HDR Sucks.
OK: most HDR is poorly done, and that’s what sucks; even with CS3, there is no free lunch.
“HDR! Better than sliced bread! Faster than a speeding bullet!…”
As I write this, it’s the winter of 2008, and you cannot pick up a photo magazine, computer magazine, or visit a website without someone screaming at you about HDR photos.
“High Dynamic Range” or, as I call it Too Much of a Good Thing.
Remember this? Back when the Macintosh first came out, and WYSIWYG and Postscript came along, it was at long last possible to create straight lines, and use various types without having to be a graphic artist.
Proof that PostScript did not a graphic designer make, was amply supplied by thousands of barely readable newsletters sporting 46 different fonts on each page.
It was horrible. Look – just because you bought a hammer, doesn’t mean you’re a carpenter, but it does make every problem look as though it can be solved with a nail.
http://www.toxel.com/inspiration/2008/11/15/beautiful-examples-of-hdr-photography/
http://thedesigninspiration.com/articles/40-beautiful-hdr-pictures-you-would-be-amazed/
Well, here we go again.
Photographers have historically been plagued with low dynamic range (the amount of detail from the blacks to the whites, usually expressed in EVs or f-stops.)
Early tintypes and early film had a limited range 5-7 stops. Film runs from 8 to 19 or so stops. A digital camera runs from about 9 to 12 stops.
The human eye is about 7 stops. That is, when you’re looking at something in particular, your iris settles on a size, exactly like the aperture of a camera, and at that given size, you have the ability to see a light intensity of about 150: 1 (or just slightly greater than 2^7 – [7 stops].)
Since early photography was also about 7 stops, it was well received… but ultimately a little frustrating. Looking at the photo as a whole, the image was perfectly satisfactory, but because a photograph is a fixed moment, we always take the implicit invitation, and look into it, trying to pick out interesting details. And with a limited EV range, the detail was lost, either in the shadows or the highlights.
Thus photography became at least in part, a quest for additional range. But that quest can be carried only so far, before it starts going “over the edge,” and then no longer looks “right.”
It’s that threshold we seem determined, like a child with a new toy (or a wanna-be graphic designer with Postscript fonts) to exceed.
Look up from reading this right now. Glance around. Look at bright areas and dark areas. Really look – how much can you _actually_ see in the darkest shadows? What happens when you look at something bright? Can you see it, while at the same time, see into the shadows?
No, of course not. The iris opens and closes. In fact, you cannot -clearly- see anything except the tinniest field just around your direct line of sight, and focus. (Your mind may fill in assumed details, but as I said: really look, paying attention to what you can, and cannot, see.)
My point is that what you see is 7 EV… and if you stare into the shadows, you’ll open them up a bit… but not more than 7 EV. Ditto for bright areas. And at no time will you ever see more than 7 EV. It’s a sliding, but fixed, range. We don’t see much detail in dark areas (our eyes “have to adjust”) and humans are very bad at seeing in the dark. We do much better with more light… but it can get to be too bright for us as well, although it’s not as several an impediment as the low light level issue is.
So I’d suggest that about 12 will give us enough leeway to look into the shadows, and recoup some of the blown out whites. (The famous Zone system had 11 tonal areas.)
Fortunately, I own a camera that will provide me with about 12 EV, but what many do, and what I’m discussing here, is the 3-shot, 2 stops over; 2 stops under; one right on; blend-them-together technique so avidly discussed these days.
But, and here’s the problem: it’s not “evenly spaced.” That is, when you overexpose by 2 stops, you’re making the shadows 2 EV brighter. And in the 2 stop underexposure, you’re cutting down the highlights by 2 stops.
In short, you’ve giving the viewer a 4x extension of the light in the darkest areas where we do not see well, which is completely abnormal, since humans don’t see into shadows well, and then, with the underexposure, you’ve _cut_ (not extended) the range on the high end.
In short, you have a picture with a 9 EV range, pushed toward the shadows.
I’ve seen on the cover and in feature articles of well respected journals, read by many a professional, photos with such “high dynamic range” and they look terrible!
The problem is what happens to the middle range: the main perceptual area of the photo as a whole: it becomes “thin.”
In fact, I actually mistook the cover of a recent “Photo Techniques” for a pencil and watercolor drawing on first glance… as did my wife, who is a painter. It was a photo taken inside an old, trashed and abandoned room, with windows opening to a sunny day outside.
Yes: I could see into all the shadow areas, and make out details out in the bright sunlight. However (and here’s the point) I have never had such an experience in my real life, using my real eyes… nor has my wife, which is why, on first look, we took the photo to instead be an illustration: it simply had no relationship with reality.
In fact, it reminded me of what happens in poorly done audio these days: it’s compressed (I’m talking frequencies, not file size here) beyond all belief so that it can be played loud. Musical nuance is gone; harmonics are gone. It’s a large, flat monotone without any human expression…
… and it fails as music.
Most HDR is similarly overdone: “brightness” is just tacked on to the image in a haphazard way, “opening up the shadows.”
It fails as a photo, as it’s no longer within the range of human experience.
Fortunately, just as we are no longer stuck with 46 fonts per page, and the wanna-be graphic designers eventually returned to their day jobs, leaving the trained designers to produce nice works with no more than 2 fonts per page, there _is_ good HDR.
It’s not simple to do correctly, but at least there is a correct way to do it.
First, make sure that you’re not shooting automatic anything! Particularly, be sure automatic white balance is off. Turn off auto-focus. Use a tripod. Shoot -2, 0 and +2 EV.
The, for your print, you open up the shadows, but not necessarily all two full stops. You put the extended range in the _middle_ of the picture, not at either end. Leave a bit of blow out if it’s called for. Leave some pure black.
You want darkest pure blacks; blacks with only a hint of shape; blacks with some tone; blacks with some texture. If you open it up so much that none of your blacks fall in the first three categories of that list, you’ve overdone it.
Extend the detail in areas of the photo, not all over it. THINK about what you are doing. If you are sharpening to draw the eye, then provide the extra range there, where the eye is drawn. That’s what masks are for!
Open the shadows a bit, but only in the deepest areas; do not let it spill over into the middle tones. Opening the shadows should be done very modestly if there is a 150:1 tone range (ie daylight) but can be done more strongly when the tone range is 20:1 (a darker subject) because that is the way our eyes work.
Do not increase the shadow detail in the middle range (or at least not much) – keep it at 8 or 9 EV… for exactly the same reason. (Ansel Adams considered the bulk of the image to be within the center 9 zones.)
In fact, go look at some good black and white photos, and notice the tone range. After all, EV is a measure of luminosity, not color. Study the prints of Weston, Adams and the other great B&W photographers. There you will find a rich, velvet and lucious range of tones, all of which invite investigation.
Personally, the first thing I do when working raw is turn off the color and look only at the luminosity, in LAB, and get that set right. Then I pop the color back in.
Having HDR can be a good thing, yeilding spectacular and moving prints… or it can be like a newsletter with 46 fonts per page.
If photography were a entirely mechanical craft, then Photoshop could do all the work for us, but it’s not: it’s an art, which takes human experience, skill and judgement to do correctly.
You want a great photo? Plan on spending some quality time with it.