Shockless White Balance

Still photographers new to video will soon notice that unwanted changes in exposure, focus, or white balance that occur while the video is being captured can be disconcerting. Sony takes care of the shifting white balance problem by providing a setting called Shockless White Balance, which is available only when the Still/Movie/S&Q dial is set to one of the two movie positions.

This setting determines how quickly white balance switches during movie shooting. You can choose:

• ■Off. White balance switches immediately if you change the WB setting during movie shooting.
• ■1 (Fast), 2 (Medium), 3 (Slow). The white balance shifts more smoothly, depending on the speed you select. Note that Auto White Balance (AWB) is not affected by this option, nor are changes to white balance specified using the Color Temperature/Filter setting.

The a7 IV provides many WB presets, each intended for use in specific lighting conditions. You can choose from Daylight, Shade, Cloudy, Incandescent (often called Tungsten by photographers), four types of Fluorescent (Warm White, Cool White, Day White, and Daylight), and Flash. However, the a7 IV also offers a method for setting a desired color temperature/filter as well as a custom WB feature.

The Daylight preset provides WB at 5,200K, while the Shade preset uses 7,000K to give you a warming effect that’s useful in the bluish light of a deeply shaded area. The chief difference between direct sun and an area in shade, or even incandescent light sources, is nothing more than the proportions of red and blue light. The spectrum of colors used by the a7 IV is continuous, but it is biased toward one end or the other, depending on the white balance setting you make.

However, some types of fluorescent lights produce illumination that has a severe deficit in certain colors, such as only particular shades of red. If you looked at the spectrum or rainbow of colors encompassed by such a light source, it would have black bands in it, representing particular wavelengths of light that are absent. You can’t compensate for this deficiency by adding all tones of red. That’s why the fluorescent setting of your a7 IV may provide less than satisfactory results with some kinds of fluorescent bulbs. If you take many photographs under a particular kind of non-compatible fluorescent light, you might want to investigate specialized filters intended to be mounted on your lens for use under various types of fluorescent light, available from camera stores, or develop skills in white balance adjustment using an image editor or RAW converter software program. However, you do get four presets for fluorescent WB with the a7 IV and one of these should provide close to accurate white balance with the common types of lights.

It’s when you find that AWB and the various presets simply cannot produce pleasing white balance in certain lighting conditions that you’ll need the other options (discussed shortly): use the white balance adjustment feature, set a specific color temperature, or calibrate the WB system to set a custom white balance.

Fine-Tuning Preset White Balance

After you scroll to any of the WB options (AWB, Daylight, Shade, etc.), pressing the right directional button reveals the White Balance Adjustment screen, with a grid, shown in Figure 5.10. This feature allows you to fine-tune the white balance by biasing it toward certain colors. Use any of the four directional keys to move the orange dot (cursor) from the center of the grid: upward to bias the WB toward green (G), downward toward magenta (M), right toward amber (A), or left toward blue (B). You can move the cursor seven increments (although Sony doesn’t reveal exactly what those increments are) in any of the four directions.

Naturally, you can also move the orange dot to any point within the grid: toward amber/magenta, for example. While biasing the WB, examine the scene in the LCD or viewfinder preview display; stop making adjustments when the white balance looks fine. Tap the shutter release to escape from the WB settings adjustments. Let’s look at the options in more detail:

• ■Cooler or warmer. Pressing the left/right directional buttons changes the white balance to cooler (left) or warmer (right) along the blue/amber scale. There are seven increments, and the value you “dial in” will be shown in the upper-left corner of the screen as an A-B value (yes, the labels are reversed from the actual scale at the right side of the screen). The red dot will move along the scale to show the value you’ve selected. Typically, blue/amber adjustments are what we think of as “color temperature” changes, or, “cooler” and “warmer.” These correspond to the way in which daylight illumination changes: warm at sunrise and sunset, very cool in the shade (because most of the illumination comes from reflections of the blue sky), and at high noon. Indoor light sources can also be cooler or warmer, depending on the kind of light they emit.
• ■Green/magenta bias. Press the up/down buttons to change the color balance along the green (upward) or magenta (downward) directions. Seven increments are provided here, too, and shown as vertical movement in the color balance matrix at the right of the screen. Color changes of this type tend to reflect special characteristics of the light source; certain fluorescent lights have a “green” cast, for example.
• ■Either or both. Because the blue/amber and green/magenta adjustments can be made independently, you’re free to choose just one of them, or both if your fine-tuning requires it.
• ■Never mind. If you want to cancel all fine-tuning and shift back to neutral, just press the MENU button to cancel. The orange dot in the color chart will be restored to the center position.

