Please note that this page describes the steps to capture multiple exposures with your camera with the intent of merging them into a single HDR image. It does not describe the merging or post-processing steps I’ll say that I use Adobe Photoshop Lightroom and Photomatix Pro. A tutorial is available here: Sumptuous HDR.
The Sony NEX-7 offers automatic exposure bracketing (AEB) that allows you to take up to three images at a time with the camera adjusting the exposure by up to 3 stops in between each picture. In my opinion, 3 Exposure Value (EV) stops between each frame is too much to ensure a smooth transition when merging the images. Two stops of exposure between frames is good, and three images at 2 EV spacing should provide plenty of data to work with for at least 90% of the scenes you wish to capture in HDR.
Three images at 2 EV spacing would give you files with the following exposures:
-2 EV | 0 (balanced) EV | +2 EV
Again, these three image files should be all you need to capture the dynamic range of most of the scenes you’ll be shooting.
This camera has a feature to shoot HDR images automatically in-camera. It will take the three images at different exposure values and merge them for you and produce a single image. I have never once used this feature and have no plans to ever do so. For one thing, it requires you to shoot JPEG’s, and I always shoot RAW images. More importantly, it takes the fine-tuning of the merging process out of your hands and relies on the camera’s programming. To me that’s a bad thing, and, again, I never use the in-camera HDR functionality.
On Shooting Hand-Held
The Sony NEX-7 is a mirrorless camera which means it is smaller and lighter than a DSLR. The lenses are also smaller and (for the most part) lighter. It still has an APS-C sensor that delivers 24 megapixels of resolution. That’s the same sensor size as Nikon’s DX line of DSLR’s but in a much smaller overall package. This makes the Sony NEX system an excellent camera for walking around town or hiking the trails. As such, it would be a shame to burden yourself with a tripod.
Ordinarily I’d strongly recommend shooting AEB sets for HDR with the camera mounted firmly on a sturdy tripod. We’ll be merging multiple shots of the same scene into one image, so you need those multiple shots to be as close to perfectly aligned with each other as possible. However, modern HDR software (especially Photomatix Pro 5) is very good at aligning the images for you. A little movement between frames is no longer a huge issue.
Besides a steady shot, there is another benefit to shooting on a tripod. You can use slower shutter speeds and lower ISO settings. Image noise (randomly spaced and colored speckles on the picture) is still an issue with HDR. For whatever reason, the HDR process accentuates any noise that is present in the original captures. Admittedly, the NEX-7 is not the greatest camera when it comes to noise. You’ll pretty much never want to go higher than ISO 1600, and even that is pushing it. With a tripod, you can use lower ISO settings and get the correct exposure by slowing down the shutter speed. Generally speaking, you want the shutter speed to be, at a minimum, the inverse of the focal length. At a 60mm focal length, for example, you’d want the shutter speed to be at least 1/60 of a second. The Sony NEX-7 will adjust the ISO automatically to get that speed and even take the current focal length into account. You can turn off auto-ISO, use a tripod and get cleaner images if you want to. Of course, with slower shutter speeds, you run the risk of having movement within the scene. This is always true of slower shutter speeds.
I don’t worry about high-ISO noise though. Software like Adobe Photoshop Lightroom and Imagenomic Noiseware do a very good job of reducing unwanted noise during post-processing. Another reason I don’t worry about noise while shooting for HDR with the Sony NEX-7 is because I typically use the camera in good light. If you want to shoot all of your HDR images with the Sony NEX-7 (indoors with dim light, at night, etc.), you’ll need to use a tripod at least some of the time.
I have never put my NEX-7 on a tripod. It’s a great walking-around camera, and I don’t want to burden myself with extra gear. For HDR, I only use this camera in fairly bright, daytime light where I can use fast enough shutter speeds. If lighting conditions mean I need a higher ISO than 1600 to use an acceptable hand-held shutter speed, I use a tripod and a different camera (like the Nikon D800).
