Nikon D80 Exposure Options
The Nikon D80 gives you all the exposure options you'd expect in a high-end prosumer SLR, plus a few surprises. Available exposure modes include Program AE, Manual, Aperture Priority, and Shutter Priority modes with shutter speeds from 1/4,000 to 30 seconds available, as well as a Bulb setting for longer exposures. While an impressive range, the 1/4,000 top speed is a full stop down from that of the D70/D70S, a reduction in shutter speed that also shows up in the D80's lower 1/200 second x-sync speed, a significant drop from the 1/500 second x-sync of the D70/D70S. (See the discussion below about "Shutter Control vs CCD Gating" that explains the benefit of the D80's approach to exposure-time control.)
A very nice touch that's common to other Nikon DSLRs is that, while in Program AE mode, you can rotate the Main Command dial to select different combinations of aperture and shutter speed settings than those normally chosen by the autoexposure system. (That is, if the automatic program would have chosen 1/125 second and f/5.6, you could instead direct the camera to use 1/60 at f/8 or 1/30 at f/11, to get greater depth of field.) This is a very handy option for those times when you need some measure of increased control, but still want the camera to do most of the work for you. We personally use this capability more than Aperture- or Shutter-priority metering in our own shooting.
An interesting feature when using Manual exposure mode is the electronic analog exposure display visible in the optical viewfinder data readout. This shows the amount the camera thinks an image will be over- or underexposed, based on the settings you have selected, and helps you find the best exposure for the subject.
ISO sensitivity ranges from 100 to 1,600, adjustable by pressing the ISO button and turning the Main Command dial to change the setting. Scrolling past the 1,600 setting offers HI-0.3, HI-0.7, and HI-1 settings, which translate to High ISO +0.3, +0.7, and +1.0 EV settings above the 1600 mark. (The maximum ISO setting is thus 3200.) ISO values are adjustable in 1/3 EV increments across the full range, but there's no option for 1/2 EV adjustments as in the D200. (Not a significant loss of capability, in our opinion.) A High ISO Noise Reduction mode in the settings menu lets you increase or decrease the effect of noise reduction processing when shooting at the higher sensitivity settings (800 and above), in addition to the standard Noise Reduction option for longer exposures (which itself can be turned on or off as desired).
White Balance Options
White balance modes on the Nikon D80 include Auto (usable from 3,500K to 8,000K), Incandescent (set to about 3,000K), Fluorescent (4,200K), Direct Sunlight (5,200K), Flash (5,400K), Cloudy (6,000K), Shade (8,000K), Choose K Temp (adjustable from 2,500 to 10,000K), and Preset (which allows you to manually adjust the white value by using a white card or object as a reference point). All white balance settings are adjustable from -3 to +3 units on an arbitrary scale by turning the Sub-Command dial (on the front of the hand grip) while pressing the White Balance button (with the exception of the Preset option, which is not adjustable). While we called it arbitrary, in all but Fluorescent white balance mode, each step on the fine-tuning scale corresponds to 10 mired of color shift. The fluorescent setting provides a wider range of variation to accommodate the wide range of colors available in fluorescent lighting. You can also bracket white balance exposures (see the Autobracketing discussion below). Higher values correspond to a decrease in the camera's white point, in degrees Kelvin (meaning the images become "cooler" in appearance). This is a very nice feature, as we often wish we could use one of a camera's standard white-balance settings, but tweak it to be just a bit warmer or cooler than the default. To be sure, some experimentation would be required to familiarize yourself with the impact of these "tweaked" white balance settings, but having them available is a big plus. The table below shows approximate white point temperatures in degrees Kelvin for the various adjustments in each of the major white balance settings.
We confess that we were surprised to see that Nikon had dropped the maximum x-sync shutter speed and maximum absolute shutter speed on the D80 relative to the capabilities of the earlier D70 and D70S. While the slower shutter speeds do limit the camera's capabilities somewhat (that 1/500 x-sync speed was great for taking "flash only" shots under bright lighting), it turns out that the change has brought about a very significant improvement in another area, namely exposure "blooming" on the CCD caused by strong light overloads. The shots below show the difference between the D70 and D80 in two identically-exposed images, with the sun intruding on the image area.
|D-80 vs D70 CCD Blooming
(Click on any image to see full-size version)
Both shots above were captured with the same ISO, shutter speed and aperture settings, but the shot from the D70 shows horrible streaking around the overexposed sun. (This is generally a bad idea, by the way, direct images of the sun on your CCD can cause damage if you're not very careful. - So don't try this at home.)
What's going on with the D70's sensor here is called "blooming": Extreme overexposure can cause charge to bleed from photo-active areas into adjacent ones, or into shift register cells used to transfer the charge off the chip so it can be measured.
It turns out that the D70's shutter only governs relatively long exposures: Shorter exposures are controlled by "gating" the sensor chip, starting and stopping its light-gathering electronically. This lets you achieve very fast shutter speeds economically, but has the limitation that the sensor's surface is actually exposed to incoming light for a period of time much longer than the exposure itself. Normally, this causes no problems, but as we see above, massive light overloads can bleed charge into the CCD's transfer registers while the image data is being read out. The result is horrible streaking.
In the shots above, the sun itself was directly in the field of view, so it's very much a worst-case example. The same thing can happen with much smaller areas of strong highlight, as would be found with the sun glinting off chrome or some other reflective surface. Very annoying, to say the least.
