Review: Pentax 645Z Medium Format DSLR Camera

The Pentax 645Z Medium Format DSLR Camera features a 43.8 x 32.8 mm CMOS sensor with 51.4 effective megapixels.

The sensor is designed without an anti-aliasing filter to maximize sharpness and details. RAW files can be recorded at 14-bit and saved using either the proprietary PEF format or Adobe's DNG format.

Unlike the Pentax 645D that the Pentax 645Z replaces, the new camera has a Sony CMOS sensor, which should be good news for noise control.

There are a few other significant upgrades. The maximum sensitivity setting, for example, is now ISO 204,800, significantly higher than the ISO 6400 maximum offered by most other medium format cameras. An ISO range from 100-204,800 and high S/N ratio provides low noise, low light capability, and the Prime III image processor lends itself to fast image capture with a maximum of 3 fps continuous shooting. The SAFOX II autofocus module utilizes 27 autofocus points including 25 cross-type sensors and 3 AF sensors dedicated for low light focusing. The new Real Time Scene Analysis System features an 86,000 pixel RGB light-metering sensor for enhanced accuracy of exposure, white balance, and auto-focusing.

There's also a tilting 3.2-inch 1,037,000-dot LCD screen which is capable of showing a Live View image and Full HD 1080 60i/30p/24p video capture is supported in the H.264 format with a dedicated button for instant switchover from stills to video. An external microphone jack enables high quality audio recording with manual sound level control and monitoring. An HDMI port outputs HD images to HDTVs and a USB 3.0 jack enables fast image transfer to your computer. Interval recording for time-lapse videos is supported with an output of UHD 4K resolution.

A 3.2", 1037k-dot, tilting, air-gapless, LCD monitor enables live view composition and playback viewing from a various angles and a trapezoid-shaped glass prism viewfinder with Kepler telescope-type eyepiece unit provides traditional eye-level composition. The design of the viewfinder also helps to achieve the relatively compact size of this medium format camera. The 645Z is extremely durable with an aluminum alloy chassis, magnesium alloy shell, and 76 specific weather seals to keep out moisture and dust. It is a camera designed for field as well as studio and can operate in temperatures from 14-104°F.

In addition to the built-in stereo microphone, the 645Z has a stereo mic port and audio level control is possible.

Pentax has also given the 645Z the SAFOX 11 phase-detection autofocus (AF) system found in the K-3. This has 27 AF points, 25 of which are the more sensitive cross-type. It's also capable of working down to -3EV.

Exposure can be controlled manually or automatically with information being provided by the Pentax Real-Time Scene Analysis System. This consists of an 86,000-pixel RGB light-metering sensor and an algorithm. Pentax claims this improves on exposure-control accuracy and it provides data to enhance autofocusing accuracy and white-balance adjustment.

There are also two SD/SDHC/SDXC card ports, with the second port compatible with Flu cards to allow wireless shutter release and image transfer and via a smartphone.

Price:

Product Highlights

51.4MP CMOS Sensor - 43.8 x 32.8 mm
Prime III Image Processor
Anti-Alias Filter-Less Design
3.2" 1037K Dot Tiltable Air-Gapless LCD
Full HD 1080 60i/30p/24p Video Capture
ISO Sensitivity Range of 100 - 204,800
SAFOX II TTL 27 Point Autofocus System
3 fps Continuous Shooting
Weather Sealed Magnesium Alloy Body
Pentax Flucard and Eye-Fi Compatible

Pentax 645Z Review by Mike Tomkins

Sensor. The most important new feature of them all for the Pentax 645Z is at its very heart, and shared by rivals Phase One and Hasselblad: The same 50+ megapixel image sensor seen in the recently-launched Hasselblad H5D-50C and Phase One IQ250. By way of comparison, the 645D used a 40-megapixel chip, so all other things being equal, linear resolution should have increased by about 14%. Sensor dimensions are 43.8 x 32.8mm, and as shown above right, that's quite a bit bigger than a 35mm full-frame sensor.

It's a Sony CMOS chip, which is in itself big news. The 645D used a Kodak-sourced CCD sensor, but in the runup to the one-time film giant's bankruptcy, it sold its image sensor business. The simultaneous switch to CMOS means that for the first time, the 645D is capable of offering a live-view feed on its rear-panel display, if you want an alternative to the TTL viewfinder. That's handy given the new articulated LCD panel, and it also allows for movie capture. But more on those in a minute.