Setting Up the Camera
There’s only one thing that needs to be setup ahead of time, and it is a set-it-and-forget-it kind of option that you only need to do once. You have to configure the camera such that the AEB series will use 2 EV spacing between each shot. There are other EV spacing options, but I don’t find them as useful for HDR work.
On the back of the camera, press the Control Wheel on its left side to bring up the Drive Mode options. From the Single Shooting option, rotate the Control Wheel counter-clockwise for two clicks until one of the BRK C options is highlighted. While this option is highlighted, press the Option button (which is called Soft Key B and is the small, circular button below and to the left of the Control Wheel) to bring up the options for bracket increments. Rotate the Control Wheel until BRK C 2.0EV is highlighted and press the center button to select. The camera is now set to use 2 EV spacing when shooting bracketed exposures. Personally I leave it at this setting all the time.
While we’re setting up the camera, there are a couple other things you might check even though they are not strictly related to HDR shooting. Press the Menu button (small button slightly above and to the left of the Control Wheel) on the back of the camera and rotate the Control Wheel until Setup is selected. Press the center control button to enter the Setup menu. Rotate the Control Wheel until Color Space is highlighted and make sure it is set to AdobeRGB. Immediately under Color Space, ensure that SteadyShot is turned on.
I’ll also mention that the controls on the Sony NEX-7 can be customized. Just about all of the buttons and dials can be configured to do things differently than the defaults. For the following instructions I refer to the factory default settings.
Shooting an AEB Set for HDR
Set ISO to Auto: With the camera on, simply rotate the Control Wheel on the back of the camera counter-clockwise until AUTO is highlighted. Be careful not to press the Control Wheel on any of the sides because that might take you into a different setting; just rotate it. Once AUTO is highlighted, you can press the center button (which is called Soft Key C) or partially depress the shutter release button to exit the ISO settings.
Set the Drive Mode to Bracket: Cont.: 2.0EV: Press the Control Wheel on the back of the camera on its left side to bring up the options for Drive Mode. From the Single Shooting option, rotate the Control Wheel counter-clockwise for two clicks until BRK C 2.0EV is highlighted. Once BRK C 2.0EV is highlighted, you can press the center button (which is called Soft Key C) or partially depress the shutter release button to exit the Drive Mode settings. If you don’t see an option for BRK C 2.0EV please see the Setting Up the Camera section above to learn how to change the EV spacing increments. The camera is now set to shoot an AEB set of images for HDR.
When we shoot for HDR, we’re doing so because the camera wouldn’t be able to handle the full dynamic range of the scene with just one exposure. There’s too great a difference between highlight and shadow areas. With this in mind, not every scene we come across is appropriate for HDR treatment. You could leave your camera set to shoot AEB sets all the time, but with 24 Mp per file, that would eat up a lot of hard drive space over time. Also, how would you know which sets are truly meant for HDR? Fortunately, the Sony NEX-7 makes it easy to switch between bracketing and taking a single shot. Simply press the Control Wheel on its left side to access the Drive Mode options and rotate the wheel two clicks counter-clockwise to highlight the bracketing option or two clicks clockwise to return to single shooting.
When you’ve found your scene to capture, and the camera is set to shoot a bracketed exposure set, just aim, compose and press the shutter release button half way to focus. Take a deep breath and steady yourself (while properly holding the camera of course) and press (don’t stab) the shutter release button down all the way. Hold the shutter release button down slightly longer than normal and listen for all the shutter clicks to happen. And then that’s it; you’ve captured a bracketed set of images at different exposures that are ready to be merged for HDR processing.
This is a quick note to let you know that I import all of my images into Adobe Photoshop Lightroom. The first thing I always do is group each series into its own stack. Once I decide which exposures to use for the merged image (because I don’t always need to use all of the exposures captured), I export the files to Photomatix Pro. After trying other HDR applications, I almost never use anything but Photomatix at this point. After merging and creating a new image file (it comes back as a TIFF), I process the image in Lightroom. Once in awhile I feel the need to move into Photoshop-proper for some final touches.
A full description of my HDR post-processing techniques can be found here:
Some Examples Using the Sony NEX-7:
All of the following images were made using the process described above, which means they were all shot hand-held.