So why doesn't the D80 show the same behavior? Because Nikon gave it a "real" shutter, capable of exposures down to 1/4,000 second on its own. Really high-speed shutters are more expensive to build than merely fast ones, so Nikon chose to give the D80 a fast focal-plane shutter, but drop its maximum shutter speed to 1/4,000 in the process. (This is another area where the D200 surpasses the D80; it has a shutter capable of delivering 1/8,000 second exposures directly.)
This strikes us as a pretty important feature of the D80, but to the best of our knowledge, it hasn't been reported on by any other review organizations.
Nikon D80 Metering Options
The D80 has three metering options: 3D Color Matrix II, Center-Weighted, and Spot. The 3D Color Matrix II setting integrates exposure information from a large number of areas across the frame (useful when brightly colored or very dark subjects occupy a significant portion of the frame) with distance information from the microchip in D- and G-series lenses. The result is much more accurate metering response than more conventional center-weighted metering would provide. The D80 uses a 420-segment RGB metering sensor for its 3D Color Matrix II metering, vs the 1,005-segment one in the D200 and D2Xs, but does still use the same 30,000-image database for judging exposure. Center-Weighted metering measures light from the entire frame but places the greatest emphasis on a circular area in the center, marked by the large circle in the viewfinder. (The size of the Center-weighted metering area can be changed via Custom Settings Menu option 12 to either 6 or 10mm from its default value of 8mm.) Spot metering takes a reading from a 3.5mm circle centered on the active focus area only, covering about 2.5% of the frame.
The D80's Exposure Compensation adjustment increases or reduces the overall exposure from -5 to +5 exposure equivalents (EV) in one-half or one-third step increments, in all exposure modes. An Auto Bracketing feature captures multiple shots with different exposure or white balance values determined by either the photographer in Manual mode or by the camera in all other modes. (See below for details.)
A new addition is the Exposure Delay mode, which delays the exposure for a few tenths of a second after the mirror raises, to let the the mirror shock subside (intended for times when the camera is on a tripod). This is intended to have the same effect as the Mirror Up shooting mode on other Nikon SLRs, but differs in that Mirror Up mode requires two actuations of the shutter button (or remote) to fire the shutter, whereas the Exposure Delay of the D80 handles the delayed shutter release automatically.
When reviewing images on the LCD monitor, you can call up a histogram and a highlight function to give you a complete readout on the exposure. This is a useful tool to examine your exposure in the camera instead of waiting to download images and then deciding to reshoot. One change from the D200 though is that the D80 can't blink highlights independently for the R, G, and B color channels, but rather bases its highlight blinking on the luminance value alone.
Nikon D80 Continuous Shooting Modes
The Nikon D80 offers a single continuous shooting mode, accessed via the Drive Mode button on top of the camera. Only a single drive mode is offered (vs the separate low and high-speed modes on the D200), with a frame rate of three frames/second. This matches the performance of the original D70/D70S, fairly impressive considering how much more image data the D80's processor has to contend with. The D80 also sports the obligatory self-timer mode, with delay options of 2, 5, 10, and 20 seconds.
Nikon D80 Exposure and White Balance Bracketing
Most digital cameras these days offer some sort of exposure bracketing, but the bracketing function on the Nikon D80 goes beyond simple exposure adjustment, to permit white balance bracketing as well. Bracketing settings are controlled via Custom Settings Menu option 13, where you can choose to bracket both normal exposure and flash, normal exposure only, flash only, or white balance.
Bracketing is controlled by holding down the BKT button and rotating the Command Dials. The Main Command dial selects either 3 or 5 frames per bracket, while the sub-command dial selects 0.3, 0.7, or 1.0 EV step sizes for exposure adjustment. Auto exposure bracketing can thus cover as wide a range as +/- 2.0 EV, in steps of 1 EV, or +/- 2/3 EV in steps of 1/3 EV.
White balance bracketing can occur in the same 3 or 5-shot brackets, with the step size between shots being either 1, 2, or 3 of the white balance "fine tuning" steps. (As noted above, each such step corresponds to 10 mireds of color-temperature adjustment except when in Fluorescent mode, which offers larger steps.) Normal white balance bracketing can thus cover a range from +/- 10 mireds (3 shots, 1 step each ) to +/- 60 mireds (5 shots, 3 steps of variation each).
Nikon D80 "Image Optimization" Options
The Nikon D80 also offers the by-now-familiar Optimize Image option, accessed through the Shooting menu, which lets you adjust sharpness, contrast, saturation, and hue. A Custom setting accepts downloaded tone curves created in Nikon's Capture application (version 4 or later) and then downloaded from a computer. (If no curve is downloaded, the Custom setting defaults to the Normal setting.)
You can also opt for a black-and-white shooting mode, which on the D80 offers a nice enhancement, in the form of "color filtration" mimicking the effect of color contrast filters when shooting with black-and-white film, to enhance clouds, etc. Color contrast filter options in the D80's black and white mode include yellow, orange, red, and green. You can also set the contrast and sharpening for black and white shooting entirely separately from the controls for full-color mode, so you could dial-in a special tone curve for your black and white photos without disturbing the camera's normal color characteristics. Overall, the D80's black and white mode goes far beyond what we're accustomed to seeing, and its color contrast filtration is the equivalent of carrying a bagful of color filters back in the film days. (No worries anymore about having the wrong size color filter for the lens you were shooting with!) It's also important to realize that if you shoot in NEF+JPEG mode, you can play to your heart's content with color contrast filtration, while still preserving the original (full-color) RAW-format NEF file on the memory card. This gives you great freedom to experiment in the field, knowing that all the original image data remains untouched in the NEF "negative." Pretty slick!