645Z Summary Medium-format cameras offer truly spectacular resolution, but until now, it's always come alongside a difficult compromise. With the Pentax 645Z, that changes. Building on 2010's 645D, the Pentax 645Z offers features that are rare or in some cases unique in a medium-format camera. Pick up its weather-sealed body, and you'll find both live view and video capture on offer, not to mention an extremely wide sensitivity range, 27-point phase-detect autofocus system -- and compared to rivals, very swift performance too! And of course, you'll get the incredible detail-gathering capability of medium-format, plus a really big, bright viewfinder. Is it time you considered moving up from full-frame? Read on and find out! Pros Phenomenal resolution and detail; Great high ISO performance; Rugged, weather-sealed body; Huge, bright viewfinder; Fast autofocus works well in low light; Swift performance for a medium-format camera; Good battery life; Shoots Full HD video Cons Quite bulky compared to an APS-C or full-frame DSLR; Autofocus points clustered near center of frame; Most lenses aren't weather-sealed or optimized for digital; Prone to aliasing artifacts (but so are most high-end cameras these days); Attracts a lot of attention from passers-by Price and availability Available since June 2014, the Pentax 645Z is priced at US$8,500 body-only. Imaging Resource rating 5.0 out of 5.0

Pentax 645Z Review

by Mike Tomkins

Preview posted: 04/14/2014

Updates:

08/20/14: First Shots posted!

08/21/14: Performance results posted!

09/02/14: Gallery sample photos posted!

09/11/14: Field Test Blog Part I: Ricoh's mighty medium-format takes on the mile-high city

10/08/14: Field Test Blog Part II: Straying outside of the medium-format comfort zone

10/09/14: Image Quality Comparison and Print Quality Analysis

10/27/14: Conclusion posted!

Back in early 2010, Pentax launched the 645D, a medium-format digital SLR that it had been developing for the previous five years. It might have been a long time coming, but it was nonetheless exciting for it. The 645D leapfrogged rivals Canon, Nikon and Sony with two-thirds greater sensor area than a full-frame sensor, yielding a unique look and shallower depth of field. At the same time, it was vastly more affordable than offerings from medium-format makers like Hasselblad and Phase One, yet rugged enough to be used in the field.

The reason Pentax -- since taken over by Ricoh -- could offer its camera at a more attractive price-point than other medium-format products was pretty simple. Much of the design work for the 645D could be shared with the company's mass market, APS-C DSLRs, where Hasselblad and Phase One -- neither of which sells consumer SLRs -- had to bear the entire cost of development solely with their medium format products.

While Pentax lacked (and indeed, still lacks) a full-frame DSLR, the 645D served both as an aspirational model for the enthusiasts to look up to, and as something genuinely different to attract pros for whom that resolution and medium-format look was more important than high-speed capture. And boy, did it ever offer a lot of resolution by 2010 standards. (In fact, it's only recently that we've started to see cameras with smaller sensors catching up.) When we first put the 645D in our lab, we were amazed to find that it picked up details we'd never even noticed in our test scenes -- details that we couldn't even see with our own eyes, until we pulled out a magnifying glass to confirm them.

Just like the medium-format film cameras in whose footsteps it followed, the 645D was never going to be a mass-market camera. Medium-format is an even smaller niche than it was in the film days, but the 645D was nonetheless a very important camera for the company, and its followup -- the Pentax 645Z -- is no less important.

Just like its predecessor, the Pentax 645Z shares much with Ricoh's flagship APS-C DSLRs -- and with four years of development having taken place on the APS-C front since the 645D was launched, there was no shortage of new features for it to inherit. But the most important feature of them all is at its very heart, a brand-new, Sony-sourced 51-megapixel CMOS image sensor. It's coupled to a PRIME III image processor, as first seen in the K-3, and the 645Z also inherits that camera's 27-point SAFOX 11 autofocus and 86,000 pixel RGB metering systems.

The 645Z's new image sensor allows a spectacularly wide sensitivity range, especially by medium-format camera standards, covering everything up to ISO 204,800 equivalent. It also provides both live view and Full HD movie capture capabilities, neither of which its predecessor was capable of. And performance has taken a big step forwards, at least compared to other medium-format cameras. This still isn't a sports shooter, but it'll shoot at almost triple the speed of the 645D. You'll also be able to review photos post-capture in less than half the time.

