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Pentax 645Z First Impressions Review

By Michael Reichmann
and Nick Devlin (@onelittlecamera)

It was 2005 when Pentax first announced that they would be building a medium format digital camera. Unless your memory stretches back to pre-digital days you may not know that Pentax was one of the major medium format camera makers, with several very popular 645 and 67 format camera over several decades. But unlike many camera makers who were sideswiped by the digital bus, Pentax hung in and in 2010 delivered the Pentax 645D. Nick had some initial comments and an interview with Bill Gouge of Pentax Canada in September 2010, and a more comprehensive review of the camera in November of that year.

Now it's mid-year in 2014, almost seven years on, and Pentax has just started to ship their next-generation Pentax 645Z. Though the "Z" looks a lot like the "D" a great deal has changed. Here then, for those who have not already memorized the product brochure, are the more salient points...

– 51.4 million pixels, 43.8 x 32.8mm large CMOS image sensor. This is the same Sony fabricated sensor as found in the Hasselblad H5D-50c and Phase One IQ250. 

– 3.2" articulated 1.3M dot LCD with Live View and a large prism 98% coverage optical viewfinder system.

– ISO range from 100 – 204,800

– 3 fps continuous shooting

– 27 autofocus points including 25 cross-type sensors

– 1920X1080 HD video 60i/30p/24p

– video capability

Even a cursory look at the major specs shows that the most significant new feature is the use of Sony's new CMOS 43.8 x 32.8mm sensor, now also used by Phase One and Hasselblad. This is the first medium format CMOS sensor and consequently brings heretofore unavailable features in MF, such as higher frame rates and high ISO, as well as proper Live View and video capability.

Of course just because cameras use the same sensor doesn't mean that they are the same when it comes to image quality. The entire imaging pipeline from the sensor onwards is proprietary to each maker and therefore small to moderate difference (maybe even major ones) are to be expected.

Before going further, let's just clarify that strictly speaking 43.8 x 32.8mm is not what was called medium format in the film days. It is some 63% smaller than 645 film, though it is 1.7X larger than full frame 135mm format.

Got it? Does this really matter? It is what it is, and comparisons to film formats aren't really relevant. Just keep in mind though that this format has a .8X factor when it comes to calculating lens coverage. That's about the only thing that should be noted. Keep in mind as well that this is the same size as the sensor in the Leica S, and we don't hear too many people complaining about that.


User Interface

Next, let's consider the user interface and user experience of working with the 645Z.

The chart above is there not to strain your eyesight, but rather to give you an impression of the strongest first impression that the 645Z gives – that is of their being a single dedicated external control for virtually every major and most minor functions. Whereas the smaller a camera gets the more controls have to be placed onto menus and custom functions, with a large camera such as the 645Z there is physical space to be allocated so that direct control is available.

Depending on your age and experience in photography this may be seen as either a good thing, or a bad thing. Lovers of simplicity (the Leica S approach) will likely find the 645Z to be confusing and even intimidating. On the other hand, a photographer who wants to have every control at his or her fingertips, will consider the new Pentax to be just the ticket.

That said, we found a hard-to-quantify but nonetheless palpable 'thickening' of the control interface from the previous 645D.  While there are only a couple more buttons, a number of the core controls lacked the transparency and fluidity of the original camera.  It may be that over a period of time this will disappear for experienced users, but Pentax did over do it a bit here.  The 'Green' button on the back is a prime example.  It is a shamelessly modal control, and badly out of place on a camera where virtually every control is first-order obvious.  The presence of JPEG WB controls on the four-way controller is another fail and a hold-over from  the company's consumer APS-C cameras (Pentax is not alone in including ridiculous controls like this on the ubiquitous four-way).   Auto ISO is a particularly badly implemented control, and we mention that below.

But we have to put these relatively minor critiques in context:  the 645Z is light-years ahead of any other MF-class camera, and frankly better than just about all of the FF 35mm machines in user interface.  Using a Phase or Hassy body is pure agony after handling a "Z". Many of the controls are blessedly well done, such as the pop-up menu that appears when one hits "INFO" during image review, which displays thumbnails of the four review options (eg: with or with histo, 3-colour histo, etc), between which one can quickly scroll. 

The "Z" is still a great user's camera. 

One simple example: I (Nick) still can't get the H4D I use to marry mirror-lockup to self-timer.  And I have to reset all of this everytime I power-up. By contrast on the "Z", two touches on the controls puts you in 2-second self-timer to which mirror-lockup is automatically linked! It's almost like an actual photographer was involved in the design. Revolutionary.

