• Nikon SB-910
• Nikon SB-900
• Nikon SB-700
• Nikon SB-300
• Nikon SB-800
• Nikon SB-600
• Nikon SB-400
Nikon CLS Commander:
• Nikon SU-800
• Nikon PDF on their Creative Lighting System:
In a nutshell, I’ll typically make an i-TTL test exposure with a subject, evaluate it on the LCD, and, if necessary, make on-the-fly adjustments using the flash compensation dial on my camera (this mostly applies to event coverage–for studio applications, everything is set to manual).
However, if you also want to expose for the background, that requires a slightly different technique. While my flash is still set to i-TTL mode, I’ll typically set the camera in manual mode: First, I’ll dial in my preferred shutter speed (the minimum required to freeze most motion, but not more than my flash’s sync speed–typically 1/250th). Second, I’ll select my preferred aperture (if shooting singles or small groups, generally around f/5.6). Lastly, I’ll dial-up my ISO until I can expose for the ambient (background) light level (my flash then automatically adjusts its i-TTL output accordingly). Since I’m shooting with full-frame bodies, I have quite a bit of headroom with my ISO setting before the noise level becomes unacceptable. If I find that I still need more exposure for the ambient, I’ll drop my shutter speed slightly (e.g., 1/160th), and/or open up my aperture slightly. If it’s really dark, I’ll switch to a faster prime, open up, and focus as precisely as possible, often hovering an active focus point over the subject’s eye.
1.) Exposure settings: Generally speaking, for flash-fired interiors, I’ll typically shoot at low- to moderate-ISOs. But, if I need to reduce my recycle time, I may increase my ISO to 400-800. If, however, I’m also trying to expose for the ambient light level (i.e., by “dragging the shutter”), I may increase my ISO significantly (while, at the same time, lowering my flash output). I typically shoot in manual mode. My exposure is usually set at 1/250th, between f/4.0-f/5.6 (shooting at f/5.6 usually lends enough depth-of-field to get both subject’s eyes in focus in a two-shot). Since shutter speed and aperture are set manually (i.e, “fixed”), the only variables which remain are ISO and flash output power (which can either be set manually, or set to i-TTL).
2.) Manual flash: I’ll choose manual flash only if I know subject distances will remain relatively constant (for studio set-ups, everything is always on manual). The benefit to manual flash is that it won’t change–no matter what the reflectance is in the scene you’re shooting–that is, if this exposure is “correct,” it stays “correct.” First, I’ll estimate a power output, select a shutter speed and aperture (e.g., 1/250th @ f/5.6), and shoot a test exposure with a subject at a specific distance. I’ll simply “chimp” the LCD to adjust my flash output power to taste. Assuming direct-flash, this power level should work for most subjects at that same distance.
3.) Auto i-TTL flash: Nikon’s i-TTL system is uber-convenient, and usually spot-on (though, sometimes, it’s not). But, even if things are bit under- or over-exposed, I’ll simply dial my flash-exposure compensation button on my camera up or down +/- 0.3-0.7 EV. I find this method a very fast and efficient way of using i-TTL. Again, setting exposure manually leaves your system’s i-TTL to do all the hard work. The only two variables which remain is your flash-exposure compensation setting, and your ISO. My favorite i-TTL technique is to hold a 5″ x 7″ PortaBrace white balance card in my left hand, bouncing my on-camera flash into it, by turning the flash head to the left, and slightly rearward. This technique works great, and as I mentioned, my Nikon i-TTL is generally spot-on.
I have to append my point about using manual flash–I forgot to add the caveat that this approach only applies if you’re using a constant-aperture zoom lens. If using a variable-aperture zoom lens, the amount of light reaching the sensor varies with focal length, so you now have two variables to contend with, in addition to subject-to-camera distance: flash output power, and focal length. In this case, I would recommend only using your flash in E-TTL mode (Canon), or i-TTL mode (Nikon), and let the flash calculate its output for you. Again, you can still adjust what the flash thinks is “correct” exposure by using the flash-compensation dial on your camera