For Pentax, due to slightly different masking from Hasselblad and Phase One, it's classed as a 51-megapixel chip, rather than the 50-megapixel rating in the rival cameras. It has exactly the same 5.3 micron pixel size, though, and the same manufacturer-claimed 14 stops of dynamic range. And just like in the original 645D, there's no antialiasing filter to rob the sensor of its finest resolution. That means you'll want to watch out for moiré / false color in fine patterns, but it also means you get the most out of the sensor. (And for pros, that's probably more important than occasional moiré.)

Processor. The new image sensor is coupled to a PRIME III image processor, as first seen in the Pentax K-3. Compared to the PRIME II processor of the 645D, Ricoh says the new variant is approximately five times faster. That extra horsepower manifests itself in a couple of ways.

Performance. Firstly, there's been a handy step forwards in terms of burst shooting speed. The Pentax 645Z still won't win any awards for burst rate, and it's clearly not a camera aimed at sports shooters. With a manufacturer-specified burst rate of three frames per second at full resolution, it still provides only half the performance of the company's entry-level APS-C DSLR in that area.

But then, given the extremely high resolution and the fact that you're talking about a medium-format image sensor, you really can't expect blazing performance. It's likely fast enough, though, and that's what counts. The 645Z's 3 fps is close to triple the 1.1 fps provided by the original 645D, and double or more the speed of Hasselblad and Phase One's competing medium-format models.

And despite the increase in speed and resolution, buffer depth has also doubled if you're shooting in JPEG mode, with a total of 30 JPEG frames now possible in a single 3fps burst. Raw shooters will manage 10 frames, down just slightly from the 11-frame buffer of the 645D.

One other performance improvement of note is that, where you had to wait a full 2.3 seconds to review each image you'd shot with the 645D, the Pentax 645Z will show its higher-res images to you in just 0.9 seconds after capture.

Sensitivity. Together, the sensor and processor also provide an absolutely whopping step forward in terms of sensitivity. With a range of ISO 100 to 204,800 equivalents on offer, the Pentax 645Z matches the Canon EOS-1D X and Nikon D4 -- but it does so with a much larger sensor, which should hopefully translate to better noise levels if you downsample your images to the same resolution as either camera. And that's comparing to full-frame. Compared to other medium-format models, there's simply no competition. The 645D topped out at just ISO 1,600, while Hasselblad and Phase One won't allow anything over ISO 6,400 from the same sensor.

It remains to be seen how the 645Z does in the real world, and we have to note that we've yet to see any high ISO output from the camera. If it does as well as we're hoping, though -- and Ricoh is clearly confident, not hiding any portion of this sensitivity range behind an ISO expansion function -- then this could be big news for low-light shooting with medium format.

Lens mount. As with its predecessor, the Pentax 645Z sports a 645AF lens mount compatible with DA645, D FA645, FA645 and A645 lenses. Courtesy of an optional adapter, you can also mount Pentax 67 lenses.

Lenses. While the mount itself is unchanged, there's a big development on the optics front. Although the 645D has been a great option for existing 645 shooters, the selection of lenses in the US market has been limited, to say the least. Only three new lenses have reached market since that camera began shipping, and while many other lenses were still in production and readily available in the Japanese market, they weren't really making it stateside.

That's now been rectified, and counting lenses originally designed for film, Pentax 645D and 645Z shooters now have a total of 17 lenses (12 primes and five zooms) to choose from, plus three more zooms still on the roadmap. Everything from 33mm to 300mm is covered without gaps by the zoom offerings, while the primes range from 25mm to 400mm. If you prefer to think in 35mm-equivalent focal lengths, that's everything from 26mm to 236mm-equivalents covered by the zooms, and 20mm to 315mm-equivalents by the primes.

And among these are five f/2.8 primes, while the zooms are all constant-aperture types with either an f/4.5 or f/5.6 maximum aperture. Drawbacks to the newly-available FA-series lenses are that they lack weather-sealing, SDM autofocus motors, or image stabilization. Instead, they're all screw-drive, unstabilized lenses. (In fact, there's only one stabilized lens available for the 645-series cameras, full stop -- the HD Pentax-D FA645 Macro 90mmF2.8ED AW SR.)

