When I was in school, I seem to recall one of my professors telling me that when it comes to photography “the more information, the better.” This was in reference to taking digital pictures in color and converting them to black and white vs. just taking them in black and white. The theory is that if you need to, you can always take detail away, but it is much harder to add detail. In theory, HDR (High Dynamic Range) photography is a great idea for capturing the most information possible, but I’m still on the fence about its real value.
But before I get to that, what is HDR photography?
HDR photography is a process. It is not a filter, a program, or an attribute of a specific camera body (although all of these things can be relevant to the process). It is an answer to a question that has been around about as long as photography: how do I get the most detail in all ranges of tone? An example of this problem is taking an interior shot that includes a window into a sunny exterior. You can properly expose the exterior parts while underexposing the interior. Or you can properly expose the interior while overexposing the exterior. Or you can shoot for the middle and end up with some blow outs in the white and solid blacks in the darks. All of these can work, depending on the situation. But wouldn’t it be nice if there was a way to get all of the detail across the entire range?
In analog photography, there were developments in the film itself that allowed for higher and higher tonal range. Since you could burn and dodge areas, you could get a lot of detail throughout the range. But there is no film in a digital camera. Another technique that does apply to digital cameras is taking a series of bracketed photos that ensure proper exposure across the whole range. Then you could print the darkest areas from the lightest exposure, the lightest areas from the darkest eeposure, and the mid tones from all of the pictures in between. Now this was less than ideal for film photography because burning and dodging are hard enough, but creating an even merger between three different photos. . .that is time consuming and difficult. But digitally, you can let the computer do it while you go get a sandwich. . . sort of.
Digital cameras tend to bunch up when it comes to extreme lights and darks. The result is color noise in extremely dark areas and a complete lack of any information in the extreme light areas. If you’ve ever under or over-exposed an image and tried to digitally correct it this becomes even more apparent. Without going into too much detail, this has to do with how pixels are used to record and display color and tone. So, by making the light areas less light, and the dark areas less dark you get more detail or depth in the overall image. All very cool stuff, but you can’t just throw the images together and expect good results. It takes time to merge the photos (some cameras can do this, or you can use Photoshop CS3+, or a specific tool such as Photomatix) and then it takes work to get all of the exposures to work together to make an overall pleasing image. Still easier than crop, burn, dodge, repeat. . .but more time consuming than taking good old fashioned LDR (Low Dynamic Range) photos and working with them a little in post.
But wait, there’s more!
Having an HDR image is kind of like having too much information. . .there’s going to be some that gets wasted. Most printers and monitors can only display images as LDR. So it may initially look worse as opposed to better. That’s where tone mapping come in. Tone mapping takes different forms for different applications but it comes down to taking your HDR image and specifically filtering it down to work with LDR devices. This can allow you to retain the detail you want and actually show it!
On top of allowing for a large amount of detail across a wide tonal range, the extra range also allows for a myriad of special effects. More hue data means you can really boost the colors, you can smooth and enhance tiny parts of the picture based on their surroundings to achieve surreal illustational effects or you can get a look that is almost hyper real just by manipulating the light and dark points and applying an unsharp filter. It is all great fun, and the results cover a wide range of styles (Flickr’s HDR Pool has great examples of the wide range of HDR photography). So why am I on the fence?
Here are my major misgivings about HDR photography:
- It can be very time consuming compared to taking better individual picture.
Admittedly, there is a cap on the quality of single pictures and some scenes just cannot be captured that way, but consider what you are taking a picture of and weigh the options
- I don’t know if there is an inherent value to the more illustrative techniques, or if it is a trend that will fade
The effects are really cool (and can even be applied to single photos with the help of some programs). But is that all that they are?
- HDR can be very expensive
Okay, so I know I said that it can be done with any camera and most image processing software. To do it well, however, you pretty much need a good tripod ($100 – $200) and a digital SLR (You can get an old Nikon D50 for around $200 used, which is a fine body). To do it efficiently, you need specialized software (most of the specific HDR applications are around $100 and up) and either a good computer or a lot of patience. Now I know that is not a complaint for most photographers (it isn’t a cheap hobby or profession) and that if you already have most of these things then its no issue.
So, I’m on the fence. I don’t know how much interest to invest in HDR. If you want to learn more about it, Stuck in Customs has a great tutorial and also some promotion codes to get a discount on the software they recommend. For all the arguments, I wouldn’t be surprised if my stock.xchange gallery started looking a little more dynamic.
Here are the images next to each other, for comparison: