Nikon D3X Exposure
Exposure Modes. Being a professional SLR, the D3X dispenses with Auto and Scene modes, and only gives you a choice between Program AE, Manual, Aperture Priority, and Shutter Priority exposure modes with shutter speeds from 1/8,000 to 30 seconds available, as well as a Bulb setting for longer exposures. As we've come to expect, while in Program AE mode, you can rotate the 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 feature, referred to as a "Flexible Program" mode, 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. You can also set the exposure step size for adjusting the shutter speed, to 1/3, 1/2, or one full EV unit, through the Custom Settings menu.
A useful feature when using Manual exposure mode is the electronic analog exposure display visible in both the viewfinder and LCD readouts. This shows the amount an image will be over- or underexposed, based on the settings you have selected, and helps you find the best exposure for the subject. I also liked the Command Lock feature (activated by pressing the Command Lock button on the top panel while rotating one of the command dials one click) which locks the shutter speed and/or aperture setting so that it is not accidentally changed when using the Command dial for another purpose. (If you set either the shutter speed or aperture before activating the Command Lock function on the D3X, a "lock" icon will appear next to the corresponding setting in both the viewfinder and data readout displays, and that setting can't be changed until you change the Command Lock option for that function.)
Sensor. As previously mentioned, the big news with the Nikon D3X is its brand new imager: a 24.5-effective-megapixel, full-frame, 35mm-sized CMOS sensor that yields double the pixel count of Nikon's D3. In terms of horizontal / vertical linear resolution, this equates to an increase of about 42% over the D3's sensor. Measuring 35.9 x 24mm, the sensor size is not the exact dimension of a 35mm frame, which measures 36 x 24mm, but it's very close. As an aside, it's also not quite the same size as the sensor used in the D3, which was 36 x 23.9mm. The native pixel dimension of a D3X image is 6,048 x 4,032, and the pixel size is 5.94 microns - down from 8.45 microns in the D3. From the fact that Nikon is not claiming to manufacture the sensor itself, it can be inferred that it has partnered with another company for the actual manufacture of the chip to Nikon specification. As with its past DSLRs, Nikon is remaining very tight-lipped about the actual manufacturer of the sensor used in the D3X, stating only that it is an "original Nikon design," and that no other company will ever be able to use it, nor will it appear in any other camera in the marketplace.
Realizing there was initially a lot of speculation about the origins of the D3X's sensor, Nikon has since clarified with this statement: "The Nikon D3X's 24.5-megapixel FX-format (35.9 x 24.0mm) CMOS sensor was developed expressly for the D3X in accordance with Nikon's stringent engineering requirements and performance standards, with final production executed by Sony. Featuring refined low-noise characteristics, 12 and 14 bit output, Live View capability and more, the D3X's unique sensor design was carefully blueprinted to perform in perfect concert with proprietary Nikon technologies including EXPEED Image Processing and the Scene Recognition System. Meticulous efforts allowed the sensor to become one of the many essential components and technologies which contribute to the D3X's superior image fidelity."
In terms of sensor type and absolute dimensions, the Sony Exmor sensor used in that company's flagship Alpha DSLR-A900 model is very similar; it too is a 35.9 x 24mm CMOS imager. Although Sony lists its camera as having 24.6-megapixel resolution, the image size of 6,048 x 4,032 pixels is identical -- the two companies just have a slightly different way of calculating effective resolution numbers. Nikon's D3X thus places right alongside Sony at the very top of the field among current 35mm full frame digital SLRs, at least in terms of resolution. Both Canon's flagship EOS-1Ds Mark III and EOS 5D Mark III lag behind somewhat in this area, with effective resolutions of 21.1 and 21.0 megapixels respectively. However, with 5.9 micron pixels, the Nikon D3X and Sony A900 have a smaller pixel size, while Canon's slightly lower-res cameras both have 6.4 micron pixels.
The earlier note about the D3x's sensor being an "original Nikon design" and that no other company will ever be able to use it may explain the dramatically higher image quality (particularly at high ISOs) of the D3x vs Sony's own A900 SLR, despite Sony being the fabricator of both chips.
