Nikon D90 Optics
Nikon D90 Optics
Like other Nikon SLRs, the D90 accommodates a wide range of Nikkor lenses, via the standard Nikon "F" lens mount. With very few exceptions, you can use the Nikon D90 with any F Mount Nikkor lens ever made, but older non-CPU lenses will significantly limit your exposure options. (Like the D80, the Nikon D90 lacks the "Non-CPU Lens Data" menu item found in Nikon's higher-end DSLRs, as well as the indexing finger the D300 has for wide-open metering with older "AI" lenses. If you have any AI lenses you want to be able to use the camera's metering system with, you should go with the D300 rather than the D90.)
As seems to becoming almost standard with Nikon, they've announced a new kit lens along with the D90. Their latest kit offering for the D90 is the AF-S DX 18-105mm f/3.5-5.6 G ED VR, with 15 elements in 11 groups one element using ED glass and one hybrid aspheric surface. (A hybrid aspheric lens consists of a normal spherical-section glass lens with a thin plastic layer bonded to it that provides a molded aspheric surface. They provide the benefits of aspheric surfaces (reduced distortion and aberration) at lower cost than all-glass aspherics.) Maximum aperture ranges from f/3.5-5.6 from wide angle to tele, while minimum aperture ranges from f/22-36.
The long list of alphabetic jargon in the lens's name deserves some translation for the non-Nikonians who might be reading this, so here it is:
- AF-S - "Silent Wave" (SWM) motor for fast, quiet focusing. This design also lets you adjust focus manually after the autofocus system has achieved focus, handy for manually tweaking focus to your liking in tricky situations.
- DX - designed to mate with Nikon's DSLRs, smaller and lighter because its image circle doesn't have to cover the full 35mmm film plane.
- 18-105mm - A fairly wide zoom range, 5.8x from wide to tele, equivalent to a 27-157.5mm lens on a 35mm camera.
- f/3.5-5.6 - A fairly average maximum aperture range, typical of most of Nikon's kit lenses.
- G - It has a CPU so it will work with Nikon's 3D Color Matrix Metering II system. The G also means no aperture ring, you set the aperture only through the camera's controls. Speaking of aperture, the diaphragm in this lens is a 7-blade rounded-opening design, for nice round catchlights and more appealing bokeh. (A more natural blur for out-of-focus objects.)
- ED - Uses Extraordinary Dispersion glass for better control of distortion, astigmatism, and chromatic aberration. As noted, there's also one aspheric surface, down from no fewer than 7 in the previous 18-135mm kit optic.
The new lens focuses quite closely, to a maximum repro ratio of 0.2x (1:5 macro), and accepts 67mm filters. This is a slightly reduced macro capability over the previous 18-135mm, which could get to 0.24x. It's nice that the lens takes a 67mm filter, that seems to be a fairly common size on Nikon's lenses, so you'll have a better chance of using the same filters on multiple lenses. As its VR designation indicates, this lens also incorporates Nikon's excellent Vibration Reduction (Image Stabilization) technology. The overall dimensions of the lens are 76mm diameter by 89mm long, and it weighs in at 420 grams. This lens adds $300 to the price of the body when purchased as a kit, but will cost $485 when purchased alone.
The new kit lens felt very nice in the hand. It zoomed smoothly, focused quickly, and construction was solid and tight. Optical performance was quite good, and VR is a welcome addition. Along with the test results presented below, see our full review of the Nikkor 18-105mm VR lens on our sister site, SLRgear.com.
As noted above, functions and exposure modes available with a given lens will vary greatly with the lens type. More recent Nikkors (the G- or D-type models) include a microchip (CPU) that communicates focal-distance information to the camera. Lenses without the microchip won't support the 3D Matrix metering mode, and in fact all metering is disabled on the D90 when using a non-CPU lens. Most non-CPU lenses can be attached to the camera, but the shutter release will be disabled unless the camera is in Manual exposure mode, and AF, metering, electronic analog exposure display and TTL flash control can't be used.
For complete lens-compatibility information, see the tables below (courtesy of Nikon):
Kit Lens Test Results
Very good performance with the 18-105mm VR (Vibration Reduction) kit lens.