Lens correction. Like its predecessor, the Pentax 645Z sports in-camera lens correction, allowing it to correct for distortion and lateral chromatic aberration. However, it can now also correct for peripheral illumination and diffraction, taking it a step beyond the 645D's capabilities. The function works with DA645, D FA645 and FA645 lenses, but not with A645 or adapted 67 lenses.

Dust removal. If you regularly change lenses, you can expect dust to get inside your camera sooner or later. (Most likely, sooner.) Ricoh has retained the same DR II dust removal system used in the 645D for the new Pentax 645Z. It uses a piezoelectric element that vibrates the sensor cover glass at high frequencies, shaking free any stuck dust particles.

To help you decide when a more detailed cleaning is needed, the Pentax 645Z also retains its predecessor's dust alert function, which helps you to locate stubborn dust particles on the sensor for manual cleaning.

Metering. The Pentax 645Z sports a new metering sensor, or at least new to medium-format: Ricoh was able to share technology -- and development cost -- with its APS-C flagship DSLR, the Pentax K-3.

Gone is the 77-segment metering sensor first introduced with the K-7 back in 2009. In its place, the 645Z sports a much finer-grained 86,000 pixel RGB CCD metering sensor.

That's more than 1,100 pixels for every segment that was on the earlier sensor, which allows for much more precise metering. And since it's an RGB chip, it can also recognize color information, allowing it to help out with subject identification.

Branded as the Real-Time Scene Analysis System, this metering system also has a wider working range of -1 to 21 EV with a 55mm f/2.8 lens at ISO 100. By comparison, the earlier sensor had a range of EV 2 to 21, making it rather less sensitive in low light.

Although the new sensor is much finer-grained, the choice of metering modes is unchanged from earlier cameras: Multi-segment, Center-weighted, or Spot. An exposure lock function is available, accessed with the AE-L button at the top right corner of the camera's rear, nestled in the top of the thumb grip. You can also specify up to +/-5EV of exposure compensation in 1/3 or 1/2EV steps, and bracket 2, 3, or 5 exposures.

Autofocus. Another area in which Ricoh has made a big step forward is in the 645Z's autofocus system. Here, too, tech was shared with the Pentax K-3: The 645Z inherits the exact same SAFOX 11 autofocus sensor used in that camera. As in the 645D, though, these points are clustered at the center of the frame, and don't extend near the edges. That's a function of the fact that the AF sensor assembly was designed for an APS-C sensor.

Still, SAFOX 11 represents the first major step forwards since the SAFOX VIII chip that was introduced 11 years ago with Pentax's very first digital SLR, the *ist D. The 645Z is only the second DSLR from Pentax not to use a variation on the SAFOX VIII layout.

SAFOX 11 provides much better autofocus granularity, thanks to an increase in the number of autofocus points to 27. Of these, the 25 central points in a 5x5 array are all cross-types, sensitive to detail in both the horizontal and vertical axes.

Only two points, located in the vertical center at far left and right of the array, are linear points sensitive only on one axis. The centermost sensor as well as the points directly above and below it are precision points, capable of focusing with an f/2.8 aperture.

In contrast, the 645D had an 11-point, SAFOX VIII-derived AF sensor, dubbed SAFOX IX+. That provided only 11 AF points, nine of them cross-types, and lacks any f/2.8 precision points. SAFOX 11 also functions better in low light, with a working range of -3 to +18EV, where SAFOX IX+ bottomed out at -1EV.

Autofocus controls. Just as it did in the K-3, Ricoh has rejigged the Pentax 645Z's autofocus controls, probably because of the added complexity of the new 27-point AF system. While it will take a little getting used to for 645D shooters, it will quickly become second nature. The Focus Mode dial sits just where it did, a little to the left of the viewfinder, and still selects either AF-S (single-servo) or AF-C (continuous-servo).

The corresponding dial on the right side of the viewfinder is no longer used to control AF point selection, however. Instead, you now use the AF area button on the top deck, located where the SD2 button used to be. And as in the K-3, you have quite a few more choices. As well as the default 27-point auto selection, you can opt for Spot, Select, Expanded Area (Small, Medium, or Large), and Zone Select modes.

