Managing photographic exposures using ambient light involves managing a triad of sensitivity, shutter speed, and aperture. Change the value of one element of the triad, and like the sides of a triangle, at least one of the other elements must also change, or the exposure becomes incorrect.
In the days of film, sensitivity was conceptually fixed at a particular ISO. Thereafter, only two sides of the triangle could be adjusted. Automation allowed one to adjust those two sides by moving their vertex. The only choice (on a full-featured camera like the F5) was from which direction to approach the vertex: aperture-priority or shutter-priority. In practice, this was trivial. I always chose aperture-priority because it's all my FE2s had.
In the world of digital photography, one can adjust sensitivity from frame to frame. This is a great power with which comes additional conceptual responsibility. One must develop new patterns for managing the triad.
I'm currently evaluating two different patterns of exposure management on the D3: "P" and "M". I'm not exploring any options that require manual ISO adjustments, because the D3's controls do not make it easy to identify the ISO button by touch alone -- especially when wearing gloves. Whether I settle on just one pattern, or switch between the two depending on the situation, remains to be seen.
Pattern "P" is encouraged by the D3's default settings. The disadvantage is that shutter speeds that would match (for handheld use) a zoom lens's shorter focal lengths will be less accessible:
- P: Programmed Automatic mode. I used to get hung up on a desire to return the camera to its standard program after using a command dial to deviate from it, but I finally realized that this was pointless. All I was deviating from was the median compromise. Big deal.
- On every lens change, set the Auto-ISO Minimum Shutter Speed to match the lens's maximum focal length. This is less of a hassle now that the firmware provides a better way to access frequently-changed menu options.
- Adjust the aperture-shutter vertex via one command dial.
- Auto-ISO ON with Maximum sensitivity = Hi-2. This provides maximum ISO flexibility.
- M: Manual mode. This is the only mode in which the camera will loosen its death grip on ISO 200. In all other modes, the camera would rather reduce shutter speed to below hand-held range than increase ISO (and therefore noise). I'm willing to accept the noise if it's the difference between getting a sharp shot or a blurry one.
- Adjust aperture and shutter speed via two command dials.