White house on the Hill, Clearview, Ontario, July 2014
Pentax 645z, 120mm, 1/500th @ f8, ISO100

Focusing

One of the reasons Nick sold his 645D was that it had trouble focusing accurately at middle distances – a plague of MF cameras.  In our brief testing the "Z" performed far better in this regard, not only as predicted in Liveview, but using the camera's phase-detect TTL AF system as well.  Objects in the sub-infinity range – typical of landscape foregrounds – were tack sharp most of the time.  Liveview contrast detection AF also worked well, as expected. 

Focusing speed is fine. Not great, but fine.  The newer lenses are predictably much faster and more positive than the older film-era screw-drives lenses, which had a distinct tendency to hunt.  The worst offender was the 120mm macro, which may be because of its enhanced range and precision of focus.  While it displayed a lot of 'jiggy" AF behaviour, the results were ultimately excellent.  No one will be using these cameras for high-speed AF applications, so I just don't think this really matters. 

In short, focus is not an issue.  The only anomaly we did see was with the new 25mm lens, which produced some inexplicably mushy shots on a couple of occasions.  We didn't have the camera long enough to drill-down on this, so I will make no more comment than to say this particular lens probably requires more serious attention when focusing on distant objects which have little texture on such a wide lens.

Affordable Starter Home, Clearview, Ontario, July 2014
Pentax 645z, 25mm, 1/125th @f8, ISO 100

Live View

Live view with an articulated screen is a real pleasure with MF.  The screen is better than either of its competitors simply because it can be brought to an appropriate angle no matter the position of the camera.  Live View works. We are all used to it now, so there's not much more to say.  Landscape photographers will enjoy this development a lot.

WIFI operation

We should mention the camera's WIFI capability here as a subset of Live View.  Although WIFI is not built in, one can add it for a few dollars by purchasing the oddly named "FLU" SD card.  One can then establish a browser-based link to the camera.  As with the other Pentax SLRs, this gives full camera control from the linked device, including touch-focusable Live View control.  Working off an iPad, this functionality operated well.  I could see composing and focusing on an iPad, almost like a hand-held ground glass.  How much better and/or more usable this is than the other ways of seeing with the camera would depend on the user and take some time to know, but it's nice to see this functionality on the "Z".

Tethering

The "Z" sports a USB3 plug.  Cabled tethering is coming in the fall, we are told.  This is a must-have for commercial pros, and I really, really hope Pentax gets it right. The announcement of true tethering is kind of a big deal, as Pentax made no effort to achieve this on the 645D, and thus cut-out a vast segment from its pool of potential customers.  Its inclusion on this camera shows a real commitment to making a competitive system.

Image Quality

So this is the real money-question: is the IQ up to snuff and worth the money?  The short answer is yes.  The files off the "Z" are superb.  Nick attempted some apples-to-oranges comparisons with the H4D-60, which were limited by the different ISOs, sensor sizes and focal lengths available to us.  However, when matched like-for-like as closely as possible, the "Z" produced files which closely rivalled the larger 60MP CCD chip.  That said, Nick could see what felt like a greater subtly of micro-contrast and colour subtlety on the Hassy files, which were challenging to reproduce on the "Z".  With a lot of playing in post, however, the difference in files came down to a matter of taste, and a small one at that.  If pushed, Nick would say that the Hassy file, at base ISO 50, was a bit more robust.  Simply put, nothing can (yet) beat a big CCD at optimal operating conditions.

An attempt at a studio portrait yielded a further interesting, in unintended, result.  The files from the Hassy produced unmatched skin tone. No real surprise there.  But the "Z" wasn't that far off.  In particular, the level of detail on both, and the smoothness of skin tonality, was mutually impressive.  Then the kicker....in trying to use to FLU card to send jpeg previews to an iPad as an experiment, we had accidentally set the camera to only shoot small, lowest quality jpegs.  Oops.

Thinking Deep Thoughts
Pentax 645Z, 55mm, f8, ISO100

Here's the kicker......the 21MP, 'lowest' quality jpegs were, on-screen, just amazing.  Converted to B&W, and tweaked quite a bit in LR, they are gorgeous.  This is not surprising, really, since a 20MP MF back was the state-of-the-art not that long ago.  And guess what – a file of this size is still pretty darn excellent, and fully up-to-par for almost any professional application.  (Of course, this fact has a lot of implications, which we address further down.)

