Tutorial: Shooting a High Dynamic Range Photo (HDR)

« Tutorial: High Dynamic Range Image (HDR) Movement

First you will need a camera to capture your scene in a HDR photo. I use a Nikon D200, but you can use anything. Even film, if you like. I have done HDR photography with film. It takes more time than it does with digital, not only because of the development time, but also because you will need to scan your dias (or negative) and afterwards you will need to align them.

Only thing your camera really needs, is some way of letting you set the shutter speed. Besides your camera you will probably need a tripod. I have a very old tripod, a Franka. Don't think they make them anymore. You can do HDR photography without a tripod and i have managed to successfully capture nine exposures by placing my camera on my legs. Often its more a miss than a hit.

If your camera permits it, shoot RAW. If you have to shoot jpg, then turn of any in house camera image adjustment. Like contrast boost, color enhancement and so on. If you do shoot something else than RAW, remember to set your white balance.

Select an aperture that you think is appropriate. For daytime shooting choose something that will let you capture the scene as you see it. Just as if you shoot a single picture.

For lowlight and nighttime photography, you will need to keep the shutter speed down. I try not to go above 30 seconds, mainly because its easier to bracket them, but longer shutter times also tends to let more noise into the data captured by your digital sensor. I shot the Silo picture above, at Islands Brygge with 3 manual shots; 20 seconds, 1 minute, 1 minute and 30 seconds at f/11.

Going back to the construction site photo. Switch your camera to spot metering (its called that on Nikon's cameras, could be something else on yours). Point your lens at the darkest area and turn you shutter dial until your meter reads '0'. This means that your image is correctly exposed for that part of the image. For the construction site photo above my reading was 8 seconds. Now, point your lens at that the brightest area. I chose the lamps on one of the cranes. Adjusted my shutter speed until the reading was '0' again. This time it gave me a shutter speed of 1/30.

If all this is very confusing, try looking at the image below "Electronic Analog Exposure Display". Some of the information is specific for Nikon D200 but you should be able to get a general idea. Thanks to Nikon for letting me publish it here.

So now we have two shutter values, 8 seconds and 1/30 second. To get details in the darkest part at f/5.6, we need an exposure of 8 seconds. To make sure we do not get any burned highlight we need a 1/30 second exposure at f/5.6.

I prefer to take my shots at an +/- 1EV spacing, but you can do what you like. I think that +/- 1EV gives it a more smooth look. If you have a camera that only lets you bracket with a +/-2EV then just use that. Later on you can experiment with +/- 1EV in manual mode.

Take your first picture at 1/30. Turn your shutter until it reads 1/15 and shoot again. Turn your shutter until it reads 1/8 and shoot. 1/4 and shoot. 1/2 and shoot. 1 second. 2 seconds. 4 seconds. 8 seconds. Nine shots later and you have what you need.

What we have shot manual is -4, -3, -2, -1, 0, 1, 2, 3, 4. Its the same thing as setting your shutter time to 1/2 (thats the '0') and then letting your camera do nine brackets for you. 4 brackets down, 0, and then 4 brackets up.

What you might have figured out now, is that with each 1EV step, we are dividing (-1EV) our shutter speed in half or multiplying it by 2 (+1EV), doubling it.

EV is the shorthand for Exposure Value. You can read more about it here Exposure value - Wikipedia

For nighttime photography i usually measure the darkest part that i want detail in. Then i switch my camera to bracket mode. Turn my shutter speed 4EV up. In the above case that would be to 1/2. Then i use my Nikon MC-30 release cable to make sure i do not shake the camera while shooting and also i have my Nikon D200 in "Exposure Delayed Mode". Then i shoot the following sequence: 0,-4, -3, -2, -1, +1, +2, +3, +4.

Sometimes i start at 30 seconds and move 4EV up. That gives me a start shutter speed at 2 seconds and bracket nine shots. Then i carefully move 5EV up and then 4EV up, ending a 1/250. Then i bracket nine shots again. This will give me 18 shots.

If all 18 shots contains useful data, this will eventually give me a HDR that has a potential contrast ratio of 8.000.000:1! not likely, but ..

My nine brackets alone would (still potential) give me a contrast ratio of 16.000:1. Thats way, way more then our monitor can show and that is why the image about look really crappy.

So we can not see it. We can not print it, so we can not hang it on our wall. So up until this point it has just been a waste of memory cards and time... .. . or has it?
Well not really cause we're going to convert our nine shots into an HDRI and then process it with Photomatix into a LDR, so we can show it on screen, and even print it.