Nor do the improvements stop there. The Pentax 645Z sports a larger, tilting LCD panel with higher resolution, an improvement that's doubly useful given the new live view function. And its shutter life has been doubled to 100,000 shots, giving you a lot more photos across which to spread the cost of your camera purchase.

Pentax has also gifted its new medium-format camera with the K-3's support for high-speed USB 3.0 SuperSpeed transfer and UHS-I compatible Secure Digital cards, as well as the clever Pentax-badged (but rather unappealingly-named) Flucard, which allows remote live view and remote control via Wi-Fi. And like the K-3, you can also shoot 4K interval movies with the 645D. These won't include sound, but Full HD movies will capture stereo audio either with an onboard mic or an external one, complete with automatic or manual levels control. And the list of new features goes on, as you'll find out in our Technical Info section. Let's take a closer look at the 645Z.

Walkaround. Seen from the front, the Pentax 645Z looks a whole lot like its predecessor, the 645D. In fact, the most notable difference is the brand-new, silver badge on the front of the viewfinder prism housing, which used to be black. Look a little beyond the surface, though, and this is clearly a new body. It's grown in depth by a tenth of an inch (4mm) and in weight by 2.5 ounces (71g), neither of which will be noticeable in the real world. Like its predecessor, this isn't a small camera -- but it's also not as large as you might think it from the photos.

In terms of height and width, the Pentax 645Z differs little from typical full-frame cameras like the Canon EOS 5D Mark III or Nikon D800. It's actually a little bit narrower and a fair bit shorter than professional cameras like the Canon EOS 1D X or Nikon D4S, in large part because it doesn't have a portrait grip.

Where the 645Z loses out in the comparison is in its depth and weight. The medium-format sensor that pays dividends in other areas needs a much larger mirror box, so as to provide room for the reflex mirror to swing aside before each exposure. That extra depth -- around 1 to 1.5 inches more than the 1D X and D4S -- is greatest at the lens mount, rather than the hand grip, giving the 645Z a chunky, blocky aesthetic. Weight is about a quarter more than the D4S (and similar to that of the 1D X), at 54.7 ounces (1,550g) loaded and ready to go.

But that's a small price to pay for a sensor that's about two-third larger in terms of surface area than a 35mm full-frame sensor. And on the plus side, it also gives the Pentax 645Z plenty of room for external controls that have been designed for use even with gloved hands. That's something you'll appreciate if you take advantage of its freezeproof design. It's also weather-resistant and dustproof, with 76 seals throughout, just like its predecessor.

And there's little question that this is a pro-grade body, either. It has a die-cast aluminum chassis beneath a magnesium-alloy exterior shell -- not a hint of polycarbonate in sight.



Seen from above, there are a few differences between the Pentax 645Z and the earlier 645D. There are three new User modes on the Mode dial, replacing the single mode of the earlier camera and making it easy to access multiple settings groups that you've configured ahead of time. The line of buttons down the left side of the body have also been tweaked, with the SD buttons replaced by AF Area and Lock buttons, and the order changed to move the Bracketing Mode button forwards. There's also a new stereo microphone whose two ports straddle the sides of the viewfinder prism housing, and a two-hole speaker a little further back on the right side of the housing.

Moving to the rear of the 645Z, you'll find the majority of the changes -- and they've largely been made to accommodate the new LCD monitor. It's both larger at 3.2 inches in diagonal, and adds a tilting mechanism for viewing over the head, at waist-level, or low to the ground.

The row of buttons that previously sat beneath the display are gone, with their four functions assumed by the arrow buttons of the four-way controller. The same buttons are also used to adjust the autofocus point location, courtesy of the same AF point button seen previously in the Pentax K-3. (This control also doubles as the card selection button in playback mode.)

The column of buttons that used to line the right of the LCD, meanwhile, have become a square cluster at the base of the camera's right rear. One of these, the Delete button, also gets a second purpose as a Movie Record button when the camera is in Movie mode. And since AF point selection is now achieved elsewhere, the dial to the right of the viewfinder that previously served this function now acts as a dedicated Still / Movie control dial.

Looking at the left of the left side of the 645Z's body, the standard-definition composite video output has been removed, and in its place is a new 3.5mm stereo microphone jack. The remaining ports under the same rubber flap are much the same, although the USB port is now a USB 3.0 SuperSpeed type, and the arrangement of the ports has changed. Note that there are also still two Secure Digital card slots under the door that sits above the connectivity compartment, and these are now UHS-I card compatible.

