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Our eyes can look at a scene with bright lights and faint shadows, and see details in both of those extremes. However, our cameras cannot perform that feat. They're limited to capturing a superior view of a much narrower range of brightness differences than our eyes. But with some software magic, called HDR (High Dynamic Range) photography, we can defeat our camera's limitations and approach the view our eyes perceive. The trick is to capture several images with different exposures and combine them using software to emphasize the shadowy parts while de-emphasizing the bright parts. I'll use an image of an interior of a church to illustrate the process. The photo below shows a view of the Jefferson Avenue Presbyterian Church, as your eyes might see it and you'd wish your camera could capture it. It's actually made from 5 different exposure photos that I'll show below, with a modern high-end semi-professional camera which I use. (Click on this or any other photo on the page to expand it, click again to put it back into the page).  The best single photo my camera could take of this church (without using HDR) is the one shown below.  It's obvious that the church's lamps are overexposed, showing no detail at all, and the ceiling and nearby balcony pews and area above the organ pipes are too dark to show any details. Compare this best-single-photo to the top photo above and you'll see many more defects, such as the lack of detail in the stained-glass windows and the bottom of the ceiling support arches and even the hymn-number plaque at the lower-right corner. To create the higher-quality image, you must take 3 or more different exposures and combine them using software. It's best to have your camera on a tripod and use a remote shutter release if you can, especially if you're taking photos in the darkness of the interior of a church or a scene at night, but if you cannot, just handhold your camera and keep it as still as you can so all the exposures are aligned as closely together as possible. The software usually has an option to "align images", which usually works quite well. If you're a beginner...... then leave your camera in Automatic Mode (A) and find the Drive Mode menu to switch your camera from taking a single photo when you push the shutter button to taking 3 photos of differing exposure instead. That's called exposure bracketing, and the setting you want might be called something like "BRK 2.0EV 3" which means take 3 photos, each separated by 2 EVs (2 full exposure "stops" of brightness). If you also have a choice between "C - Continuous" and "S - Single" choose C. That'll make your camera take all 3 photos with one press of the shutter button (you need to hold the shutter button down, which is why I recommend a remote shutter release). The first will be the normal "correct" exposure, the second will be 2 stops darker, and the third will be 2 stops brighter. If you don't have a Continuous setting, you'll need to click the shutter 3 times to take the 3 photos. My 3 photos using the steps I've described are the 3 photos below.   Take those photos and upload them into your PC, and go to a website like Online HDR Photo Stitcher, where you upload the 3 photos and let the web site combine them into an improved final single photo. If the web site I've linked to no longer works or hassles you to pay, use google to search for "HDR Merge Online" to find a different site. For my 3 photos above, the website I linked to made the following combined HDR image.  That result really beats the "single-best-photo" above. Notice how the church lights show the details from the first photo of the 3, whereas the ceiling shows the details of the 3rd photo. So congrats to you beginners on improving your low-light photos significantly without leaving Automatic mode or buying any software. But if you want results like the top photo on the page, read on to learn how I suggest an advanced amateur should shoot this scene. If you're an advanced amateur...... let me explain how I shoot HDR photography. Study the 5 images below which I took to create the high-quality image at the top of the page. First I set my camera to fully-manual mode, set the aperture to f/8, and set my camera's ISO to the base ISO for my camera (for me, that's 100). Then I set my shutter speed to whatever speed produces the brightest photo I can make without over-exposing any pixels at all. This is the crucial step, read that bold print again. On a camera that shows your histogram before shooting, you can achieve this by selecting a shutter speed such that the right edge of the histogram is down at the baseline, and rises just to the left of the right edge rather than right on that right edge. But on any camera, even one that shows your histogram before shooting, you can check your exposure by taking a test exposure and making sure no bright pixels are blinking when you review the photo with the over-and-under-exposure "blinkies" turned on. In my examples below, that exposure is the first one of the five below. It looks way too dark to your eye, but there is beautiful detail in the brightest areas, and we'll be replacing everything fainter than those bright areas with data from the other exposures. In my humble opinion, preventing over-exposure in the brightest highlights of an image is the key to getting a great HDR photo, so I encourage you to get this first exposure right by following my bold print suggestion at the start of this paragraph. After this first exposure, I just slow down my shutter speed by 2 stops (that's 4 times the exposure time, 6 clicks of the shutter dial on my camera). If the first photo was 1/15th sec, I switch to 1/4th sec (that's 1/15 times 4) and take another shot, the 2nd one below. Repeat again for the 3rd photo (1 second in my case), 4th photo (4 seconds) and 5th photo (15 seconds). I usually keep going until nearly everything is overexposed, or at least until all the shadows in the image are sufficiently brightened-up to be clearly visible. Looking at my 5 photos below, I maybe should have gone one step further in this image since there might have been more to pull out at upper-right and above the organ pipes by going to 60 seconds in Bulb mode. In general, you should just keep going further and further in lengthening your exposure until the shadows are brightly exposed. Don't worry that all the brights are blown out and ugly, these final exposures are just intended to capture the shadows sufficiently.   I combine my photos together (this is called Photo Merge ---> HDR) using Lightroom, but lots of software can do it. I find that modern Lightroom does a spectacularly great job with no effort at all on my part, and there's no need to try or pay for additional software. Within Lightroom I always tick the "Auto Align" and "Auto Settings" check-boxes. "Deghost Amount" depends on whether anything has moved between your exposures, such as people walking or leaves blowing in the wind. If there's no motion, set "Deghost Amount" to "None". If there's some motion, set it to "Low", "Medium" or "High" and see which result is best. If you use Lightroom or other paid software, you can combine as many images as you'd like into the final image. When I combine my 5 photos, I end up with this result (the same photo as shown at the top of the page). Even if I just use Online HDR Photo Stitcher to merge the 1st, 3rd and 5th of my 5 images together, I end up with the result below.  This is superior to the beginner method's results for two simple reasons. The first is that the spread between the photos used was 4 stops rather than only 2 stops (the max most cameras allow), and there's a lot more dynamic range in the church than a 2-stop-under and 2-stop-over image permits. But most importantly, we're controlling intelligently how the source images are made. We start with an image that includes the brightest highlights in the image without overexposing them. This is the faintest image that will be useful to us in our final merge. If we photograph anything fainter, it's useless since it adds no useful information to the merge. All that is useful is to expose brighter to gain details in the shadows, over and over and over again until even the shadows are overly-bright. But the key to success is to start your exposures with the bold print in the paragraph above, and increase exposure from there to gain details in the shadows and darks, then HDR-Merge all your exposures. Once you understand this manual technique starting with the brightest photo you can make without over-exposing any pixels at all, you'll be able to capture a great HDR image every time you attempt one, in a half-minute or less. |