Nikon D90 Exposure
Nikon D90 Exposure/Capture Enhancements
The Nikon D90 offers a number of advancements over its predecessor the D80. We'll mention them here, and then discuss some of them in more detail below.
The Nikon D90's 12.3 megapixel sensor isn't exactly a quantum leap beyond the D80's 10.1-megapixel chip, but a little extra resolution is always welcome. - As long as it doesn't bring higher image noise along with it. Nikon claims new, more advanced noise reduction processing on the D90; if so, the extra two megapixels of resolution will be a nice addition. Indicative of Nikon's confidence in their new noise-reduction algorithms is the D90's higher ISO range of 200-6,400. (The D80 ranged from ISO 100 to 3,200.) Like the D80 though, the D90's sensor and A/D system delivers 12 bits of raw image data, vs the 14 bits of the D300 and other higher-end Nikon DSLRs.
High-endurance shutter mechanism
Like most consumer-level DSLRs, the D80's shutter carried no rating for total lifetime cycles. For the D90 though, Nikon is rating its shutter at 100,000 cycles. This isn't quite to the 150,000 to 300,000 cycle ratings of some pro-grade SLRs, but it's a pretty substantial number nonetheless. An explicit shutter lifetime rating is a first for Nikon in a consumer or prosumer-level SLR, and speaks well for the D90's long-term durability.
New, highly advanced exposure system
When they were announced in late August, 2007 (almost exactly a year ahead of the D90), the D3 and D300 marked a significant advance in exposure metering technology. Nikon's 3D Matrix Metering had long been an industry standard for exposure accuracy when faced with tough subjects and difficult lighting conditions, but the D3/D300's system took Matrix Metering to a new level. Changes in the optical path for their 1,005 element RGB exposure/white balance sensor greatly improved scene-recognition accuracy. This technology has now been brought forward to the Nikon D90. Although its RGB exposure/white balance sensor has fewer elements (420 vs 1,005), this improved scene-recognition technology promises improved exposure accuracy for the D90, beyond the already-excellent performance of the D80.
D-Lighting is Nikon's name for their technology that balances exposure in highlights and shadows. On the D80 D-Lighting was a Retouch menu option, where it could be applied to images after they were captured. On the D3 and D300, the new D700, and now on the Nikon D90, D-Lighting is still an option on the Retouch menu, but can also be found on the Shooting menu as Active D-Lighting. Active D-Lighting does the same things D-Lighting has always done (typically, holding back highlights slightly, while boosting shadow brightness), but now does it on the fly, at the moment of capture. On the D90, though, Active D-Lighting's capabilities are expanded beyond those of the previous pro cameras through the addition of the Extra High option. (The pro cameras' Active D-Lighting options include Off, Low, Normal, High, and Auto.) Nikon told us that the advanced scene recognition used in the exposure system also informs the Active D-Lighting system, particularly in photos containing people's faces.
We didn't get a chance to play with Active D-Lighting on the Nikon D90, but have been quite impressed by it on the D3, D300, and D700. We're generally not fans of cameras' monkeying with contrast and tonality on their own, but have to admit that Nikon's Active D-Lighting gets it right more often than not (to our eyes, at least). We also like that it leaves the NEF RAW files completely alone (its effects are only applied to in-camera JPEGs), so we always have an undisturbed original to tweak manually if we don't like what D-Lighting did with a subject.
|Nikon D90 Active D-Lighting Options|
|Active D-Lighting appears on the Nikon D90 for the first time in a consumer DSLR.||As with several other features, Active D-Lighting on the D90 has been enhanced even over what's available on recent Nikon pro models. The Extra High option is new with the D90.|
Another nice feature: Active D-Lighting can be "bracketed" on the D90. Not in the usual sense of bracketing involving shooting with a range of settings (low, normal, and high, for example), but rather by simply grabbing one shot with Active D-Lighting off, and one with whatever setting you've chosen for it. If you're like us, and mistrust in-camera tonal tweaking, this is a very reassuring feature, and one that makes it more likely we'd use Active D-Lighting routinely.
Database-driven white balance
The D80 and D90 share the same 420-element RGB exposure/white balance sensor, but how they use is quite different. We mentioned above the new exposure system that uses the RGB sensor data for more accurate scene detection, letting it better match the exposure conditions it sees to its 30,000-image exposure database. The D90's different usage of RGB sensor data doesn't end with exposure determination though. Where the D80's white balance system uses the RGB sensor data to make a fairly conventional evaluation of color temperature, the D90 combines the RGB sensor's overall color information with the results of its scene matching to do a more intelligent job of light source identification. Beyond simply identifying the light source though, the scene database information can provide very direct information about the target color balance. One example of this is portrait shots: When the scene database recognizes that a portrait is being shot, its identification of the subject's face gives the white balance system a known color target. The actual color of the face in the scene then gives very direct information about the sort of light source illuminating it, letting the camera make a much more educated guess about its characteristics.
Here again, we'll have to wait for a production-level sample of the Nikon D90 to see how well this more advanced white balance system works. The real test will be how well it handles people shots under household incandescent lighting. The D80's auto white balance system (and those of most other DSLRs) does rather poorly under incandescent lighting. It will be interesting to see how the D90's white balance system handles difficult light sources; this could be an area of real differentiation between it and competing DSLRs.
Extensive Picture Control options
The D80 provided for user manipulation of the camera's imaging characteristics via the Optimize Image menu we'd seen over several generations of Nikon DSLRs now. More recently, Nikon has moved toward a Picture Control menu, as seen in their recent professional models. For the first time, the Nikon D90 will bring the Picture Control menu to a consumer DSLR, and with a few new options thrown in for good measure. The table below shows some of the new features:
|Nikon D90 Picture Control Menu Options|
|Set Picture Control takes the place of Optimize Image on the Nikon D90's Shooting Menu.||Previous models only had options for Standard, Neutral, Vivid, and Monochrome. The Nikon D90 adds Portrait and Landscape mode. Portrait and Landscape modes invoke color tweaks to favor their respective subjects.|
|Where the D80's Optimize Image control provided only a single set of image adjustments, you can tweak image settings for each of the Picture Control options independently of each other.||This is a neat display (reached by pressing the Thumbnails button to the left of the LCD while in the Picture Control menu): It gives a quick, at-a-glance view of where each of the Picture Control options is currently set, in terms of contrast and saturation.|
|In Monochrome Picture Control menu lets you choose color filters to apply before capture, just as you might have chosen color filters in B/W film days (a yellow filter for dramatic cloud/sky shots, for instance). You can also choose from among a number of hues to tone the resulting image with. (Thankfully including just plain black & white.)||Once you have a set of Picture Control tweaks dialed in just the way you want them, you can save it as a custom Picture Control option. A number of such custom presets can be saved. You can also load/save settings from/to the memory card, so you can easily set up a number of bodies with identical Picture Control options.|
"Smart" Exposure Program recognizes VR on/off
This is a minor point, but typical of the thoughtfulness Nikon applies to their cameras' operational details: When the D90 detects that a VR (Vibration Reduction) lens is attached, it automatically adjusts the program line of the exposure system to permit longer exposure times under dim lighting. With a VR lens attached, you'll thus be able to shoot at slower shutter speeds before the camera will want to pop up its flash. Slick.