Nikon Z7 Review

Nikon launched the Z7 as a mirrorless equivalent of their D850 reviewed here
Nikon D850, which is one of the most highly-acclaimed Full-Frame DSLRs for all times. The D850 aggregates decades of development and refinement to deliver an extremely well-round feature-set with impeccable performance. That is a very high bar to set for a first-generation product on an entirely new platform. It might be impossible to beat on all front, yet the Z7 even delivers capabilities beyond the D850, with others not quite matching it.

At its heart, the new Nikon Z7 features a 46 megapixels Full-Frame BSI-CMOS sensor developped using the same technology as the sensor in the D850. Both sensors are designed to capture extremely sharp details and hence neither is covered by an Anti-Alias Filter. The difference though is that the Z7 sensor offers a 493-Point Phase-Detect AF system built right into the sensor. Of course, the D850 being a DSLR, needs to such system and instead uses a dedicated Phase-Detect AF unit in its mirror chamber. There are adantages to both way of implementing Phase-Detect AF but dedicated units are almost certain to focus faster and with less light. Built-in Phase-Detect AF, on the other hand, never needs calibration as it always focuses exactly on the sensor-plane.

The fast EXPEED 6 processor in the Z7 allows it to continuously capture full-resolution images at a speedy 9 FPS. This slows down to 5.5 FPS when using both continuous autofocus and auto-exposure. The sensor and processor combination also allow for full-width 4K Ultra-HD video capture at 30 FPS.

There are very few features that the D850 and Z7 do not offer. The most notable on is the absense of a built-in flash, although professionals rarely use one given the unnatural look that results. External lighting is supported via a standard hot-shoe but the Sync-Port of the D850 is gone on the Z7. The main addition to the Z7 is an extremely advantageous one: a built-in 5-axis image-stabilization system effective to 5 stops over hand-holding.

This 5-axis Image-Stabilization System compensates for horizontal and vertical shift plus pitch, yaw and roll rotation to compensate for camera shake. Having such a system in-body allows every lens to be stabilized, including bright primes, fisheye and tilt-shift lenses, providing entirely new capabilities to Nikon interchangeable lens cameras, something that nearly every other ILC brand has been doing for years now. Nikon even implemented their own form of Dual IS which separates the axis of stabilization between body and lens for lenses with built-in Vibration Reduction. At this point, it is unknown if this works when using adapted third-party lenses, as there are no native third-party Z-mount lenses.

Being mirrorless, the Nikon Z7 operates much more quietly than a DSLR. There is still a mechanical shutter that covers a 1/8000-30s shutter-speed range. This mirrorless offers a Electronic Front-Curtain Shutter which operates by fullushing the sensor electronically and closing the mechanical shutter at the end of the exposure to perform the read-out. This reduces the amount of camera vibration which should reduce shake-induced softness. To further reduce shake, Nikon offers the same Shutter-Delay options as on the D850, a customizable pause of 0.2-3s between the time the shutter-release is pressed and the mechanical shutter opens, allowing vibration to settle down before exposure starts.

Nikon kept their class-leading Interval Timer in the Z7. The Interval Timer is controlled separately from drive modes. One can specify the number of intervals and the number of shots taken at each interval. With AEB, this can be used to create an HDR time-lapse. The interval can be between ½s and 24h and number of intervals between 1 and 9999. Between 1 and 9 shots can be taken at each interval. A Start Time can be specified up to 1 week in advance even. There are the same options as on the D850:

• Exposure Smoothing - This option, available for Time Lapse Video, dampens changes in exposure between shots. This reduces Automatic Exposure changes between shots to smooth transitions.
• Silent Photography - Forces the use of the electronic shutter to reduce noise from the camera.
• Interval Priority - This decides whether the interval or the shutter-speed has priority. When Interval Priority is On, images are always taken at the given interval, even if more time is required for the exposure.
• Starting Storage Folder - Allows the sequence of images produced to be stored in a folder separately from other images and videos.

There is a separate Time Lapse feature which automatically creates a video from a series of frames. The interval between frames can be selected from 1s to 10m in 1s increments, while the total capture time can reach up to 8 hours. Intelligently, this digital camera warns in advance if sufficient memory is not available. Time Lapse video are rendered at the selected movie resolution and frame-rate. Crucially tough, they are framed at a 16:9 aspect-ratio. An Exposure Smoothing option makes changes in Auto Exposure more gradual during recording of a Time Lapse Video. Time Lapse Video inherits the same Silent Photography and Interval Priority options as the Interval Timer. The maximum resolution supported by Time Lapse Video is 4K Ultra-HD. In order to produce 8K Time Lapses, one must use the Interval Timer and assemble the resulting 3:2 aspect-ratio images by software.