Shutter. The Nikon D3's carbon fiber / Kevlar hybrid shutter mechanism is retained for the Nikon D3X, and plays a part in enabling the swift seven frames per second shooting offered in DX mode. The shutter mechanism is self-diagnostic, and is rated for a lifetime of some 300,000 cycles. Shutter lag (prefocused) is 45 milliseconds, according to our test measurements.
Processor. The Nikon D3X uses an EXPEED processor, as in the previous D3. The name is being used on all Nikon's digital cameras going forward from the D3 / D300, including the Coolpix point & shoot line. Nikon doesn't specify the exact model or speed of processor in each camera, though, so we can't state with certainty if the D3X's processor is completely identical to that of the D3. The processor in the D3X has a 16-bit pipeline and is the engine for processing the 14-bit color data from analog to digital at such a rapid rate. It also enables such impressive features as the Scene Recognition System, in-camera Lateral Chromatic Aberration Correction, and Active D-Lighting, detailed below.
Exposure Metering. Nikon has one of the most sophisticated and flexible metering systems on the market today. Like most SLRs, there are three main metering modes: Matrix, Center-Weighted, and Spot metering. Where Nikon's system differs is in the capability of these modes. Nikon's matrix metering is called 3D Color Matrix II, as it takes color as well as subject distance into account. (Note that the distance-recognition requires the use CPU-equipped lenses.) It covers a wide area of the frame. The D3X's Center-Weighted metering mode can be adjusted to give a weight of 75% to an 8, 12, 15, or 20mm dia. circle in center of frame, or an average of the entire frame. Spot meters a 4mm dia. circle (about 1.5% of frame) centered on the active focus area. (Most DSLRs only meter the very center of the frame in Spot metering mode, in the D3x, the metering spot can follow the active AF point around the frame.) There is an option in the B6 Custom menu that will allow you to fine-tune for optimal exposure in each of the metering modes separately. Exposure can be tuned from -1 EV to +1 EV in steps of 1/6 EV, and the exposure compensation icon is not displayed when this is in effect. The 1,005-pixel RGB metering sensor also serves to ascertain automatic white-balance, and provides assistance for focus tracking when the subject leaves the AF sensor area. A dedicated metering mode selector is provided for rapid changes of modes without resorting to menus.
Exposure Lock. The AE-L/AF-L button locks the exposure and/or autofocus, useful for off-center subjects in tricky lighting. It can be programmed for AE lock, AF lock, AE + AF lock, or various other functions via the custom menu. You can also program the button to toggle instead of requiring the button to be held.
Exposure Compensation. Exposure compensation on the D3X is adjustable from -5 to +5 exposure equivalents (EV) in 1/3, 1/2 or 1 EV step increments, and is controllable in all exposure modes. (Though in Manual exposure mode, only the exposure information shown in the electronic analog exposure display is affected; actual shutter speed and aperture do not change.) The D3X also offers what the company calls "Easy exposure compensation", where the exposure compensation button does not have to be pressed before turning a dial to adjust EV compensation in Program, Aperture-priority or Shutter-priority modes, and where the previous value is remembered after the exposure meter turns off. The Auto Bracketing feature on the Nikon D3X takes as many as nine shots of the same subject with varying exposure values determined either by the photographer in Manual mode or by the camera in all other modes. Exposure settings for bracketing can vary up to -4 to +4 EV (values are added to the already chosen exposure compensation value), with step sizes of 1/3, 1/2, 2/3 or 1 EV unit, and the bracketing biased toward either underexposure, overexposure, or centered around the main exposure value. Through the Custom Settings menu, you can designate whether the bracketing sequence adjusts the ambient exposure, the flash exposure, both flash and ambient exposures, or white balance, and the bracketing order can also be specified.
Multiple Exposures. The D3X supports multiple exposures (not to be confused with image overlay in the Retouch menu, which allows you to combine any images after they have been recorded). In Multiple Exposure mode, up to 10 successive images can be recorded in the same frame, and there is an Auto gain feature which will adjust exposure of each frame according to the number of frames (examples would be 1/2 gain for 2 frames, 1/3 for 3 frames, etc.) Nikon recommends to turn Auto gain off if the background is dark. If Single Frame drive mode is selected, the shutter release needs to be pressed for each image. If Continuous High or Continuous Low mode is selected, the camera will record all exposures in a single burst.
