eStore 
   

Notice: This page may contain advertisements. Click on the disclaimer for details.

Flash Units

In this section, I will review the photo equipment I typically take on board cruises, how I pack the equipment, and some photo examples. I rarely take all of the equipment on a given cruise, but rather tailor what equipment I take to where we are going.

The three rules of taking a good photograph are composition, lighting, and opportunity. Composition is a learned skill, in that you get better with time. Lighting however is almost always improved with use of a flash. Your camera probably has a built-in flash, so why do you need a dedicated flash unit? The simple reason is that dedicated flash units are generally more powerful than a built-in flash. And some lenses interfere with the built-in flash.

Almost all portrait photography looks better with an off-axis and diffused flash units. Even for daylight use, a flash unit often aids in lighting, especially for photos that are back-lit. While you should always refrain from taking photos into the sun, it is not always avoidable. So even in a cruise environment, carrying a flash unit is not a difficult undertaking.

Nikon SB700 Overview

Nikon SB-700 Speedlight

Specifications
Metering: iTTL/manual
Wireless Flash: Yes (with Nikon CLS)
Lens Coverage: FX/DX zoom
Power Source: AA Battery x 4
Manufactured: China
Street Price: $320


Alternatives

Overview: Using a flash off-axis requires some method of triggering the flash when the camera shutter is depressed. Traditionally, this was done with a flash cable between the flash unit and camera. Fortunately with the modern flash units available, this is done wirelessly. With Nikon at least, this requires a minimum level of equipment. Nikon calls this capability as their Creative Lighting System (CLS). Only flashes as the SB-600, SB-700, and SB-900 have wireless capability (the SB-400 lacks this), As well, the camera itself needs to have wireless capability. Cameras that have this capability are generally the Nikon D90 and above (The D3000, D3100, and D5000 lack this feature).

An option is to mount a SB-700 or above on the camera's hot shoe and use a second SB-600 + as the off-axis flash. The SB-700 can drive a slave flash. However, this gets expensive fast as it requires purchasing at least two flash units - not to mention you are lugging more equipment. Far better to buy a Nikon D90 instead.

Caution:

When using flashes not recommended by the manufacturer, you risk damage to the camera. Some flashes, particularly older ones, can present a high voltage to the camera's flash trigger that may damage a modern DSLR. While there are products on the market that can isolate these high voltages, the reader is cautioned against using anything not recommended by the camera manufacturer.

Off-Axis flash: Or off-camera flash, if you prefer, often results in more pleasing photos, especially with portraiture. Shown below is a SB-600 flash, coupled wirelessly to the camera, and the camera's flash used as a second flash. The SB-600 can be placed on a tripod, held by an assistant, or held by the photographer at arm's length (if the assistant is the subject of the photo). I took a series of 4 photos as shown below, demonstrating the capability of the Nikon CLS system, which allowed me to vary the light balance between the on-camera and off-axis flash. Notice the left side of the box is consistantly the same light level as the front light level is varied from -3EV to 0EV. This was done simply by selecting a flash value from the camera's CLS menu for each photo.


Left Flash EV=-0, Front EV=-3

Left Flash EV=-0, Front EV=-2

Left Flash EV=-0, Front EV=-1

Left Flash EV=0, Front EV=0

Daylight Fill Flash: Whether its a bright sunny day or overcast, the sun can play havoc with exposure levels if it is behind the subject. In the left photo below, the background was properly exposed, but the foreground was underexposed. Adding fill-flash corrects this problem. In this case, fill-flash is done at the camera axis, so the flash can be either the camera's built-in flash or a dedicated flash mounted on the camera's hot shoe.


Little Stirrup Cay (Coco Cay), Bahamas.

Fill Flash - Little Stirrup Cay (Coco Cay), Bahamas.

Flash Power: Flash power is typically measured by a unit called Guide or Guide Number. It is essentially the distance in ft. a flash can properly exposure an object at a given ISO speed (however sometimes it is measured in meters). A flash with a Guide of 130/ISO 100 means at ISO 100, it can properly illuminate an object up to 130ft from the camera. Obvously, the larger the Guide number, the more powerful the flash.

Most flashes today have some sort of automatic exposure control so that should the object be closer (and not requiring the full power of the flash), it will "throttle-back" and send only the amount of light needed. Most flashes also have a manual mode, where the flash can be made to supply full power, which requires proper exposure control in the camera. This of course, eats batteries. Since there are so many variations, consult your flash and camera instruction manual for proper settings.

Advanced Settings: Settings such as front curtain sync, rear curtain sync, red-eye reduction, fast shutter, slow shutter, and similar are so widely varied between the manufacturer and models that a chapter could be written on this topic alone. Suffice it then to review your manual for your specific camera and flash if you desire to use these features.

Summary: Now that you have a better idea of how you can use a flash to create better photos, you will wonder how you got along with out it. But we're not done yet. Another concept in flash creativity is to bounce the flash, or use diffusers. Direct light from a flash can be harsh, and in some cases, reflect off hard surfaces, causing a objectionable reflection in the photo. This is often solved by bouncing or use of a diffuser. The relatively small area of the flash is increased in size, which tends to soften the flash, and a softer flash doesn't tend to reflect as much.

Bouncing is a technique whereby the flash head is pointed up to the ceiling or onto a wall. The flash reflects back down to the subject. Of course, a white ceiling or wall works best, as color walls can reduce the amount of light reaching the subject, as well as the reflected light will pickup the color of the wall. The light intensity isn't usually an issue as the flash is smart enough to meter the proper amount of light, but the color change is sometimes hard to correct. You can try to change the white balance or make the changes in post-processing. A third problem with bouncing is shadows. Especially when taking portraiture, shadows under the eyes, nose, and chin will occur as the result of the light coming from overhead.

For these reasons, a diffuser is often used rather than a bounce. Diffusers are commercially available, or you can use something as simple as shooting the flash through a 8x10 piece of paper, bed sheet, or other semi-translucent material. The diffuser is placed in front of the flash and tends to scatter the light, thereby diffusing it.


Gary Fong LightSphere

Opteka Mini Soft Box

Opteka Flash Diffuser

Gary Fong Puffer

Of the available diffusers, I like the fabulous Gary Fong Lightsphere. The collapsable version is great for travel as you don't have to figure out how to store it. I also like the soft-box type. It is the largest - providing more diffused area, and it folds flat. It is made of flexible vinyl so there is almost no weight to it at all.