Focus Bracketing which Nikon calls Focus Shift made its way to the Z7 with the same a class-leading level of sophistication as on the D850. The camera can take up to 300 shots, changing focus between shots by a selected increment on a 1-10 linear scale. The interval between each shot can be set from 0 to 30 seconds in one second increments. Nikon mentions the need to set interval when using a flash, so that it has time to recharge between shots. Just like with the Interval Timer, there are options for Exposure Smoothing, Silent Photography and a Starting Storage Folder.

Four metering patterns are available on this mirrorless: Matrix, Highlight Weighed, Center-Weighed/Average and Spot. Highlight Weighed, introduced on the Nikon D810
Nikon D810, provides a segmented metering system that gives priority to highlights. Spot is for Spot metering. Depending on a custom setting, the third choice activates Average or Center-Weighed metering. Note that the center-area of Center-Weighed metering is no longer resizable.

Auto-Exposure Bracketing can be enabled for 2 to 9 frames with steps up to ±3 EV when taking 5 frames or less. One can bracket exposure parameters, flash or both. Virtual Bracketing for WB or Adaptive D-Lighting can be performed instead with 3 step sizes for WB and 5 for ADL. In both cases, only one photo is taken but it is rendered multiple times. For obvious reasons, Virtual Bracketing only applies to JPEG.

Standard ISO sensitivities run from 64 to 25,600. Expanded ISO values are identified by label. ISO 32 is called L 1.0. ISO 51,200 is called H 1.0 and ISO 102,400 is called H 2.0. Half-stops or third-stops are available. Auto ISO is configured by specifying a maximum ISO sensitivity, plus a minimum shutter-speed. The Z7 then adjusts the chosen ISO within the permitted range to obtain at least the specified shutter-speed.

Just as on the D850, there are three types of Automatic White-Balance. One attempts to render whites as neutral, one tries to make them look natural and the last preserves warm lighting. Other White Balance options are quite numerous. There are 6 presets With 7 sub-types for Fluorescent: Sodium-Vapor, Warm-White, White, Cool-White, Day-White, Daylight, High Temperature Mercury Vapor.. Custom WB now has 6 memories. Each nicely shows a thumbnail of the image from which it was recorded. A small selectable area can be sampled. Kelvin WB can be selected between 2500K and 10000K. WB Fine-Tuning offers two axis except for Kelvin which only supports the G-M axis. Regardless, there are always 49 steps along G-M and 25 along B-A. The temperature span along each axis is actually the same, only Nikon allows ¼-point for one and ½-point increments for the other.

This camera features Nikon's Active D-Lighting image processing technology which lightens up dark areas of images to bring out details. There are 5 levels of ADL which differ by how much shadows get boosted. ADL can be manually or automatically set to one of those levels or turned off entirely. ADL indirectly affects RAW capture because exposure is adjusted according to the selected ADL level.

The Nikon Z7 can capture JPEG or TIFF images and RAW files, using the Nikon NEF format. RAW files may be uncompressed, losslessly compressed or compressed with loss. Lossless compressive saves on average 40% space without any drop in quality, so this is the recommended option. Optionally, RAW depth can be reduced to 12-bits per pixel, down from 14-bits per pixel. This saves 20% storage space at the expense of 2 stops of precision.

Unlike its DSLR inspiration, the Z7 is less of an action camera. Its buffer holds only 25 JPEG images or 18 RAW files. This is enough for very short bursts. The buffer does clear very quickly though thanks to the exclusive use of XQD memory. Another loss compared to high-end DSLRs is that the Z7 features just a single memory card slot in order to keep the camera relatively compact.

The new all-electronic Z-mount is designed to allow extremely sharp optics with large maximum apertures. In the long term, the success of this new platform will determine if and when this goal gets realized. For the moment, there are just three native Z-mount lenses. This includes a versatile 24-70mm F/4 zoom and two F/1.8 prime lenses. To encourage existing Nikon DSLR uses to adpot this, Nikon built a dedicated F-to-Z mount which is said to allow maximum peformance to be retained in the majority of lenses. Autofocus is only supported for AF-S lenses as the adapter does not feature mechanical couplings.