Scene Recognition System. Nikon's Matrix metering system went through quite an overhaul for the D3, and gained a new name in the process: the Scene Recognition System. A new diffraction grating over the 1,005 area metering sensor allowed more accurate detection of color and brightness. At the same time, new firmware was capable of more complete analysis of scenes, improving white balance, focus tracking, and exposure. One of the chief benefits of the Scene Recognition System was highlight analysis, designed to prevent blown highlights in common situations by adjusting the tone curve to compensate. The Nikon D3X inherits the improved Scene Recognition System functionality from its sibling.
ISO Sensitivity. ISO ranges from 100 to 1,600 and can be extended down to ISO 50 (Lo 1), and up to ISO 6,400 (Hi 2). On the D3, ISO range was 200 to 6,400, expandable 100 to 25,600. ISO can be adjusted in 1/3, 1/2 or 1 EV steps, depending on Custom Menu b1. Nikon's excellent Auto ISO feature is carried over as well, which allows you to set both the upper ISO limit as well as the minimum shutter speed (selectable from 1s to 1/4000s) required before ISO is increased automatically. While it doesn't quite equal the D3's incredible high-ISO capability, we were very pleasantly surprised by the quality of the D3x's images shot at high ISO values, particularly in light of its much greater pixel density.
White Balance. The D3X offers the usual white balance settings: Auto, six presets consisting of Incandescent, Fluorescent, Direct Sunlight, Flash, Cloudy, Shade; a manual mode where white-balance is determined from a white or grey card, and a Kelvin temperature setting which is selectable from 2,500 to 10,000K in 31 steps. The Fluorescent preset has seven sub-settings consisting of Sodium Vapor (2,700K), Warm-white (3,000K), White (3,700K), Cool White (4,200K), Day White (5,000K), Daylight (6,500K), and High Temperature Mercury Vapor (7,200K); and the manual setting allows up to four custom white-balance measurements to be stored. All the presets and manual settings are tweakable via a 2D fine-tuning grid display as shown on the right. The D3X also supports White Balance bracketing, where two to nine frames can be bracketed with Blue or Amber white balance bias increments of 5, 10 or 15 mireds.
Active D-Lighting. D-Lighting has proven a popular post-processing feature in Nikon's consumer digital SLRs, as well as some of the company's point & shoot models. It's a quick software process that attempts to overcome underexposed images, and bring detail out of shadows. An improved version of Active D-Lighting appeared in the Nikon D3 and D300, including optimization of image contrast, helping to prevent over-processing of shadows and flattening of overall image contrast. As with the Scene Recognition System, the D3X inherits Active D-Lighting from the D3 and D300 -- but this time with a slight improvement, in that as well as the previous High, Normal, Low or Off settings, the D3X also offers an Extra-High setting, or the ability to let the camera automatically choose the Active D-Lighting strength on the fly.
Lateral Chromatic Aberration Correction. While other cameras have had lens distortion processing built-in in the past, notably the Olympus E-1, none until Nikon's D3 and D300 did the processing based on the distortion detected in the image. Past cameras (and most distortion-correction software) simply looked at which lens was mounted and perhaps the focal length if it was a zoom lens, and then applied a pre-set amount of correction; no image analysis actually took place. Nikon's Lateral Chromatic Aberration correction offered a more sophisticated approach, thanks to power of the camera's EXPEED processor, by actually analyzing each image after capture and fixing the chromatic aberration detected therein before saving the JPEG file. Cameras with full-frame, high-resolution sensors place a greater demand on lenses, and hence Lateral Chromatic Aberration correction proves a particularly useful feature on the D3X. There are no settings for this feature; it's always enabled for JPEGs. (And the D3x's RAW files correctly have no distortion processing applied to them.)
