[Closed] HDR Photography

igm - very true, on all counts I think. Ultimately how an image looks is wholey dependant on teh person creating it and their tools. Whether it looks nice depends on who is viewing it and bears little relation to how it is created.

The whole question is actually whether photos should represent what is actually there and whether HDR increases or decreases the connection of the photo to "reality"

Absolutely. In my landscape photos I'm trying not to capture "reality", whatever that is, but to capture and give the viewer the feeling of what it was like to be there at the time. If that needs HDR, exposure blending, ND grads, B&W, whatever I'll do it.

Cameras don't see like people do. You don't look at a view and take it in all at once, your eyes flit across it adjusting exposure as they go and then you brain puts the whole thing together. That's why quite often a nice "view" makes a horrible photo. Your brain has filtered out the pleasing bits- cameras don't do that- that's where the photographer comes in.

coffeeking, I figured you'd just missed the 'grad' bit. 🙂

I don't have a problem with HDR. It's the same as any other manipulation technique - sometimes people get over eager with the sliders, whack everything to max and it looks cak. But, it can be a useful tool from what i have seen.
I am yet to try HDR, but fancy giving it a bash soon.

Over HDR'd images are no different from the images you see that have been opened in PS and had the saturation slider turned up, a heavy S curve put into 'curves' and then over-sharpened.

Heres a lovely HDR image (stolen from a photography board), showing the bits your eyes would pick out without over-doing it. This simply wouldn't be [i]possible[/i] without HDR. However maybe a sillywet ( 🙂 can never spell it right) would have been nicer in some peoples eyes - only the viewer can tell!

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Dooge,

The fuzziness in your shot is due to the branches moving and the program trying to overlay the branches that have moved while trying to align the rest of the shot. The same happens with ripples in moving water.

One way to get past this is to shoot RAW files, take them into your photo editing software and reduce the exposure two stops and overexpose by two stops. Take your three images (all exactly the same as they came from the same shot bar the exposure) and drop them into your HDR software, et voila. Just try to avoid halo's at the junction of your light and dark areas.

HDR is a useful tool for retaining shadow detail while not blowing out your highlights. It tries to replicate what the eye does naturally. I like subtlety myself, but can appreciate (some of) the more artistic uses.

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One of mine, ND Grad, long exposure to soften the water, photomatix to process the image.

@ coffeeking "This simply wouldn't be possible without HDR"

I remember combining two exposures of a landscape, one for the clouds, one for the ground, from scanned film negatives in Photoshop years ago. Isn't that much the same thing?

I never got very far with film photography but I think it was possible to use similar techniques with film in camera by shielding part of the image and thus effectively having variable exposure acros the image. Assume doing this at printing (dodge and burn?) isn't quite the same thing.

elliot - what you did with the two landscape exposures is effectively exposure blending, done "manually" rather than with a pre-designed software tool. Its very similar to HDR (HDR is actually more correctly a term for the file/storage format than the technique but the two get merged and the difference is debated a lot) but not the same. Sure you could manually take two or 3 shots of the shipwreck above and manually cut and slice all the parts together, but you'd just be doing the exact same thing as the HDR package would do. My point, after all that, is that HDR is simply a tool to allow greater creativity and possibilities using a limited medium. Without combining the two images and effectively doing HDR/exposure blending (as you did) you couldn't get that image. Again with the film photography, manually covering bright sections to bring down the exposure in those sections IS creating an HDR image, just using film and in a clever way. HDR is just representing a larger dynamic range in a single image.

Just a brief note, from my take on the subject:

HDR - an image with a higher dynamic range than "normal".
Exposure blending/tone mapping - modifying the info held in an HDR image so that it can be displayed on a low DR device while retaining a good set of the details from the HDR image.

We create and HDR by combining 2+ exposures. We then make it look good (hopefully) on screen by selectively blending/mapping the tones to 8-bit per colour channel depending on where the highlights/lowlights are blown out or underexposed.