One further control is also new, located just below and to the left of the four-way controller on the rear panel. The Change AF Point button selects whether the Four-way Controller should be used to adjust the AF point location, or should abide by the markings on its buttons.

Why all the extra points? You might wonder why, exactly, do you need all these new autofocus points? If you're not shooting on a tripod, you can just reframe and focus with one of the existing points, after all. Not so fast, though... If focus is critical, that technique could subtly shift it -- and with the possibility of more abbreviated depth of field that medium-format allows coupled with the high resolution of the 645Z, it's more likely to be an issue with this camera than most. For that reason, you'll do better to use a focus point as near to your subject as possible, minimizing any shift.

And with AF tracking, the extra points can also pay dividends, albeit perhaps not quite as often as in a more sports-oriented camera. Still, the more points you have, the easier it is for the camera to accurately track distance as your subject moves across the image frame. And that's where the tie-in with the RGB metering sensor comes in, as well. Since it can now provide color information -- and a whole lot finer detail -- to the camera, it can be used to help track the subject's location, and determine whether or not a given autofocus point is over the subject. In other words, we can expect quite a step forwards in tracking autofocus performance.

Of course, you can focus manually as well. And here, too, there's a decided improvement. You can now shoot in live view mode, and as in the K-3, there's a focus peaking display -- so if you find fine manual focus adjustment tricky, you're more likely to get focus right where you want it. (With that said, the 645D's viewfinder was already an uncommon joy for manual focus, and given it retains the same viewfinder, that will be true of the Pentax 645Z as well.)

Viewfinder. On a surprisingly short list of features held over from the original Pentax 645D, you'll find the 645Z's through-the-lens optical viewfinder. If you're a fan of optical viewfinders, you'll feel right at home here: It's big, it's bright, and it's a joy to focus through. It also has a fairly generous 21mm eye relief from the view window, or 24.1mm from the center of the lens.

For the optics geeks amongst us, it's a Keplerian telescopic trapezoid prism finder, a design that allows Pentax to keep size to a minimum. It has 98% coverage, so isn't quite as accurate as the finder in Pentax's APS-C cameras, but by medium-format standards it's pretty good. Magnification is 0.62x with a 55mm f/2.8 lens at infinity; note that you can't directly compare this figure against a full-frame or crop-sensor camera, however.

Like its predecessor, the Pentax 645Z offers a dioptric adjustment range of -3.5 to +2.0 m-1, so eyeglass wearers with eyesight within that range are well catered for. If you need a little help, a magnifier eyepiece is optionally available, and you can also switch the bundled Natural-Bright-Matte focusing screen for a AF Framed Matte, Golden Section Matte or Cross-Lined Matte screen should you desire.

Also, if you want to preview depth of field, you can do so either through the viewfinder or by letting the camera capture and display a preview image using Pentax's intuitive Aperture position on the Power dial, just as in the company's crop-sensor SLRs.

Larger, better LCD. The most obvious physical change on the Pentax 645Z, as compared to its predecessor, is its new rear-panel LCD monitor. This, too, is inherited from the Pentax K-3. It has a slightly greater 3.2-inch diagonal, and a 3:2 aspect ratio. Together, those changes translate to around a 9% increase in surface area, and resolution has simultaneously been increased by around 13%. The total dot count is now around 1037k, up from 921k in the earlier flagships. The increase in resolution more than offsets the larger surface area, so perceived resolution is much the same as it was.

The 645Z's LCD monitor has a gapless design, as introduced on the K-5 II and IIs, and retains the anti-reflective coating of earlier models. Compared to the air-gapped design used in the 645D, it has lower glare and better contrast. The brightness and color adjustments of that camera have also been supplemented with a new saturation adjustment, letting you tweak yet another variable to your own tastes.

Articulated LCD. As you've doubtless noticed, a lot of the changes in the Pentax 645Z are inherited from the K-3. This one, though, is unique in Pentax's lineup -- an articulated LCD monitor. It's a tilting screen, rather than our beloved, side-mounted tilt / swivel design, but it's still a lot more versatile than a fixed-position screen. And frankly, it's pretty impressive that Ricoh has been able to add articulation in a camera that's weatherproof, dustproof and freezeproof. We don't currently have any figures for tilt range, but do know that the screen allows for framing low to the ground, waist-level shooting, or shooting over a crowd.