The quality of the JPG produced in-camera is significant.  We had no time to test this, but the "Z" clearly produces a terrific file through its on-board processing.  I have no idea how the camera down-samples to 21 from 50MPs, but it's doing something right.  Pros in a lot of the "Z"'s target markets (we're looking at you, wedding folk) might find this a tremendously useful capability, shooting RAWs on one card and jpegs on the other. Potent.

Really knowing how good the 50MP CMOS sensor is, compared to its larger CCD brethren, would require a lot of lengthy, detailed work.  Our basic impression, however, is that the "Z" produces beautiful results that no one will be disappointed by.  How 'robust' the files are in aggressive post-processing is a question we would like more time to answer, but any differences vis-a-vis the rest of the field will not be that large.

All of this comes in the context of a camera with amazing high ISO capabilities.  CCDs simply cannot compete on that front at all.  Bottom line is superb IQ.  

Shutter-Shake

One of the other factors that led Nick to sell the 645D was a nagging sense that first-curtain shutter vibrations were degrading shots taken even on the heaviest tripod.  Pentax seems to have done something about this.  The shutter no longer produces the guillotine-like impact on opening that marred its predecessor.  We also saw no evidence of degraded IQ at the 'high-risk' shutter speeds.  In fact, the barn at sunset shot (below) was taken with the camera braced on a fence-post.  If the shutter were still a problem, this shot should have shown it.

Kudos to Pentax for having fixed this problem. 

Sunset Moonrise - Clearview, Ontario, July, 2014
Pentax 645Z, 55mm, 0.3s @f8, ISO 100

Other Use Issues

The "Z" has 35mm SLR genes, and it shows, in a good way.  The battery is a bog-standard $25 model. In addition to being cheap and plentiful, it runs forever, compared to its $250 brethren on the competitor's MF cameras.  Nice.  One can also buy a Pentax IR remote for next to nothing, along with an economical GPS module.  Nice. 

More importantly, perhaps, the camera feels good in the hand.  It's big, but it fits.  And it's weather sealed. Bit of sand? Just hose it off.  While we think it's foolish, people have done this and posted videos on the web.  Only the new lenses are weather-sealed, but this kind of protection on a field camera of this value is wonderful.  I would never hesitate to take this camera out, anywhere, whereas I worry every time the Hassy leaves the bag. 

The "Z" is a real working pro's field camera in every sense.  It's a camera that's almost never annoying to use, and will no doubt be a trusty companion for years of use.  I suspect the people who buy them will grow to love them.

The Use-Proposition

So here's the rub. Five years ago, the "Z" would have been a photographer's wildest fantasy.  An MF camera with world-leading high ISO, and live view, all under $10K.  Why then did it induce a bit of a shrug in both of us? The answer has a couple of facets.  First, the camera is big.  Coupled with a brace of lenses, this system is a serious commitment to carry around.  In photography, mass=hassle.  There is simply a high physical price to pay to use this kind of gear.

Second, the field has filled-in from below in stunning fashion.  Not long ago, nothing could rival MF backs, notwithstanding their usability deficits.  That's all changed.  The Nikon D800e/810 produces very similar results at a third the price, with a much broader range of high-quality lenses available, also at a  lower price.  More recently, the Sony A7r puts similar IQ into a camera the size of a cigarette pack.  And for the traveller-type, the Fuji X and Olympus Micro 4/3rds systems offer terrific IQ in pint-sized packages. 

Remember the accidental 21MP jpeg? An Oly OM-D-E-1M-D-M-E-whatever produces a gorgeous 16MP file.  Not all that much of a difference in the vast majority of applications. 

Put simply, who really needs a run-'n-gun MF camera?  The high ISO is amazing, yes.  The file is huge, yes.  The usability is on par with 35mm FF, yes.  But it costs a lot and is big and heavy. So why? Moreover, any erosion in the discipline required for maximum IQ (tripod, stopped down, etc) will have some impact on the quality derived from the machine.  With the quality of the vastly cheaper next-step-down nipping at MF's heals, it's not clear who will find it worthwhile.

The real problem with this camera, ironically, is that it is so usable that it invites the sort of run-'n-gun work that will inevitably degrade IQ, despite its enjoyability and convenience.  So you can very quickly find yourself with a file that has little advantage over one from an A7r....

For the past few months, Nick has had the use of a top-end Hassy camera.  It's like using a 486 computer, has no weather sealing, is an anvil to carry, and there's no point moving it off ISO 50.  But when all the rigour and discipline needed to max-out IQ is applied, the results are awesome.  BUT! The Hassy is unusable unless used slowly, and properly, in the right conditions.  I get no crappy images from it, because under sub-optimal circumstances, I wouldn't bother using it.  Ironic, no? The fact it's hard to use makes me a better user.  And I'm actually not sure I want to move away from that paradigm.  I'd prefer the 645z's usability and durability for sure.  But in work-style, I like what the Hassy makes me do.  If I need or want speed and convenience, I use a smaller system.