Setting a Custom White Balance

If you often shoot in locations that are illuminated by artificial light of unusual colors, the best bet is to set a custom white balance. This calls for teaching (calibrating) the WB system to render white as white under a specific type of illumination. When white is accurately rendered, other colors will look accurate as well. You can use this feature under more common types of lighting too; it’s very useful under tungsten lamps, for example, when the Incandescent WB option does not adequately correct for the amber color of the light. Custom WB is the most accurate way of getting the right color balance, short of having a special meter that gives you a precise reading of color temperature. It’s easy to do with the a7 IV. Just follow these steps:

• 1.Navigate to Exposure/Color > White Balance > White Balance or use the Function menu.
• 2.Use the directional buttons or the control wheel to scroll up/down through the list of white balance options until you reach Custom 1, Custom 2, or Custom 3 registers. Highlight the custom white balance register you want to use and press the right directional control.
• 3.Select the Set icon, as shown in Figure 5.11, left. These are white balance memory register “slots” you can use to store customized white balance settings.

• 4.Press the center button. The display shown in Figure 5.11, center, appears. Point the camera at a white or gray object (such as a sheet of white paper or a gray card) large enough to fill the small orange square that’s displayed in the center of the frame. Your target must be in the same light as the subject you plan to photograph, not in some entirely different part of the scene where the illumination is different.
• 5.Press the center button. The target (such as the sheet of white paper) that you had aimed at, as well as the custom white balance data, appears on the LCD or EVF screen. (The image is not recorded to the memory card.)
• 6.The white balance of the target you photographed will appear at the bottom of the screen. (See Figure 5.11, right.) You can press the right directional control to adjust the white balance further using the screen shown earlier in Figure 5.10.
• 7.Press the center button to confirm and return to the live view on the LCD. Henceforth, you can select that Custom register to load a particular set of white balance parameters. You can use the White Balance Adjustment screen at any time to further fine-tune the balance.

Setting White Balance by Color Temperature

If you want to set a specific white balance based on color temperature, choose C. Temp/Filter in the White Balance menu and press the right button. You’ll next see a display of color temperatures arrayed along the bottom of the screen. Press the right button a second time to view an adjustment screen similar to the one shown in Figure 5.11, but with a scrolling list of color temperatures displayed. Here’s how to use this feature.

• ■Change color temperature. Rotate the control wheel on the camera back to select a specific color temperature in 100K increments, from 2,500K (a level that makes your image much bluer, to compensate for amber illumination) to 9,900K (a level that makes images much redder to correct for light that is extremely blue in color). The live preview changes as you scroll to give you an indication as to the white balance you can expect at any K level. If you have a color temperature meter accessory, or reliable tips that guide you in making the optimal setting, this WB feature will be particularly useful. Even if you don’t have that accessory or useful information, you may want to experiment with this setting using the live preview, especially if you are trying to achieve creative effects with color casts along the spectrum from blue to red.
• ■Fine-tune the color temperature. In addition to color temperature, you can press the right directional button to change the blue/amber or green/magenta bias, exactly as described earlier and shown in Figure 5.10; move the cursor in any direction with the directional keys. If you change your mind, press the MENU button to cancel the bias adjustments you’ve made.
  • This feature corresponds to the use of CC (Color Compensation) filters that were used to compensate for various types of lighting when shooting film. When you use C. Temp/Filter, the color filter value you set takes effect in conjunction with the color temperature you set. In other words, both of these settings work together to give you very precise control over the degree of color correction you are using.

Note that the color temperature you set here is not affected by the Shockless White Balance option discussed earlier.