Live View. Of course, an articulated LCD wouldn't be terribly useful without live view capability. For those of you who are skimming for key features, though, we'll call attention to this again. It's a big change from the viewfinder-only framing of the 645D, and one that's only possible because of the 645Z's new CMOS image sensor.

Movie capture. This is another huge change for the Pentax 645Z: It is, to the best of our knowledge, the first medium-format camera ever to allow Full HD movie capture. (That is to say, 1,920 x 1,080 pixels.) No crop is applied; instead, video is recorded across the whole sensor, providing the same depth-of-field effects and medium-format look of still imaging.

You have a choice of interlaced 60 / 50 fields-per-second or progressive-scan 30 / 25 / 24 frames per second capture, matching the most-commonly requested formats, and movies are saved with MPEG-4 AVC / H.264 compression in a .MOV container. A lower-resolution 720p (HD; 1,280 x 720 pixel) mode is also available, and this replaces the two interlaced framerates of Full HD with progressive-scan 60 / 50 fps options.

Sound is recorded using a built-in stereo microphone whose two ports straddle the sides of the viewfinder housing, and you can also opt for an external microphone courtesy of a 3.5mm input jack on the left side of the camera body. The Pentax 645Z includes a levels control function which lets you tweak levels manually based on an on-screen levels display, but sadly there's no headphone jack for levels monitoring. The camera can, of course, also control levels automatically.

4K interval movies. As well as the aforementioned high-definition movies, the Pentax 645Z can also shoot 4K interval movies, a feature inherited from the Pentax K-3. These movies are saved using MotionJPEG compression in an AVI container, and they don't include sound. They have a resolution of 3,840 x 2,160 pixels.

Info LCD. The huge monochrome info display on the top deck is similar to that of the earlier camera, but has been rearranged a little to reflect changes on the camera body, and to better show information about the dual flash card slots and the file types used for each. It still has a green backlight, which can be illuminated with a dedicated button at its rear right corner.

Exposure modes. The Pentax 645Z, as you might expect for a camera aimed at pros and enthusiasts, offers the de rigeur selection of Program, Aperture-priority, Shutter-priority and Manual exposure modes. If you're new to Pentax, though, you may find the terminology used to describe the priority modes on the dial to be a little unfamiliar, and several other modes to be a mystery. Shutter-priority and Aperture-priority are, in Pentax parlance, known as Tv and Av respectively -- Time value, and Aperture value. There are also Sv (effectively, Sensitivity priority) and TAv (Shutter-and-Aperture priority) modes. In Sv mode, you select a sensitivity, and the camera determines the combination of shutter speed and aperture by itself. TAv is the exact opposite -- you decide the shutter speed and aperture, and the camera attains the metered exposure using only sensitivity adjustment.

As well as these modes, you also get a Bulb mode for long exposures, an X-sync mode that fixes shutter speed at the camera's flash sync speed of 1/125 second, and three User modes that allow you to save any of the camera's settings in groups for quick recall.

Wondering where the Movie mode is? You'll find it accessed with a dedicated dial to the right of the viewfinder. And there are, of course, no hand-holding Scene modes. Nor do features like custom image modes or digital filters merit a Mode dial position. This is not a camera aimed at consumers, after all.

Drive modes. Although its performance won't rival an APS-C or full-frame camera, the Pentax 645Z is unusually swift by medium-format camera standards. You'll attain the maximum burst performance of three frames per second in Continuous High mode, and a Continuous Low mode offers a reduced speed of one frame per second. Burst depths are 30 JPEG, 10 raw or 12 TIFF frames in the Continuous High mode, and 300 JPEG, 25 raw or 15 TIFF frames in Continuous Low.

There's also a 2 or 12-second self-timer function, and a remote control mode with an optional 3-second delay or continuous operation. And if you're feeling creative, you'll find both interval and interval composite drive modes on offer, as well as a multiple exposure mode. Both allow up to 2,000 frames, with an interval of two seconds to 24 hours, or a choice of additive, average, or bright compositing in multiple exposure mode.

