Emmett Lollis+Basics of HDR Photography
About high dynamic range photography
Through my years as a photographer there were times when photography seemed bland and repetitive. With the advent of software assisted High Dynamic Range photography (HDR for short) a whole new world of opportunities opened up for photographers. With HDR you can increase the details that would normally be lost in shadow or over exposure, you can stylize a photo to bring it more punch, or you can turn an ordinary photograph into a piece of art.
Severe weather details captured in HDR.
What is HDR?
HDR is simply an image which allows the viewer to see an increased dynamic range which would not be seen in a normal exposure. An HDR image is typically comprised of 3 or more photos of the same scene taken at different exposures. The most common HDR photograph is made up a photo taken at a normal exposure, a second photo which is under-exposed, and a third photo which is over-exposed. The purpose of the under-exposed photo is to bring details to areas which would normally be blown out. The over-exposed photo serves to bring detail to the areas which would be lost in shadow.
What you need to create an HDR photo
To begin shooting in HDR you will need a camera with manual settings. The reason you need this is to capture the varying exposure levels. A fully automatic camera will adjust the exposure on it's own for each shot so it just won't do. The best option is to have a camera with Automatic Exposure Bracketing (AEB). AEB allows you to pre-set exposure increments for each series of photos. If the camera is fast enough, this allows you to hand-hold the camera while taking HDR photos. If you don't have AEB available, you can still take HDR photos by using a tripod and manually adjusting the exposure between shots. You will also need some form of software which you can use to combine the images. We'll get into that later.
What scenes work well with HDR?
Good subjects for HDR photography start with high contrast scenes. Sunrises and sunsets are the first that come to mind because they are nearly impossible to capture without severely over/under exposed areas. While this type of scene will surely benefit from a high dynamic range, I have found that overcast days make for some of the best HDR images. In my personal experience, I use HDR extensively for weather photography. The effects of HDR look incredible with severe weather and snow storms. I also like the look it gives to city scapes and country scenes.
Images that work well: Sunsets
Images that work well: Weather / Cloudy Days
Images that work well: Snowflakes in winter really add to the artistic effect.
What scenes don't work well with HDR?
The first bad subject that comes to mind when dealing with HDR is portraiture photography. HDR by nature enhances details which you wouldn't ordinarily see in a photo. The last thing your subject wants to see is a detailed view of their perceived imperfections. Macro's also tend to be bad HDR subjects. Since macro's are done on such a small scale, it takes only the slightest movement to distort the merged image beyond repair. Along the same lines any moving subject would be difficult to catch in three or more shots at the same position. Also, blowing tree branches or blowing tall weeds can cause unwanted artifacts in the final image for the same reasons. While these are general situations to avoid HDR, remember that rules are meant to be broken.
Exception: Some portraits look fine in HDR, in this example, actress/model Dina von Sinn on a stairway.
Taking the high dynamic range photo
For the purposes of this tutorial we will assume that your camera doesn't have AEB. If you don't have AEB then you must use a tripod in order to keep the images in close alignment. The normal rules of image composition apply, if your scene doesn't look good, HDR won't help much. Also, keep in mind that for HDR, in most cases you will want a pretty wide depth of field, in most cases a shallow depth of field won't do HDR justice, however there are exceptions to every rule. You will need to determine your base exposure first. Most cameras have pretty good built in metering but you can always use an external metering device. It's a good idea to meter somewhere in between your high/low exposure areas to determine a good mid point. In general the more exposures you have, the better the final HDR image will look, but 90% of the time, three exposures works very well. You will need to determine how far over/under exposed you want to go. A good starting point is a normal exposure, a +2 stop exposure and a -2 stop exposure. Since we are combining images it's best to vary the shutter speed to get each exposure (Depth of field changes may causes issues when you put everything together). When it's time to shoot your HDR sequence, you can start with the lowest exposure or the highest exposure first, it really doesn't matter. Remember to minimize any potential movement between shots to make our job easier in post production.
HDR brings out tones in the clouds that would otherwise be missed.
Creating the HDR image from our source photos
Now that we have our source images, it's time to combine them to create the HDR photograph. There are many software options available when it comes to creating our final image. The most popular HDR software out right now is Photomatix Pro. This is the software I used to create a majority of my HDR photos and the features allow you to create anything from photo-realistic HDR compositions to amazing artwork prints. Adobe Photoshop has had HDR functionality for several versions now but the older versions just weren't up to par with Photomatix Pro. With the release of Photoshop CS5 however, the game has changed. I have effectively switched from Photomatix to Photoshop CS5 to merge my HDR images. Another effective means to creating an HDR image is to load each exposure onto it's own layer in an image editing program and manually blend the under-exposed areas onto the highlights and over-exposed areas into the shadows. I am working on new tutorials which go into more detail on the best ways to use Photomatix and Photoshop CS5 to create high quality HDR compositions. I will link the new tutorials to this page as soon as they're ready!
Update
I've completed a full tutorial on creating HDR Pro images in Photoshop CS5. Check it out!
Article by Emmett Lollis Jr. November 4th 2010
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