Interval Shooting Checklist

Interval photography is not a technique where you can get your best shots by winging it. The shooting process can be—and usually is—lengthy, so you don’t want to spend two hours driving to a location, then 10 minutes or 10 hours capturing a sequence to discover poor planning has ruined your final results. This section provides some tips for preparing for your interval or time-lapse shooting session.

• ■Know your subject. If you plan to shoot a sunset, make sure you know exactly when the sun will set, so you can arrive early enough to set up your equipment and adjust your camera. You can Google the necessary information, but apps for Android and iOS devices called PhotoPills and The Photographer’s Ephemeris can tell you exactly when a celestial event will occur, and even provide you with a map that will help you calculate your best location. If, say, you want to shoot the sun setting behind a lighthouse, the app will tell you the precise spot to stand, and when. If you’re capturing the ebb and flow of tides, you’ll need to know the time of high and/or low tides at a specific location. Don’t forget to scout the location ahead of time, too.
• ■Use a sturdy tripod. If you don’t have a sturdy tripod, take along an empty sack (I use the lightweight mesh bags that oranges come in), fill it with rocks when you arrive at your location, and hang it from the center column of your tripod to add ground-hugging weight. Successful interval photography calls for a camera that doesn’t move between shots so the successive images show what has changed between intervals. That’s not to say that some interesting photos can’t be taken by panning and/or moving the camera between intervals. You want to avoid unwanted movement, and save intentional movement for experimental photography.
• ■Have a fully charged battery or another power source. Interval photography drains the a7 IV’s batteries at an alarming pace. For long sequences, you’ll want to use a charged battery or external power. Turn off picture review to reduce power consumption.
• ■Make sure the camera is protected from the elements, accidents, and theft.
• ■Long Exposure Noise Reduction disabled. When Long Exposure NR is enabled, the a7 IV takes an additional dark “comparison” frame using the same exposure time so sensor noise can be removed. Your a7 IV disables Long Exposure NR during interval shooting.
  • Think about it. If you’re taking a 20-second exposure at intervals of less than 40 seconds, you would not want the camera to follow the original shot with an additional 20-second dark frame. That’s true whenever the total time required for the original/dark frame exposures is longer than your interval. So with Long Exposure NR disabled, you’ll have to accept a little noise to maintain your shooting rate.
• ■Focus manually. There aren’t many common interval-shooting situations in which I’d want to have focus change from shot to shot. Perhaps you’re expecting a herd of deer to cavort through your garden and would like the camera to attempt to focus on the nearest beast. Most of the time, however, consistent manual focus is best. Choose whether you want to focus on the foreground, middle range, or background, and set your focus point there. If you’re capturing photos of, say, a flower opening, use the Focus Magnifier to help you choose the precise plane of focus. Depth-of-field can be used creatively with small apertures (to increase the range of sharpness) or large f/stops (to allow selective focus).
• ■Manual exposure—or not? If you set exposure manually, each picture you take will use the same ISO, f/stop, and shutter speed setting. If the light remains even during the sequence, that can be a good thing. If the light changes (say, throughout a day), that can be bad, or distracting, or, in some cases, add a certain desirable look. Your a7 IV’s Interval Photography setting for Autoexposure Tracking Sensitivity can be used to fine-tune exposure. If autoexposure is active, you can specify a fast response to changes (High), or opt for slower adjustments using the Medium or Low sensitivity settings.
  • Know that quick changes in exposure can be distracting, especially when combining shots into a time-lapse movie. If you want to see dramatic light shifts as your scene lightens or darkens, use Manual Exposure and set the shutter speed, ISO, and aperture to give the correct “normal” exposure.
• ■Choose an interval. The time between each shot can be important. If you wait too long, you may miss an important event; choose a very brief interval, and you can end up with too many photos that are almost identical and lacking in the time-lapse effect. The interval is especially important if you intend to combine your shots into a time-lapse movie. With, say, slow-moving clouds, one shot every 10 seconds may produce a majestic march across the sky; fast-moving clouds can require taking one picture every three to five seconds. Sunsets work best with 30-second intervals; I get good results using 60-second gaps between shots when shooting the stars.
  • To add Charlie Chaplin-like movement to pedestrians, one shot every second or two does the job. (Fun fact: The cameras used for Chaplin’s comedies were hand-cranked at frame rates of around 14 to 16 frames per second; when projected at the eventual standard of 24 fps, the motion was sped up. To compensate, Chaplin later had some frames duplicated in printing to simulate the 24 fps rate—while the motion was less frenetic, it became jerkier in the process.)
• ■Choose number of shots to capture. For practical reasons, you need to know how long it will take to capture your sequence. When you’ve chosen an interval and number of shots, the a7 IV displays the total elapsed time, but common sense will tell you that if you are shooting one frame every 10 seconds (six per minute), if you want to capture 60 minutes’ worth of action, you’ll need to take 360 shots. Conversely, if you plan to convert your images into a movie, you’ll know that, at, say, 30 frames per second, your 360 images will provide a movie only 12 seconds in length! Obviously, for time-lapse movies, you’ll probably be capturing a lot more than 360 images; the a7 IV allows as many as 9,999 frames—about 5.5 minutes’ worth at 30 fps.
• ■Choose your start time. Use this setting to delay the start of image capture, from 0 minutes, 0 seconds (begin immediately) to 99 minutes, 59 seconds. While you may want to begin shooting immediately, you should still set a short delay (say 20 seconds) as a start time so the camera can settle down in its tripod perch. If you want to begin capturing an event, say, a sunset, in 10 minutes, you can specify that much of a delay, and spend the intervening time setting up other cameras, performing other tasks, or chatting with your companions about how great your photos are going to be.