Shutter speeds. Like the Pentax 645D before it, the 645Z offers a range of shutter speeds from 1/4,000 to 30 seconds in 1/3 or 1/2EV steps, as well as a bulb mode for longer exposures. (No limit is stated in bulb mode.) Exposures are timed with an electronically-controlled vertical-run focal plane shutter.

Longer-life shutter. Before we move on from the exposure system, this is probably as good a place as any to note an improvement that could see your investment in the 645Z -- a professional camera which commands a professional pricetag -- spread out over a significantly longer period. Where the original 645D had a manufacturer-rated shutter life of some 50,000 frames, the Pentax 645Z's shutter mechanism is rated as capable of attaining around 100,000 frames in its lifetime. (And Ricoh notes that this figure has been attained with the shutter being tested in the camera body, not on a workbench.) With twice as many shots available from the shutter, you should hopefully be able to get twice as many images out of your 645Z -- and therefore pay about half as much per image over the life of the camera.

White balance. There's one other piece of the Pentax 645Z's exposure setup that's seen some improvement: There's now a Multi Auto white balance mode, as seen previously in the K-3. This aims to neutralize color casts from multiple different light sources in the same scene, and again works in concert with information from that 86,000-pixel metering sensor. It's an adoption from Pentax's new parent, Ricoh, whose cameras have had the feature for a while now under another name: Multi-P Auto.

As well as Automatic and Manual modes, the Pentax 645Z provides ten white balance presets (Daylight, Shade, Cloudy, Daylight Color Fluorescent, Daylight White Fluorescent, Cool White Fluorescent, Warm White Fluorescent, Tungsten, Flash, and Color Temperature Enhancement). This last option is used to retain and enhance the lighting tone -- for example, to enhance a sunset.

Also worth note is that, as with its predecessor, the Pentax 645Z doesn't just rely on its CMOS imager sensor and clever algorithms to determine color temperature. There's a dedicated light source detection sensor whose information is also taken into account.

Creative options. Although you might not associate a pro-grade camera with things like digital filters, the Pentax 645Z nonetheless contains several, inherited from the company's consumer SLR line. (And why not -- after all, it likely cost little to nothing for Pentax to port them over from its existing firmware, given that the K-3 shares the exact same processor.) Instagram-friendly options like toy camera and miniature effect, not surprisingly, didn't make the cut. Filters you can use on the 645Z include Monochrome, Extract Color, Color, Base Tweaking, and Soft Mode.

You can also shoot high dynamic range images, assembled in-camera from multiple, sequential exposures. The Pentax 645D offered the same function, but the 645Z extends it with automatic alignment allowing handheld shooting, and with more blending options to choose from.

And of course, the 645Z retains Pentax's Custom Image modes function, with presets including Bright, Natural, Portrait, Landscape, Vibrant, Muted, and Reversal Film. Each of the color modes provides a gamut radar, and allows the photographer to tune saturation, hue, high/low key, contrast, regular or fine sharpness. In Monochrome mode, you can apply filter effects (green, yellow, orange, red, magenta, blue, cyan, or infrared), toning (sepia warm/cool), high/low key, contrast, and regular or fine sharpness to your liking.

Flash. As you'd expect from a camera aimed at pros and deep-pocketed enthusiasts, there's no built-in flash strobe in the 645Z. Instead, medium-format strobists will be relying on external strobes and studio lighting when ambient light doesn't suffice. (But thanks to the high-sensitivity sensor, that should be the case a lot less often than before.)

The Pentax 645Z has an x-sync speed of 1/125 second, and strobes with high-speed sync will function at reduced power to 1/4,000 second. The camera includes both a P-TTL-compatible hot shoe and an X-sync socket. A dedicated X-sync position is included on the Mode dial, as well. Wireless flash is possible via an external strobe mounted on the hot shoe.

Level gauge. Just like its predecessor, the Pentax 645Z includes a dual-axis level gauge. You can view both axes on the rear-panel LCD monitor courtesy of a display somewhat reminiscent of an aircraft attitude indicator, and the side-to-side roll axis can also be confirmed through the viewfinder's status display. You can also opt for a more minimal display on the main LCD, allowing you to view framing at the same time.

