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Showing off with the Nikon D1, shooting fireworks  
Saturday, January 1, 2000 | by
Today's DigiNews is all about shooting fireworks with an NC2000e, DCS3 or DCS 520/D2000. Independence Day fireworks displays taking place across the United States this weekend will kick off at or past deadine for many news organizations, making a digital camera the tool of choice. Digital fireworks photos can look great, but only if carefully shot, acquired and pre-pressed. Follow these guidelines for best results July 4th:

ISO and Exposure
Set your camera at ISO 200, only ISO 200 and nothing but ISO 200. Keeping the shutter open for several seconds to catch multiple bursts causes a boost in image noise and, in the case of the DCS 520/D2000, causes strange dropout pixels to appear in dark areas of the frame. This noise increase is an unfortunate and unavoidable property of digital cameras, wherein blue channel guck in particular is emphasized when the CCD is kept active for longer than about a 1/4 of a second.
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Expose for the highlights. The DCS 520/D2000 makes this easy, thanks to its saturated highlights indicator. Set the exposure so that white light bursts, which will be the brightest, show only a few small areas of the image blinking to indicate they're blown out. Make sure the LCD screen brightness slider is set about in the middle of its range too.

Forget about the histogram, which will be heavily skewed towards the dark dark end of things and all but impossible to interpret. NC2000e and DCS3 users, your approach is a little less scientific - bracket, alot, especially if this is your first fireworks display shot on digital.
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Keep the shutter open as short a time as possible. As mentioned above, the longer the shutter opening the greater the noise buildup. The NC2000e and DCS3 produce images with substantially less noise than the DCS 520/D2000 when exposures are in the 10 second range, but images from either camera will tend to be noisy, especially if the sky is a deep blue, not black. Keep the shutter speeds between 2 and 10 seconds, and the aperture between 8 and f11, for best results. Some photographers like to shoot fireworks on Bulb, covering and uncovering the lens as needed to catch large bursts. This approach is fraught with danger because of the noise buildup problem and is not recommended, especially with the DCS 520/D2000. Colder temperatures help temper the accumulation of visible noise in the CCD, so if you have an opportunity to shoot 4th of July celebrations from, say, 14,000 feet up Alaska's Mt. McKinley, go for it.

Just prior to the show, shoot a series of time exposures in increments that correspond to the shutter speeds you intend to use during the show, but with the lens and eyepiece completely covered (and the camera at your intended shooting ISO too). In other words, if you plan to keep the shutter open 2, 5, and 10 seconds at a time, shoot three frames at 2, 5 and 10 seconds with the eyepiece shutter closed and something opaque over the lens. Treat these three frames like the treasured family pit bull, because later you're going to enjoy watching them devour noise pixels in your fireworks photos.

Colour
The DCS 520/D2000 more than compensates for its noisiness with excellent colour rendition of fireworks' multi-coloured bursts. Expect fireworks photos from this camera to have great saturation and pleasing colour - red bursts will look red, green bursts will look green, etc. Forget about setting a custom white balance; lock the camera on the Daylight setting, which will give good colour and minimize the visibility of blue channel noise. NC2000e and DCS3 users won't be quite as happy - fireworks photos from these cameras don't show nearly the vibrancy or colour variation, with most bursts having somewhat of a white or magenta/red glow (see the NC2000e photo further down this page and you'll see what I mean).
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To achieve the great colour that the DCS 520/D2000 offers, be sure to shoot with the anti-aliasing filter tucked into place behind the lens. It will maximize the richness and accuracy of the colour while minimizing colour fringing and artifacting. The Tiffen Hot Mirror Filter is a poor substitute in this case. Though it offers similar colour improvements, it does nothing to limit colour artifacting, which is difficult to clean up after the fact in Photoshop. At least, not without causing a loss of saturation and unwanted colour shifts. NC2000e and DCS3 photogs will have to live with the artifacting, but can definitely expect more pleasing colour and greater colour variation in fireworks photos shot with the Tiffen Hot Mirror filter.
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Even more important is how NC2000e and DCS3 images are acquired.For the most pleasing reds and the greatest colour variation, I swear by the Portrait setting in v5.01 plug-in for Mac (v5.02 TWAIN for Windows). It applies industrial-strength magenta-fighting power to any image it acquires - too much for daylight photos, unless you like green people, but for fireworks it's definitely a good place to start.
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Photo Mechanic/AP Viewer's Mixed Light setting is also worth a look, as is Photo Mechanic/AP Viewer itself if you haven't tried it ( a fully-functioning demo of this Mac-only software is available for download). Click balancing is tricky, so I recommendyou start on the Daylight setting and work from there. Successive Kodak plug-ins, and Photo Mechanic, offer different colour, contrast and brightness characteristics, so don't be afraid to experiment if you have the time. At the very least, experiment the next day with some of your saved raw files, and you'll have a better idea of how to acquire NC2000e and DCS3 fireworks pics the next time around. For more information on the importance of the acquire step check out Getting the Best Colour from Your Digital Camera Plug-in, available in the pixelzone.

Remember to acquire the blank frames you shot prior to the show, along with your selections. And be sure to acquire them in the same plug-in at exactly the same setting. To keep them straight, I recommend you immediately save them as Photoshop format files with file names such as "Blank 2 second frame."