Michael, on the other hand, has been working with the 36MP Sony A7r of the past 6 months plus, and is more than happy with its image quality, especially when using a few of the Sony/Zeiss FE lenses. If medium format shooting technique is used...large, heavy tripod and precision head, careful focusing, etc, the files produced by the Sony leave little to be desired, even on exhibition quality 22X30" prints. DxO's ranking puts the A7r almost at the top of all current cameras, and with good reason. We don't know how the 645Z will rank yet, likely quite high, but then there's the issue of price.

Pricing

The Pentax 645Z sells in the U.S. for $8,500. The Leica S is $21,950, though it's a fair bet that this camera's sensor will be upgraded around the time of Photokina. (Do not expect it to use the same Sony sensor). The Hasselblad H5D-50c retails for $27,500, while the Phase One IQ250 back with a 645DF body will set you back about $40,000. Lenses are, of course, additional, and most medium format lenses, other than used, are quite expensive in their own right.

The question that one might well ask is; how can there be such a price spread between cameras that are using the same sensor. Good one. And one that I won't even attempt to answer. 

 

Nick Devlin & Pentax 645Z. Outstanding in His Field – AKA, a Corny Shot

But while the 645Z wins the price war handily at the high end, its erstwhile competitors from below really put the pressure on. The Nikon D800e/810 and Sony A7/r offer exceptional image quality in the $3300 and $2300 range. Want a large heavy DSLR, Nikon's got it. Want a small light mirrorless system camera, Sony's got it.

Michael's side-by-side comparisons with between the 645Z and the A7r show the Pentax to have about one school grade advantage over the Sony, but then only on-screen at 100% or in large exhibition sized prints. The difference is there, but so is the price differential at over $5000, and the weight and bulk differential are certainly not inconsiderable either.

Michael's take is that just a couple of years ago the 645Z would have generated want bumps, but now, hardly at all.

Clickety Clack and Wow

Nick and Michael sit on opposite sides of the fence when it comes EVFs. Michael has been shooting with mirrorless cameras for about two years now, and has lost interest in bulky DSLRs. Nick has never seen an EVF he's ever liked. One thing is clear. The 645Z has a very nice, bright and large optical viewfinder, though the Hassy still has an edge in this regard. It also has a large articulated LCD for Live View, with all the necessary accoutrement's, like focus peaking, highlight warning, level indicator and so sorth. In other words a totally modern design with a foot in both the old world and the new.

One thing that the 645Z shares with DSLRS is the clickety clack of the shutter, closing, opening, closing and opening again when in Live View. Oh yes, and the shutter similarly. Clickety clack.

Same Random Notes

Let's start with some praise. Pentax has its own proprietary raw format, but also allows the user to record raw in DNG format. Bravo Pentax. If only other manufacturers had the smarts and the balls to recognize that propriatry raw formats are not in their customers best interest. In fact, they are an insult.

The lens situation needs to be discussed. The Pentax 645 mount has been around for decades, and Pentax 67 lens, also decades old, can also be fitted via an adaptor. Because these lenses have been popular and available widely there are many on the used market, sometimes at very attractive prices.

But, even when in excellent condition many of these lenses are from another era (remember film?), and the demands that were made on them are simply not the same as from a state-of-the-art sensor such as the Sony unit fitted in the 645Z. 

There are three new lenses, which are weather sealed, and which appear to be of excellent quality. But, they are also expensive, up there with lenses from other medium format makers. Pentax is rereleasing their older lenses at more reasonable prices, but we suggest that you check around to find out which ones might be up to a world-class sensor's demands. In our brief testing, the 120 macro clearly was, but the 33-55mm lost a touch of quality in the corners.  And with MF, loosing a touch of quality means you might as well have used 35mm.

Finally, there are no leaf shutter lenses. This may be an issue for those working with flash in brightly lit settings, where the inability to sync at high speeds might be an impediment.

Michael noted a few other small niggles. Pentax, along with some other makers hides the Format command in the menus. Why. This is a frequently used control. Don't put it as the third item down on Tool Menu #4. Don't worry Pentax. We're all grown-ups here. We won't abuse it if you put it front and center.

From a functional perspective, as Nick has pointed out, there is little to criticise once one becomes familiar with the bevy of controls and menu selections. But, the image preview takes about 3 seconds till it appears. Yes, we know it's a big file, but 3 seconds? Seems like an eternity sometimes.