Vignette Control. Another interesting feature is Vignette Control, first seen in firmware upgrade v1.11 for the D3, and then in the Nikon D700. Three levels are available that attempt to reduce the effects of corner shading with certain lenses. Designed for G and D Nikkor lenses, not DX or PC lenses, users can choose from High, Normal, Low, and Off for this setting. You can't see the results in Live View, nor can the Vignette Control be applied to multiple exposures. As with the chromatic aberration discussed in the previous section, vignetting is more likely to be an issue with full-frame digital imaging -- hence this is a very worthwhile feature.
Picture Control. Nikon has standardized its Picture Control system so that camera settings for sharpening, contrast, brightness, saturation and hue can be finely adjusted and ported to other Nikon digital SLRs that support the system. The D3 was the first camera compatible with the option, and the Nikon D3X likewise follows the standard. There are four presets called Standard, Neutral Vivid and Monochrome, plus up to nine custom presets can be defined, named, saved and copied. Sharpness can be adjusted in ten steps, along with an Auto setting; contrast, saturation and hue can be adjusted in seven steps, while hue is adjustable in three steps. There is also a five-step "Quick Adjust" setting which exaggerates or mutes the effect without having to adjust each slider individually. When Monochrome Picture Control is selected, Hue and Saturation are replaced by Filter Effects and Toning respectively. Filter Effects offers Off, Yellow, Orange, Red, and Green settings, while Toning offers B&W, Sepia, Cyanotype, Red, Yellow, Green, Blue Green, Blue, Purple Blue and Red Purple settings.
Noise Reduction. The D3X offers four levels of high ISO noise reduction: Off, Low, Normal and High. For Low, Normal and High settings, noise reduction is performed at ISO 500 and higher. When set to Off, minimal noise reduction is performed at ISO 2000 and above. No high ISO noise reduction is performed on RAW files (other than on the embedded JPEG thumbnail). The D3X also offers long exposure noise reduction. When set to On, the camera takes a second exposure for the same duration with the shutter closed, and subtracts the "dark frame" from the first, to reduce hot-pixel and amp noise for exposures longer than 8 seconds.
Release Modes. The D3X's release modes are selected by a dial, located on the top panel, on the left side. Single Frame (S) mode takes one shot each time the shutter-release is pressed. The Nikon D3X's Continuous High (CH) mode is rated by Nikon for up to 5 frames per second for a total of 44 Large/Fine JPEG or 24 12-bit RAW (lossless compression) before the buffer fills and the camera slows. Of course, the number of consecutive shots could be limited by CompactFlash space, if your memory card(s) are nearly full. Also, when shooting JPEGs of a very complex scene with a lot of sharp, fine detail, the resulting images may also compress less and result in lower buffer capacities. For 14-bit RAW files, the frame rate drops to only 1.8 frames per second, which is a bit of a surprise, as the D3 managed full speed when it was used in 14-bit mode. In DX crop mode, the D3X's maximum frame rate in Continuous High mode jumps to 7 frames per second for JPEGs or 12-bit RAW files, but drops to about 2.6 frames per second for 14-bit RAW. Through the D3X's d2 Custom menu, you can program the maximum shooting speed in Continuous High mode to 5, 6 or 7 fps (valid only for DX crop mode, as the maximum frame rate for other formats is limited to 5 fps), and Continuous Low from 1, 2, 3, 4 or 5 fps. The maximum burst size can also be programmed in the d3 Custom menu, with values ranging from 1 to 130.
The camera's Release Mode dial also accesses the Self-Timer mode, which can open the shutter 2, 5, 10 or 20 seconds after the shutter button is pressed, as well as Live View mode, and Mirror Up mode. Live View simply switches the camera to Live View mode. In Live View mode, press the shutter once to initially raise the mirror and open the shutter; each time you press it after that captures an image (momentarily dropping the mirror) and then returns the camera to the Live View state again. Mirror Up is used to minimize blur due to minute vibrations caused by mirror slap. When activated, the first press of the shutter release raises the mirror, while a second press trips the shutter.
Interval Timer Mode. Another useful feature on the Nikon D3X that first appeared all the way back on the D2H is Interval Timer mode, which facilitates time-lapse photography by taking a series of images at preset intervals. You can set the starting and ending times for the series, as well as the amount of time between shots and the total number of shots to be captured. This is a good way to capture a timeline of slower events, such as clouds passing across the sky, tidal changes, a flower opening, etc.