Pre-press
Digital noise removal is the first order of business, and is best done before the image is JPEG compressed and transmitted. Significant blue channel crap causes the JPEG algorithm to wheeze and sputter, resulting in whoppingly larger files (think longer transmission times) and JPEG artifacting in the form of detail loss. Fortunately, it's relatively easy to remove this noise in Photoshop, with the help of a simple but powerful Photoshop technique and either Quantum Mechanic or its simplified-interface sibling, AP Camera Filter QM.A fully-functioning demo of Quantum Mechanic is available for download from the Camera Bits website, so be sure to install it into Photoshop before the night of the 4th, and coax your boss into buying it or the AP Camera Filter QM shortly thereafter.

Once you've edited your photos, make a quick trip back into the plug-in and make note of the shutter speeds of the keepers. If the first one you're preparing for transmission is a 10 second, high-noise doozie, identify its corresponding blank 10 second frame from those you shot prior to the show. If you took my earlier advice, look for the photo called "Blank 10 second frame" and you won't go wrong. Then, perform the following steps:

1 Ensure that the 10 second fireworks frame is frontmost. Choose Apply Image from the Image menu. The Apply Image dialog will appear.

2 Configure Apply Image as shown at right. The Source should be the blank frame, and the Target the fireworks frame.

3 Click OK. If you've setup Apply Image correctly, the noise and drop out pixels in DCS 520/D2000 photos in particular will melt away before your eyes!

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Why does this work? Simple.The blue noise and drop out pixels that appear in long exposure photos aren't randomly scattered about the frame, though it might appear that way. In fact, their position and intensity is nearly identical from frame to frame at a given shutter speed and ambient temperature. That means that Apply Image can be employed to"subtract" all the noise and drop out pixels found in the blank frame from the fireworks frame, resulting in a much cleaner photo with no loss of detail in image content. View before (423K) and after (386K) versions of a 10 second DCS 520 fireworks photo that has been zapped as described. To force pictures to download to your Mac's hard drive (instead of opening in your web browser), option-click the link, then choose the download to disk option. Windows users, right-click then select the same.

Apply Image will remove most but not all unwanted noise. To further knock down blue channel muck in particular, DCS 520/D2000 users should next use Quantum Mechanic (and Quantum Mechanic only, especially if you take my advice and shoot with the anti-aliasing filter in place). Quantum Mechanic offers greater control over several key noise-zapping parameters, while AP Camera Filter QM's hard-wired presets will tend to remove too much red saturation in particular. The image at right shows a recommended configuration for noisy fireworks photos. Adjust only the Blue Chrominance up and down as needed, probably in the 3-5 range (or 5-10 range if you don't use the Apply Image technique).

NC2000e and DCS3 photos will need both blue channel noise and colour artifact removal. Again, assuming that the Apply Image technique has been used, try either the Low or Medium settings in the AP Camera Filter, or nearly the same settings as shown at right in Quantum Mechanic, except hike up the Red Chrominance value to the 1-3 range. Blue channel noise won't be as much of a problem as it is with the DCS 520/D2000 (assuming you shoot at ISO 200 and don't underexpose), so the Blue Chrominance range will be closer to 2-4. Experiment with the Chrominance sliders a bit, watching out for unwelcome saturation loss and colour shifts in particular.

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Note: You may be scratching your head over the fact that the DCS 520/D2000 produces noisier images than the NC2000e and DCS3. After all, the newer camera has been touted as having improved noise characteristics. And it does, in most shooting situations, besting the NC2000e and DCS3 in the 1/8000th to about a 1/2 second shutter speed range. But when the shutter is held open longer than that visible noise increases much faster in the DCS520/D2000 than it seems to in the NC2000e and DCS3. Go figure.

Do not sharpen the image in RGB, or prior to transmitting. Doing so will only enhance the visibility of noise. NC2000e and DCS3 photos will sharpen up best by applying unsharp masking in the Luminance channel in Lab colour mode. Doing so sharpens image detail without sharpening any noise not zapped by Quantum Mechanic or AP Camera Filter QM.

DCS 520/D2000 photos, especially ones shot at closer to 10 seconds in warm temperatures, will have drop out pixels (Bob Deutsch of USA Today calls this phenomenon digital dust) absolutely filling the dark areas. Those aren't stars, they're a downside to this camera's essential wonderfulness, one that's difficult to work around. The Apply Image technique described previously will help to minimize their visibility. Unsharp masking the Luminance in Lab doesn't help, because unlike typical digital camera noise which is confined to the chrominance (colour) of an image, digital dust is found predominately in the Luminance. This effect can be seen faintly in "Blue channel after Quantum Mechanic" above, and in the before frame available for download in the Apply Image section.

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Fortunately, fireworks photos can sneak through pre-press with lower than normal newsprint unsharp masking values and still look sharp in print. Don't rule out tricks like selectively sharpening fill-flashed humans in the foreground, for example, while leaving the light bursts untouched. Also, use the Curves tool to darken up the areas of the sky where the digital dust, and blue channel noise, predominates. Then, count on dot gain and other ink-on-paper evils to smooth any remaining unwanted guck into oblivion. If the image is to run small, the process of resampling the image downwards will also eliminate a lot of visible noise.
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Limiting noise and applying careful sharpening, in conjunction with the usual pre-press regimen at your paper, should result in great-looking images print.

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