Metering (Advantage: Nikon D200)
The Canon EOS 5D and the Nikon D200 each have implementations of the three common metering patterns: Spot, Averaging and Evaluative. The implementations vary. While they do well in typical lighting, unsurprisingly we found that neither evaluative nor matrix will fully protect the user from making mistakes in difficult situations.
The 5D's spot meter is a relatively large area, indicated by a circle at the center of the viewfinder. Canon says it covers about 3.5 percent of the frame. That seems small until one considers that it would cover any two contiguous autofocus sensor sites. The D200's spot sites are about 2 percent of the frame, so it is a bit more precise than the 5D in that respect. However, the D200 can also be set so that the meter measures the 2 percent spot centered over the active autofocus area. The 5D lacks that feature – its spot meter is linked to the autofocus sensor at the center of the frame. This is a more substantial difference; the D200 will enable the user to meter off-center subjects without adjusting the composition, while the 5D requires the user to move the center of the frame over the subject, meter and then recompose.
The 5D adds a much larger circle. Its “Partial” pattern is an 8 percent spot at the center of the frame, which is so large that it's a bit like a tight averaging pattern. The averaging patterns on the two cameras vary, though both take a single reading with sensitivity concentrated at the middle of the frame. The D200 allows the user to select the size of the center area that is emphasized, from 6 to 13 mm. This again provides an additional layer of control that is not present on the EOS 5D.
The evaluative or matrix settings on the two cameras are designed to take many separate light readings across the frame and evaluate them. Ideally the cameras should be able to detect backlighting and other situations that can throw off averaging modes and set an exposure that delivers good detail and color on the main subject.
We shot two scenes that seemed sure to fool averaging modes and likely to challenge evaluative modes: we shot a bag of potato chips backlit on a window ledge, and we shot the same bag and a couple other bright items on a black felt background. We left the center of the black background empty, to see if the evaluative modes could find the subjects.
EOS 5D - Center-weighted Average
D200 - Center-weighted
The evaluative modes on both cameras performed better than straight averaging, but that was easy to determine – both averaging modes did a lousy job. The evaluative modes set “compromise” exposures. With both cameras, our bag of chips is dark in the backlit photos and light in the shot with a dark background, while the backgrounds in each case retained some detail. All that stands to reason – any automated exposure system should be tuned to maintain detail across the image, when it can. When we pointed the spot meters on the subjects in each scene, we got good exposures of the subjects and lost the backgrounds. Here, we found the D200’s movable spot meter a big advantage.
EOS 5D - Evaluative
D200 - Matrix
In all, metering performance was comparable in most modes, yielding similar exposures from both cameras when put in the same shooting situation. However, differentiation emerged in the degree of control available on the two cameras. The D200 offers far more flexibility and customization – something you’d expect in the more expensive EOS 5D. Furthermore, the additional control granted by the D200’s customizable center-weighed region and movable spot points is not just padding for the spec sheets. These options provide more practical solutions to challenging lighting, increasing efficiency and enabling the photographer to tailor the camera to their workflow.
Exposure (Advantage: Nikon D200)
In shooting comparison images, we noticed that the best shots from the 5D and the D200 were usually not at the same exposure. The 5D produced lighter images at a given ISO and exposure, indicating the increased light sensitivity of the 5D’s full-frame CMOS sensor. The D200 needed 1/3 – 2/3 of a stop more exposure than the 5D. Adding an additional check, we shot both cameras on manual and took an incident reading with a Konica Minolta Autometer VF to determine exposure. The D200 agreed with the handheld meter but delivered a dark exposure, while the 5D took a good exposure but indicated that it wanted another 1/3 stop.
EOS 5D - ISO 100, 1/15 sec, f/7.1
D200 - ISO 100, 1/15 sec, f/7.1
The cameras differ more substantially in the degree of compensation they allow for a given exposure. The 5D remains true to the prosumer or consumer-level DSLR standard, offering exposure compensation 2 stops above or below the metered value, while the D200 extends the range to a 5-stop bias. The D200 also shifts flash exposure compensation, weighting the bias for fill flash with a -3 to +1 EV range, while the 5D’s in-camera flash EV compensation remains +/- 2.
In addition to offering a more expansive range, the D200 allows the user to set an AEB sequence of up to 9 images in 1/3-, 1/2-, or full-stop increments, while the 5D only offers a 3 shot sequence in 1/3- or 1/2-stops. The D200 also provides a dedicated BKT button on the back of the camera for quicker access to the function, a control that would have been nice to see on the 5D. However, the 5D can link the entire (3 shot) bracketed sequence to the self-timer, a feature ideal for architectural work that is unfortunately absent from the Nikon. This allows users to press the shutter release a single time and capture three bracketed shots of the composition. Users of the D200 will either have to hold the shutter down for the duration of the burst or depress the release for each shot.
Autofocus (Advantage: Nikon D200)
Both the D200 and the 5D improve on the autofocus performance of their manufacturers' entry level cameras, but fall well short of the top of the line. The Canon EOS 1D series, for instance, has 45 autofocus sensors, while the 5D has 9, plus 6 invisible supplemental points. The 5D also has three autofocus sites where vertical and horizontal sensors overlap. The D200 has 11 points, which can be combined to form 7 wide-area points. The D2X and D2Hs from Nikon have 9 cross-type sensors, while the D200 has only one.
Our experience examining the 5D and the D200’s focusing abilities generally indicated that the cameras perform comparably in most ways, particularly in tracking moving objects, although the D200's autofocus focused a bit better in low light.
To test tracking, we put 50mm f/1.4 lenses on both cameras, and took bursts of cars as they passed through an intersection near DigitalCameraInfo.com's world headquarters in Somerville, Massachusetts. We trained the active AF sensor on the front left wheel of the cars we photographed. We shot some in aperture priority, with the aperture set to f/1.4, and some in shutter priority, with the shutter set to 1/8000. We set the cameras to ISO 100. Our object was to keep depth-of-field at a minimum. In this evaluation, we found that the cameras performed similarly, both producing sharp images most of the time with neither presenting a clear advantage over the other.
We checked low light performance in a darkened room, shooting objects with varying contrast and texture with zoom lenses. Light levels called for exposures of between 1/4 and 2 seconds at f/4.0 for ISO 400. We found that the D200 could focus on wood-grained melamine in the darkest conditions. The 5D hunted and did not snap into focus when we shot horizontally. When we turned the camera vertical, the 5D could focus. Canon reports that the horizontal sensors at the middle of the 5D's frame are active at apertures of f/2.8 or faster. Since the 24 to 105mm lens we were using only opens to f/4.0, those sensors didn't operate, and turning the camera oriented the more light-sensitive sensors appropriately for the texture we were shooting.
The most obvious distinction between the 5D and D200's focusing systems is that the D200 has an AF assist light. We didn't use it in the comparison, but it is bright and effective. In circumstances where it's appropriate to use AF assist, the light provides a huge advantage. Both Canon and Nikon dedicated flashes also provide AF assist lights.