And finally, we move to the right side of the camera body, where there's but one change of note. The wired remote control terminal, previously found under a flap on the rear of the body, now sits in the handgrip. It's a logical move, given the lack of space elsewhere. If you're shooting with a remote, you're not going to need to hold the grip, after all.

And that about does it for the Pentax 645Z's physical changes. Let's take a look at what's inside the camera!

Pentax 645Z Technical Insights New sensor, new processor, faster AF, video and more! 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.) Click to read about the Pentax 645Z technical insights!

Pentax 645Z Field Test Part I Ricoh's mighty medium-format takes on the mile-high city I've shot with many professional DSLRs over the years, right back to when even the most expensive of pro gear consisted of digital innards shoe-horned into a repurposed film SLR body, but there was one type of camera that I'd never managed to get my hands on -- at least, away from the trade show floor. Until now, I've never had the chance to shoot a medium format DSLR. The Pentax 645Z is a first for me, and it's one I've been greatly anticipating. I don't think it's too much of a spoiler to say that it's living up to my expectations. As I said on our news page when I posted my Pentax 645Z gallery a few days ago, this could never be considered a stealth camera. For a medium-format camera, it's actually reasonably compact, with similar width to a professional full-frame DSLR like the Canon 1D X or Nikon D3/D4-series, and since it lacks a portrait grip, it's significantly less tall than any of these. But with the best will in the world, there was little Ricoh could do to reduce its depth -- it has to fit in a medium-format mirror box, after all -- and so it's in this dimension that the Pentax 645Z stands out from other pro cameras. Depending on which of these pro cameras you choose to compare it to, the 645Z is about 30-50% deeper. How did I get on with my first medium-format experience while shooting in Colorado? Read Field Test Part I

Pentax 645Z Field Test Part II Straying outside of the medium-format comfort zone When I published part I of my Pentax 645Z Field Test a little before the Photokina tradeshow, I promised that another report was on the way that would look at Ricoh's mighty medium-format camera in more challenging conditions. After a manic stretch of camera announcements and news coverage for the show -- plus a little time to recuperate -- I'm finally back and fulfilling my promise. It's time to take this medium-format DSLR outside of the traditional comfort zone for medium-format cameras! And boy, did I ever have some fun shooting the 645Z at night in downtown Denver, my extremely patient wife serving as lens caddy while I carried the 645Z and a Feisol Traveler CT-3441S tripod all over town looking for interesting shots. I'd have liked to have had a sturdier tripod with me, but the Feisol was small and light enough to fit in my carry-on, yet rated for a reasonably generous 22 pounds, and actually did a pretty good job. What did I think of the Pentax 645Z after shooting in more challenging circumstances? Find out in Field Test Part II

Pentax 645Z Image Quality Unreal resolution and now higher ISO chops than its predecessor Below are crops comparing the Pentax 645Z with the Pentax 645D, Nikon D810 and Sony A7R. Given the massive 51.4MP, it's difficult to find competing cameras that match this resolution, however we've matched the new 645Z up against it's predecessor -- naturally -- and also the two latest, highest-resolution full-frame cameras currently available -- the Nikon D810 and Sony A7R, which have 36.3 and 36.4 megapixel resolutions, respectively. We've also decided to change up our typical IQ Comparison layout to offer larger crops -- the 250 x 250-pixel square crops normally seen in our IQ tables just don't show much with a 51.4MP image at 100%. NOTE: These images are best quality JPEGs straight out of the camera, at default settings including noise reduction and using the camera's actual base ISO (not extended ISO settings). All cameras in this comparison were shot with our very sharp reference lenses. Read our Image Quality Analysis on the 645Z

Pentax 645Z Print Quality Big sensor, big resolution, big prints As we've said on rare occasions with only a few other cameras that have come through our lab, your printer will love you for having a Pentax 645Z. Stunning images at ISO 100-400 are limited only by resolution, which in this case is absolutely astronomical.This is what you'd call "getting the job done" in the print quality department, and we weren't at all surprised by these results given how much we love the 645D. A solid upgrade, and well-done Pentax. Click to see just how well the 645Z did. *[Note to readers: we no longer rate sizes higher than 30 x 40 inches, as we felt this wasn't useful. At low ISO's, higher-end cameras are now virtually only limited by their resolution, and not by noise. The real achievement begins as ISO climbs to 800 and higher, so this is where we're concentrating our print quality analysis going forward.] Read about the Pentax 645Z Print Quality