Sunday, December 21, 2014

200 Shots In One Hour

Photo #1
It's not what it sounds like. Thanksgiving at the Adult School is a festive event, a school-wide pot luck with food from around the world. Cuisines from every continent except Antarctica are represented. While for many it's a first encounter with a  roast turkey, it is still a bonding experience, a community builder in a classroom.

The idea behind today's shoot was to see how many images I could make in one hour. I was aiming for 200, which would mean that I was making a photo every 18 seconds. Once I accepted my own challenge, I had to decide what equipment to use.

Photo #2
The Camera: I needed a reliable setup that would be easy to use and would provide consistent results. Let's talk about he equipment first. The camera was a Nikon D40, (Photo #2), an entry-level DSLR introduced in 2006. To cut costs, Nikon removed in internal focusing motor and instead relied on the AF-S lens line which employed a focusing motor built into the lens itself. Second, the operations were heavily menu driven, eliminating the need for external button controls. Third, the Control Panel on the top plate of the camera body was eliminated, forcing the LCD panel on the back to perform playback and menu display functions. The mostly plastic 18-55 3.5 - 5.6 AF-S lens, the standard kit lens for entry level Nikons, is probably the least expensive zoom lens in the Nikon catalog. 

I chose this camera as an example of the sort of camera frequently found in the hands of the volunteer event photographers I often meet. The D40 and the subsequent iterations ( The D3xxx and D5xxx series) are similar in operation but offer more pixels, a real improvement. The basic kit lens is pretty much remains the same, and is perfectly adequate for this kind of shooting. 

The Flash: From here out, my selection of the bits becomes more diverse. The flash is a Vivitar 283 modified to use a flash tube that is parallel, not perpendicular to, the lens axis. When used with a parabolic reflector,  hot spots on the subject's face are reduced. My particular unit has a 1/4 CTO filter to improve flesh tones. The 283 is not a TTL flash, but instead utilizes a built-in forward-facing sensor to dollop out the proper exposure when used with a specific ISO/aperture combination. Because of the high triggering voltage typical of Vivitar flashes, a Wein Safe Sync was installed between the hot shoe and the flash to protect the camera from being "fried". A PC/Household cable was used to connect the two because the Vivitar has a Holly aluminum replacement foot. Because the Safe Sync does not have the Speedlight Present contact, the outfit could synchronize the flash at almost any speed. Nearly any flash can be used for this type of work, as long as the trigger voltage is low enough. My use of the bare tube modified Vivitar was a matter of convenience.

The Bracket: The final key component of this system is the flash bracket (QRS-35, now discontinued)  made by Custom Brackets. You can see that it raises the flash well above the lens axis, giving more pronounced shadows and softer highlights. If I was only making a few images, I wouldn't bother with the bracket and would simply hold the flash aloft with my free hand. But with my goal of 200 shots in one hour, working without a bracket would quickly get pretty tiring. Flash brackets have fallen from vogue in recent years, and can be found at camera shows at very reasonable prices. The best ones center the flash directly over the lens, and some allow the camera to rotate while maintaining the flash's location high over the camera.

The QB (Custom Brackets) are expensive, but they make a quality product. The are manufactured from machined aluminum with brass screws when needed, and are rugged. You can find brackets that are much cheaper, but the quality isn't any where near that of the QB. Stroboframe brackets are excellent, too.

Photo #3
 The D40 shares the "sync at any speed" quality with the Nikon D70s and the D50.  This allows me to sync at almost any speed, making it well adapted to shooting indoors and out. In Photo #3, the camera was set to 1/500, F 5.6, ISO 200. With my subject in the shadow of the buildings behind me, the flash was the sole source of subject illumination, so the existing light on my subject's face could be ignored.

Photo #4
Unfortunately for me, the freedom from thinking about synchronization speed lead to inattentiveness on my part. In Photo #4 I forgot to set the shutter speed my shorter "outdoor" setting after stepping out from an indoor venue. As you can see here, the background was a bit "hot". The exposure setting for this shot was 1/200 of a second with the aperture remaining at 5.6 and the ISO still at 200. Luckily, the subject is still well exposed, and the bright overexposed background could be ignored for this shot.

Photo #5
Backgrounds: Here's a quick rule when working under these "run and gun" situations: Keep your subjects as close the the background as you can. This will keep the exposure levels reasonable close to those on your subject. In Photo #5, the subjects are just a few feet from the background wall, and while not ideal, the results are acceptable. Watch out for a background that is angled from the lens axis. You'll see how the light falls off from camera right to camera left in this shot.

Photo #6
In Photo #6, you can see that the background is some distance away, and is much darker than Photo #6. Keep in mind that when working in a room as it was in these shots, you can't always move the subject closer to the background. Here, my sitting subject was close to the middle of the room. The exposure for these two shots was 1/125. No attempt was made to take the ambient light into account, mainly to prevent color contamination from the existing fluorescent. Sure, one could have filtered the flash to match the existing light but then I'd have to try to balance the two sources (ambient and flash) which would consume valuable time.

Photo #7
Glare: Glare from the background is almost inevitable. In this shot, you can see a sort of "glow" on the whiteboard background. If the camera is perpendicular to the background and the camera held perfectly level, the "hot spot" will appear in the exact center of the image. Any deviation from the perpendicular will alter the location of the hot spot. As a general rule of thumb, keep your subject centered in your viewfinder and your lens axis as close to perpendicular as possible.
Photo #8

You can see in Photo #7 that the hot spot is mostly covered by the subjects. The slight downward angle of the shot moved the glare spot 

In Photo #8, it is complete concealed by the subjects and the (slightly) high camera angle. 

In the end, I made nearly 200 photos, but by the time I culled out the clunkers, I wound up with 80 usable images, and I did it in one hour. And using direct flash allowed for fast recycle times and relatively long battery life. Truly, an easy shooting day!