probably do not). But in either case, that's not why they often look unnatural. They look unnatural because they COMPRESS the range of the scene into the range of the reproduction medium, which is far less. You are reacting to the fact that the shadows and highlights are far closer together tonally than they would be in the original scene. Conventional photography does this as well, but to a much lesser extent.</p>

[tom_mann1]

<p><em>"...You are reacting to the fact that the shadows and highlights are far closer together tonally than they would be in the original scene...."</em></p>

<p>In many HDR tone mappings, something far worse often happens: tonal inversions. Locally, the normal succession of dark to light is preserved, but over larger distances in the image, this often doesn't hold. For example, the very slightly darker bottoms of clouds might wind up in the tone mapped version as darker than some of the shadows on the ground, even though this was absolutely not true in the original scene. This is what happens when you crank up "local contrast".</p>

<p>As Mark Ci pointed out, global contrast reduction is commonplace in conventional photography, particularly, film based imaging, however you never see local contrast enhancements in film unless the photographer *really* likes to work in the darkroom.</p>

<p>Tom M</p>

[Tim_Lookingbill]

<p>Richard, sorry for not being more clear.</p>

<p>I was referring to Dan's image of the mid day lit landscape. Frankly I prefer his Exposure Blending version. The HDR version looks too dark (though richer looking like a slide) pretty much as if I'm viewing it with dark polarized sunglasses. I notice this tonal characteristic in quite a few Ansel Adams B&W landscapes. Prints I've seen of his work look very dark for such brightly lit scenes.</p>

<p>Your image is close to dusk and looks as it should for that type of lighting. Good job at bringing out the rock detail in the shadows BTW. </p>

[david_henderson]

<p>Is it possible to use HDR to without looking unnatural ? Yes, even though it pulls shadow and highlight tones closer together, and indeed it's difficult to see what use it would be if it didn't. </p>

<p>Is it possible to use HDR to make images that look highly stylised and nothing like natural? Sure. And some people like them like that, but nobody's forcing you to like or dislike them. </p>

<p>The sad bit comes when the photographer attempts to achieve the first but manages only ther second, maybe without even realising it. Also where a large majority of photographs of particular subjects -for example interiors of abandoned buildings-seem to have the same stylised look rather than the photographers using their imagination and skill to create a more distinctive appearance. Its fashion in the way that certain hairstyles were in the 60's, and in the same way that many landscapes were force-fitted into a panoramic format a decade or so ago. People still make panoramics, but on a more discriminating basis, and I'm sure something similar will happen with HDR.</p>

[richardsperry]

"But when it comes to dynamic range, a HDR photo looks too unnatural"

 

That is most likely because in a high dynamic scene, the actual scene, you "sense" the pupillary reflex.

When looking at an image, in a well done HDR image, you are looking at a single lighted object.

You perceive that you should "sense" the dilation or constriction of the pupil, and you don't.

So it seems unnatural.

 

 

Well, that's my guess anyway.