Oh yes, the camera has video, and it has built-in mics, and an external mic input, but no headphone jack? What's with that?

Farmville, Clearview, Ontario, July 2014
Pentax 645Z, 120mm, 1/400, f16, ISO200

Auto ISO Foibles

We are not enamoured of the way Pentax has implemented Auto ISO selection. Whereas most manufacturers place Auto ISO at the top of the ISO selection scale, and then have a menu choice where one can set the Auto ISO range, Pentax has made it a separate setting from the regular ISO selection process.

To engage Auto ISO one must press the top panel ISO button, while simultaneously press the mysterious rear panel green. To disengage Auto ISO one holds the ISO button down while turning the rear control dial to the left. While once learned, this isn't that difficult, on the other hand it is a somewhat byzantine interface design, and simply illustrates a thickening of the control interface complexity over the more pleasing simplicity of the previous 645D.

ISO Noise Performance

 


Full Frame of Crops Below

We'll start this section with with a flat statement – The Pentax 645D may well have the best high ISO performance of any camera to date (including the Sony A7s), and with little doubt has the lowest noise high ISO performance of any medium format camera, including as best we can tell that of the Phase One and Hasselblads that use the same sensor. 

The 100% screen grabs below contain the ISO information for each shot.

 
 
 
ISO 200
 
 
 
 

 

Our observations are as follow...

ISO 100 – Totally clean at 100%

ISO 200 – Totally clean at 100%

ISO 400 – Almost totally clean at 100%

ISO 800 – Almost totally clean at 100%

ISO 1600 – Very clean

ISO 3200 – Very clean

ISO 6400 – Slight luminance texture. Only slight NR needed

ISO 12800 – Visible noise, but no NR needed for printing

ISO 25600 – Noise visible, but cleans up nicely

ISO 51200 – Noisy. Usable with some NR

ISO 102400 – Very noisy. Loss of black density. Usable in an emergency

ISO 204800 – Very noise. Not really of use practical use.

 

Video – Fail Big Time

The Pentax 645Z is the first medium format camera to offer video capability. This is due to the use of the new Sony CMOS sensor, though it's interesting that neither Hasselblad not Phase One choice to implement video capability in the cameras that they released.

We did not have enough time to do any serious video testing, but Michael was keen to see how it performed. Due to its high resolution sensor the camera would obviously have to use binning, line skipping or some other compression to reduce its huge image down to HD. But the very first test done was  a simple pan upward to show a slowly rotating ceiling fan, so see how rolling shutter would be handled.

The short clip above tells the tale. The image completely breaks apart as soon as the fan starts to fill the frame. We now know that this was caused by the camera's video stabilization being confused by the rapid motion.

If the SR mode has been turned off this would not have occured, but we didn't know that at the time.  But, with our limited time at that point we decided not to test the 645Z's video any further. It was only afterwards that we learned how important it is to have SR turned off when shooting on a tripod.

The Pentaz 645Z is available for purchase HERE

Conclusion

If you have the money, or the lenses, or simply a love for larger-format cameras, the 645z will not disappoint you.  It's a world-class image-maker in every regard, and the fullest realization of the dream of a 35mm quality MF camera. The handling and high ISO make it unique.  The performance issue of the 645D have largely been ameliorated.  What remains is the question of whether the price in mass and money is worth it.  That one can only answer for oneself.  

 

July, 2014
Michael Reichmann
and Nick Devlin 

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Concepts: Single-lens reflex camera, Camera, Film speed, Image sensor, Digital camera, Digital photography, Charge-coupled device, Active pixel sensor, medium format

Entities: Pentax, Sony, Hassy, Pentax Canada, Hasselblad, Nikon, Phase One, FF, digital camera, optical viewfinder, continuous shooting, User Interface, user interface., SD card., Michael Reichmann, Nick Devlin, WIFI, APS-C, CMOS

Tags: medium format, Pentax, camera, live view, medium format camera, Pentax 645Z, next-generation Pentax 645Z, high ISO, Auto ISO, Pentax 645D, MF camera, quality MF camera, run-'n-gun MF camera, sensor, Pentax Canada, new Pentax, field camera, CMOS sensor, Pentax SLRs, format CMOS sensor, video capability, Pentax IR, large camera, camera control, CMOS image sensor, high ISO capabilities., world-leading high ISO, MF-class camera, lenses, ISO range, medium format lenses, best high ISO, Sony CMOS sensor, Auto ISO range