All "HDR photo"s on computers have to have been exposure blended/tone mapped to show you the result on the screen. If you had a super-duper computer screen that had 10000:1 contrast ratio you could display HDR images without blending/mapping.

interesting... cheers for the info. Thinking aloud, but presumably a way of viewing a true HDR image on a screen would be to make an animation which tweened between a series of normalised images taken with different exposures. Might muck about with this...

Interesting thought. More out-loud thinking...

To flick between you'd need to cover all exposures in < 1/25th of a second, possibly <1/50th for flicker reasons. How fast is the response time of the phosphors of the CRT or pixel sites on the LCD, is it capable of switching at 3x25fps in order to equally display 3 (for example) images as one frame for the eye to see.
Are you limited ultimately to the min and max brightness of the screen - you'll never get the intensity of the sun from your monitor, or the blackness of floating alone 20 miles out at sea at midnight.
Wouldnt work with standard hardware, as your standard graphics card output simply outputs a voltage or digital level corresponding to 0-255, so the second frame would have to be 0.5-255.5 which physically couldnot occur. Maybe the gamma correction would be the way to do this, but I dont know if gamma correction simply clips the tones at the extremes when shifted - it must on a digital device?

I like your thinking though.

Oh sure each image would have to be within normal range, I was thinking more that you'd animate over a second or two - the same sort of time that it would take your eye to adjust. A bit more Googling seems to show this is exactly what's done in video games - you look down a dark corridor and can see detail, you turn your view to an outdoor window and you can only see a white rectangle, after a second or two the brightness reduces and outdoor detail is visible.

presumably a way of viewing a true HDR image on a screen would be to make an animation which tweened between a series of normalised images taken with different exposures

No, you need to invent some form of display with a larger range (a High Dynamic Range display if you will).

They are coming...

http://www.cs.ubc.ca/~heidrich/Projects/HDRDisplay/

http://www.bit-tech.net/hardware/2005/10/04/brightside_hdr_edr/3

The unreality of HDR photos (and CG imagery) when tone mapped for display on a standard screen (or worse, for print) is entirely due to how well the tone mapping is done IMHO, and of course we have 100 years or more of our culture looking at traditional photography / cinematography (and until recently computer generated stuff also aimed for 'photorealism' rather than 'realism'). But we have a much longer culture of looking at paintings, and if you look at some of the HDR images posted above and forget photography and instead think painting they make sense. Done well, they capture what you would perceive, rather than the necessarily extremely limited view that photography gives us (some of the artistry of good photography comes from working within those limitations of course).

Yep - the Pre-Raphaelites were doing HDR 100 years ago !!!
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Yep - the Pre-Raphaelites were doing HDR 100 years ago !!!

DrJ - on the other hand Vermeer appears to have anticipated photography 200 years early (and computer graphics techniques like ray tracing, radiosity, ambient occlusion) 300 years early... presumably because he restricted himself to painting what he saw inside his camera obscura rather than what he saw if he stepped outside.

@porterclough: I meant you'd display the full range of the image over time by varying the tone-mapping. But I guess this is just the same as varying the exposure per frame while using a video camera that uses some kind of exposure compensation.

Cool 🙂 Have you read [url= http://www.amazon.co.uk/gp/product/0330441604/ref=s9_simb_gw_xi_s0_p14_t1?pf_rd_m=A3P5ROKL5A1OLE&pf_rd_s=center-2&pf_rd_r=0DQA1NNP077QXQ0S8627&pf_rd_t=101&pf_rd_p=467128533&pf_rd_i=468294 ]The Apothecary's House[/url]? Not to give the game away too much, I will just say it touches on similar themes 🙂

@porterclough: I meant you'd display the full range of the image over time by varying the tone-mapping. But I guess this is just the same as varying the exposure per frame while using a video camera that uses some kind of exposure compensation.