The Nikon D90 digital SLR accommodates a wide range of Nikkor lenses. Here, we tested the performance of the new 18-105mm VR kit lens, which has a fairly generous (for a kit lens) optical zoom range of ~5.8x. Details are very good at wide angle, with better-than-average corner-to-corner sharpness (only slight softness in the extreme corners) and relatively low levels of coma distortion and blurring in the corners. Chromatic aberration is also quite low for a long ratio zoom (see below for why). Results at full telephoto are also very good, with good sharpness across the frame and very low levels of chromatic aberration, though pin-cushion distortion is quite evident. All in all, the Nikkor 18-105mm VR, does very well for a kit lens on a 12-megapixel sensor, and the added image stabilization will come in handy for low-light shooting.
A average area (for an SLR kit lens), with good detail. Flash throttles down well.
|Standard Macro with 18-105mm VR
|Macro with Flash|
As with zoom performance, the Nikon D90's macro performance will depend entirely on the lens in use. However, with the 18-105mm VR kit lens set to 105mm, the D90 captured a fairly average minimum area (for a non-macro, long zoom SLR lens) measuring 4.23 x 2.81 inches (107 x 71 millimeters). Resolution is high, though details are a little soft overall, even at the center of the frame, with moderate softening in the corners. (Most lenses have some softening in the corners at macro distances.) The Nikon D90's flash throttled down for the macro area pretty well, and there was no detectable shadow from the lens barrel, resulting in a good exposure with the flash.
Moderately high geometric distortion with the 18-105mm VR kit lens.
|Barrel distortion at 18mm is 1.1 percent|
|Pincushion at 105mm is 0.5 percent|
The Nikon D90's 18-105mm VR kit lens produced about 1.1 percent barrel distortion at wide-angle, which is higher than average among the cameras we've tested, and noticeable in its images. At the telephoto end, the 0.5 percent pincushion distortion is also above average and quite noticeable. This is the tendency for the lens to bend straight lines outward (like a barrel -- usually at wide-angle) or inward (like a pincushion -- usually at telephoto).
Very low in camera JPEGs, but moderately high at wide-angle in RAW files with the 18-105mm VR kit lens.
Chromatic aberration in the corners of camera JPEGs taken with the Nikon D90's kit lens is extremely low, and hardly noticeable at either wide angle or full telephoto. So low in fact, that it made us wonder if the D90 was correcting for it, even though Nikon hasn't advertised chromatic aberration correction as a feature for the D90. (This distortion is visible as a slight colored fringe around the objects at the edges of the field of view on the resolution target.)
As we suspected, there were moderate to high levels of C.A. in the corners of converted RAW files. So, it turns out the Nikon D90 does indeed compensate for lateral chromatic aberration in its JPEGs, just like its big brothers: the D3 and D300. As mentioned above, this feature was not listed in any of the pre-release D90 info received, nor was it mentioned on the Nikon USA website at the time of this writing. We were pleasantly surprised, to say the least.
Chromatic Aberration Reduction. As noted, the anti-CA system in the D90 seems to work identically to that in the D3 and D300. The crops above were taken from the corners of converted RAW files with the D90 and the new 18-105mm VR kit lens. It's a very good kit lens for the price, but there's some moderate to strong CA in the corners, as can be seen clearly in RAW files, as above.
In the previous set of in-camera JPEGs, you can still see a tiny amount of coloration along the vertical edges of the bold black bar, but that's really splitting hairs: For all intents and purposes, the chromatic aberration is gone. (Note that the anti-CA processing is only applied to the in-camera JPEGs; the camera very rightly leaves the RAW files untouched.)
It's important to note that this CA correction isn't dependent on your using a Nikon lens: The camera figures out how much CA there is in each area of the image, and shifts the planes of red and blue pixel data to compensate for it. Note, though, that this only works for lateral CA. Longitudinal chromatic aberration isn't corrected out. (Happily, with most good quality lenses, lateral CA is much more common than longitudinal.)
Slight blurring in the corners of the frame at both zoom settings with the kit lens.
|Wide: Slightly soft in the
corners (upper left).
|Wide: Sharper at center.|
|Tele: Slightly soft in the
corners (upper left).
|Tele: Sharper at center.|
The Nikon D90's 18-105mm VR kit lens produced slightly soft corners in a few shots. At wide angle, corners on our test targets had a little softness compared to the center. At telephoto, corner softness was similar, but still much less than average for a kit lens. A very good performance here, especially considering these shots were taken at maximum aperture (corner softness usually improves when the lens is stopped-down a few f-stops). Impressive results for a 5.8x zoom kit lens.
The images above were taken from our standardized test shots. For a collection of more pictorial photos, see our Nikon D90 Photo Gallery .