Settings Recap

I detail all major settings for the Interval Shooting Functions in Chapter 6. Here’s a quick preview:

• ■Interval shooting. Choose On or Off to enable/disable the feature. You’ll want to keep this setting at Off until you are ready to begin interval shooting.
• ■Shooting start time. Use this setting to delay the start of image capture, from 0 minutes, 0 seconds (begin immediately) to 99 minutes, 59 seconds.
• ■Shooting interval. Specify how often an image should be captured. If you need an interval longer than 60 seconds, you’ll need to purchase an external intervalometer.
• ■Number of shots. This setting determines the total number of exposures in a time-lapse sequence. You can choose from 1 to 9,999 shots. A message at the bottom of the screen will display how long it will take to capture the number of shots you specify using the shooting interval you’ve chosen.
• ■Autoexposure Tracking Sensitivity. Select from High, Mid (Medium), or Low sensitivity.
• ■Shutter Type in Interval. Choose On or Off. If you select On, the a7 IV will operate silently, which allows capturing your sequence in “stealth” mode if you need it. Shutter type is set to Electronic Shutter by default.
• ■Shoot Interval Priority. When shooting sequences using Program or Aperture Priority modes, the a7 IV will adjust the shutter speed to provide the correct exposure. That may result in a shutter speed that is longer than the specified interval. Choose Off for this setting and the a7 IV will go ahead and expose for the correct amount of time, skipping the shot that would have taken place.
  • Choose On, and when another interval exposure is due, the a7 IV will terminate the previous shot (underexposing it) and begin the next one on schedule. You might use the On option if you feel that just dropping the poorly exposed image from the sequence produces the best series. You may be able to avoid the underexposure by activating Auto ISO Sensitivity, and selecting a minimum shutter speed that is shorter than the interval time. In that case, the camera will increase the ISO setting (if necessary) to produce the correct exposure using the automatically selected shutter speed. The chief drawback is that increasing the ISO automatically may also increase the amount of noise in your image. Significant changes in graininess may detract from your sequence or time-lapse movie.

After you’ve made your settings, double check to make sure the Interval Shooting entry is set to On, then exit the menu. When you’re ready to begin, press the shutter release button down all the way. You’ll see a message that the camera is in Standby mode, and notified when the first and all subsequent images are captured. A display at the lower-left corner of the screen shows the interval and number of shots taken/in the series. Auto Review is disabled, so you will not see each picture as it is captured.