Copyright tagging. Also held over from the 645D is the ability to optionally embed copyright data into the Pentax 645Z's raw or JPEG image files. You can enter both a photographer and copyright holder name from the camera body, and the headers of images will be tagged with both. It's not a permanent tag, and so you can't rely on it to protect your images from copyright theft, but it does make it so that you can easily identify who shot a particular image in your library.

Playback. The Pentax 645Z's slightly larger LCD monitor provides more space in which to review your images, and its playback-mode features have been adjusted appropriately. You can now view 1, 6, 12, 20, 35, or 80 images on-screen at once, and the playback zoom function provides everything up to a 16x enlargement. There's also a 1:1 display where each on-screen pixel corresponds to an image pixel, a function that was added in the Pentax K-3, and a quick zoom function is available.

As well as allowing you to apply digital filters to images post-capture, the Pentax 645Z also lets you develop raw files in-camera. Developed raw can be saved as JPEG or TIFF files, and you can adjust resolution, compression, color space, and many more settings prior to developing the raw file, just as you could in the 645D.

Storage. Like its predecessor, the Pentax 645Z has dual Secure Digital card slots. However, they're now compatible with higher-speed UHS-I cards, not just the higher-capacity SDHC and SDXC types. You have a few choices as to how the card slots can operate: Either mirroring each other with all data saved to both cards, sequentially with one card being used when the other is full, or segmenting by file type, with raw images on one card and JPEG on the other. You can also copy data between the two card slots manually.

Wi-Fi. While the 645Z lacks in-camera Wi-Fi support, if you'd like wireless connectivity, you can opt either for Eye-Fi cards, or for the Pentax-badged variant of Trek 2000's Flucard. The latter allows not just data transfer, but also remote control, including a live-view feed and support for aperture, shutter speed, ISO, focus point, and shutter release control.

Connectivity. Ricoh has also upgraded the connectivity options of the Pentax 645Z, just as it did previously with the K-3. The new 645-series flagship is among the rare few cameras featuring a USB 3.0 SuperSpeed data connection, which Ricoh says is three times faster than the USB 2.0 High-Speed connection of earlier models. It's located under a flap on the left side of the camera body.

Alongside it sit a Type-D Micro HDMI high-definition video output, a 3.5mm stereo microphone jack, a DC input. On the same side of the camera is a flash x-sync socket, while a hot shoe sits on the top deck, and a wired remote control terminal on the right side. As well ass the wired remote, the Pentax 645Z also works with infrared remotes, courtesy of dual receivers on its front and rear panels.

Note that the HDMI port does not allow an uncompressed live view feed.

GPS. Although the 645Z doesn't offer built-in GPS functionality, it is compatible with Pentax's hot-shoe mounted O-GPS1 accessory. This offers the ability to geotag your images with information about the capture location, including capture direction from an electronic compass. It can also be used to automatically correct the camera's internal clock. Since it doesn't have a sensor-shift stabilization system, the 645Z also doesn't support Pentax's clever Astrotracer function, which allows some models to freeze star motion during long exposures, preventing star trails from forming. Nor does it support the simple navigation function.

Power. The Pentax 645Z draws power from a proprietary D-LI90 lithium-ion battery pack, the same type used in the 645D, as well as all of the company's flagship DSLRs since the K-7, and its K-01 mirrorless camera. In the 645Z, this pack is capable of 650 shots on a charge, down from 800 shots in the original 645D. (That, at least in part, will be due to the greater processing requirements of the newer, higher-resolution camera.) Playback time is 400 minutes, down from 440 minutes in the 645D. No figure was available for movie recording life at press time.

Software. Ricoh includes an S-SW150 software CD-ROM in the package with the 645Z. This includes the Silkypix-based Digital Camera Utility 5, a utility for editing raw and JPEG files shot with the camera.

A separate utility called Image Transmitter 2 will be available soon. Much like the existing Image Transmitter software for the 645D, this allows you to shoot remotely and transfer images via a tether cable to your computer. However, you can also now view a remote live view feed, and change settings remotely.

Accessories. Quite a range of accessories will be available for the Pentax 645Z, many of them also compatible with the earlier model. Sadly, there's no portrait grip accessory, but you can select from a wide range of lenses, adapters and extension tubes, flash strobes, the O-GPS1 GPS receiver, Eye-Fi and Flucard SD cards, viewfinder eyepieces and attachments, focusing screens, wired and wireless remote controls, and more.