I became curious about High Dynamic Range photography a few years ago and finally got it out of my system. Yeah, it was a mini obsession for a summer of shooting. Let me tell you what I know about it, what I found useful, and how and when to consider using HDR.
There are many articles describing the techniques about how to do HDR, and in fact, many cameras come with an HDR set embedded. That is how popular HDR became, there are still loyal followers of HDR but for me, it rose my curiosity and I took the time to quench my desire.
What is HDR and what problem does it solve? Your wonderful camera/sensor is limited across the lightest to the darkest shadows and somewhere in between those two extremes is good exposure. While your human eye can resolve the range of light between light and dark your camera can not with a single photo (or at least not yet), your picture will turn out either: highlights are blown out or shadow too dark. What HDR allows or facilitates is capturing extreme highlights, down to the deep shadows using many individual exposures, that is, you take one photo to capture the highlights, then another with less exposure, then another, until your last photo capturing the deep shadow details. You may wind up with 12 images in your HDR grouping. Once you are back in the studio, you then process these images using a tool such as photoshop - merge these images to generate one image with a tonal range that shows all the details high, mid, and low. Many tools are on the market for this purpose (freeware and payware), and take the tedious details of trying to merge and align the images manually. When done correctly and with some restraint, the results can be pleasing.
I briefly gave away the secret of HDR above - It is a simple process, and even modest cameras can do it, here is what you need:
1. A tripod - or at least I recommend a tripod for best results, why? as you decrease the shutter speed to capture the dark shadows you may find you are shooting down to 1/2 second, thus hand-holding is not the best option. If you have a wireless release that would be nice. Reduces camera shake as you do each exposure.
2. A camera with manual settings: Shutter and Focus that you can control. I think manual cameras are probably best suited for the job anyway.
3. How To: Once your camera is set up with the "correct first exposure", in focus, with aperture Set manually, take the shot, then examine your image - it should be pleasant, like all the other photos you normally take. Now comes the fun part: Without touching the focus or aperture and not moving the camera (too much), take 4 exposures up, then reset to the Original "Correct first Exposure" setting then, take 4 exposures to down.
HDR Shadows
HDR help reduce the dark shadows of the harsh sun.
On paper here is an example how it would look like: f/7 125 (first picture), then f/7 160, 200, 250, 320 (back to f/7 125), then f/7 100, 80, 60, 50 - your mileage may vary depending on your camera and first exposure starting point, but you get the idea.
Another way is to use your cameras exposure compensation dial - the problem is, some cameras only allow 3 stops up or down while others may accommodate as many as 9 stops either way. Besides, some cameras allow you to set how far apart the compensation is such as 1/3 stop or 1/2 or even a full. I would stick with the 1/3 if you looking for a more natural photo.
To Note: The more exposures you make and the closer those exposures are together the smoother the tonal range will be in the final photo, and also - give you options as you process the group. I don't always use all the exposures I make in a grouping.
What Subjects are best suited for HDR: Most subjects that are static. Since you taking many photos of the same thing - the movement of your subject can be a problem between shots such as nature shots with trees (blowing in the wind). Some images can turn a plain photo into a surreal image, Once you begin to do HDR you soon discover how best to use it and when, or at least I did.
Additional Tid Bits: There is a company that offers a dedicated device that interfaces with some cameras to totally automate the process as well as bring you some new features such as time-lapse if you wish to dive into that - Promote Control (link below).
In conclusion: HDR is a fun way to extend your photography and when done correctly can make your images stand out. I recommend you give it a whirl, does not cost anything to try!