Take care, because with short intervals, the camera can get hot over an extended period of time. As shooting begins, you can use a previously defined function key to activate one of the following functions: Autoexposure Hold, Spot Autoexposure Hold, Register AF Area Hold, or Auto White Balance Hold. The function invoked will remain active during your sequence. You can cancel an interval sequence by pressing the shutter release again.

Viewing Your Interval Sequences

You can view your sequences as if they were a time-lapse movie in the camera. You can also create an actual time-lapse movie from your photos; I’ll describe that in the section following this one. To view your sequence as a movie in the camera, just follow these steps:

• 1.Choose speed. In the Playback > Viewing group, you can choose Playback Speed for Interval and choose a speed from 1 (slow) to 9 (fast).
  • •At the slowest speed, the a7 IV will display each frame you took one after the other, so you’ll see every image captured. The apparent speed of motion will be determined by length of the interval between each frame, and, to a certain extent, the size of the image file. That is, motion captured with larger intervals will appear to be moving faster, so sequences shot at 10-second intervals will seem “slower” than those taken at 20-second intervals. In addition, you may need to take into account how many images can fit into the camera’s buffer as they are displayed. Images captured in Large JPEG Extra Fine format may take longer to display than those captured in Small JPEG Standard format. In most cases, the difference in speed will be much less than the difference caused by the interval.
  • •At faster speeds, the a7 IV “skips” frames, playing back every second, third, fourth, etc., image, producing faster apparent motion, but also resulting in a jerkier appearance. In effect, faster playback speeds decreases the interval between shots.
• 2.Select Continuous Playback. First scroll to the group of continuous shots you want to view, then navigate to Playback > Viewing > Continuous Playback. Press the center button. The camera will display the images in order quickly, at the speed you’ve specified.

Time-Lapse Movies

It’s easy to convert your sequence of images into a time-lapse movie. All you need is the Viewer module from the free Imaging Edge software suite. It can quickly convert your individual frames into a Full HD (1920 × 1080) or Ultra HD (3840 x 2160) MP4 video clip. Just follow these steps:

• 1.Deposit sequence in a folder. Copy all the frames you want to use to a new folder on your computer. You’ll find it easier to select them if they are located in their own folder. Your images can be RAW or JPEG files.
• 2.Launch Viewer. The left-hand panel displays your computer’s directory tree. Select the drive and folder that contain your files.
• 3.Sort files. In the Viewer’s Tools menu, choose Sort > Sort by Date and Time Taken.
• 4.Select All. Press Control-A (Command-A on a Mac) to select all the files in the folder. Note that you must have at least 15 images to create a time-lapse movie.
• 5.Commence processing. In the Tools menu, choose Create Time Lapse Movie (see Figure 5.12, left).
• 6.Select options. The screen shown at right in Figure 5.12 appears. There are four adjustments you can make.
  • •Output method. In general, you can leave the Apply Each RAW File’s own settings to each RAW file marked. The app will use the parameters you specified in the camera for white balance, etc. If, for some reason, the RAW settings differ among your files, you can apply the parameters for an image you select (say, the first one in a sequence) and apply them to all subsequent frames.
  • •Save Format. Here you can choose a color space and/or compression level for your video. I recommend going with the defaults. If you needed an extra-high-quality movie, you could change to Compression Level 1.
  • •Save To. Select a folder to save your video to, and specify a filename. You can use the original filename or select various combinations of Date Taken, Date and Time Taken, and a 5-digit number generated by the program.
  • •Trimming. Here you can specify the aspect ratio of your movie. For greatest compatibility with other videos you may want to add or intercut, choose the 16:9 ratio standard for HD movies. You can also select 4:3, 3:2, or 1:1 aspect ratios, or tell the program to use whatever proportions the a7 IV was set to when the stills were captured.

• 7.Click Next. If you’re working with JPEG still photos instead of RAW images, the program will suddenly come to the conclusion that no further processing (adjusting white balance and so forth) is required, and tell you “Some of the selected images will not be processed because they do not have to be developed or are in unsupported formats.” Ignore this message if Sony’s programmers haven’t corrected this bug in your current release of the Imaging Edge software. The program will tell you which files it skipped (basically, all your JPEG images), and invite you to click Next once again to proceed.
• 8.Edit settings. The Edit screen, shown at left in Figure 5.13, appears. It has several options that you can reveal from drop-down lists.
  • •Time Lapse Setting. This panel is shown at far left in Figure 5.13. You can adjust playback speed from 1X to 16X, and view the total time recorded, although with the most recent copy of Viewer that I used, the speed didn’t seem to vary as described. Look for a fix in a future update of the software.
  • •Music. Allows you to select music tracks on your computer, and to download additional music from Sony’s website (see Figure 5.13, center right).
  • •Music Settings. Here you can balance the volume of the music you added with the soundtrack already recorded on your video. That allows you to have the music predominate, fade in, fade out, and/or loop continuously during playback (see Figure 5.13, far right).
• 9.Save your work or produce a movie. You can stop working at this point and return to this point by clicking Save Project. It’s a good idea to do this, just in case your final video needs to be tweaked and redone. When you’re ready to produce your time-lapse clip, click Next.

• 10.Specify filename, folder, and format. When the Save screen shown in Figure 5.14 appears, you can type in a new filename for your movie, specify a different directory to save your file in, or choose one of three movie formats:
  • •4K. This choice produces a 2160p/30 fps MP4 video clip in XAVC S format. (You can read about various video formats and parameters in Chapter 10.) You’ll need a 4K-compatible display to view this UHD movie.
  • •Good for Viewing on a TV or Computer. This is usually your best choice, as it delivers a 1080p/30 fps MP4 file in AVC format, viewable on any HDTV or modern-day computer screen that can handle Full HD.
  • •Smaller Size for Easier Uploading. Choose this to create a Standard HD 720p/30 fps MP4 clip in AVC format. This creates a much smaller file that can be transferred over the Internet, and uploaded to YouTube more easily.
• 11.Click Save. The program will create your video clip and store it in the specified folder. The process may take some time, but a progress bar (seen at center in Figure 5.14) will keep you updated.

Star Trails

Star trails (see Figure 5.15) are another great application for interval shooting. As I noted earlier, you can shoot the night sky using long exposures with your a7 IV mounted on a tripod. However, because of the rotation of the Earth, longer exposures will record the apparent motion of the celestial objects through the sky, producing a light trail. If you use a very, very long exposure, the light trail will record as continuous streaks, centered around the Polaris (the North Star) in the northern hemisphere and Sigma Octantis (which is, unfortunately, too dim to be easily seen with the naked eye) in the southern hemisphere.

Such long exposures can result in excessive noise and sensor overheating, so it’s more common for photographers to take a series of individual exposures and combine them to produce a single star trail image. If you want your stars to appear as reasonably sharp points, you’ll need to keep the exposure short enough that their movement in the sky isn’t apparent. Fortunately, there’s a simple formula you can use to calculate that exposure time, the “500 Rule.” Divide 500 by the focal length of your lens to determine the longest exposure (in seconds) before stars start to produce a blurred trail. For example, with a 50mm lens, the longest exposure would be 10 seconds (500 divided by 50). Capturing the complete canopy of stars generally requires a wider viewing perspective. With a 16mm wide-angle setting exposures could be as long as roughly 30 seconds.

For Figure 5.15, I set my camera to ISO 200, and used a basic exposure of 30 seconds at f/5.6. I selected an interval of 32 seconds and 170 total exposures, which totals about 90 minutes. Then, I followed these steps, using Photoshop:

• 1.Transfer files to a folder. Select a folder on your computer, and copy all your files to that location.
• 2.In Photoshop. Choose Files > Scripts > Load Files into Stack.
• 3.Browse to folder. Click the Browse button and navigate to the folder where your images are stored.
• 4.Click OK. Photoshop will create a file with one layer for each of your captured images.
• 5.Select All layers. Then click Layer Blending Options from the Layers palette, and choose Lighten.
• 6.Flatten image. You’ll want to flatten your image (the multi-layer file will be huge!). You’ll end up with an impressive star trail image.