Pentax 645D

Pentax 645D

Pentax’s 645D is a digital day version of their popular 645 series of medium format film cameras. It uses the same lens mount as the film versions and so is compatible with all of the old manual, or autofocus lenses used by the film bodies. Surprisingly, it took 5 long years to develop. I was lucky enough recently to find out if those five years have been worth the wait.

First Impressions

Undeniably, it’s hard not to notice the sheer size of the 645D. It has the same basic design and size of the film versions of the 645’s, albeit a little bulkier and – that is to say – big. Very big. Build quality wise, simply put: it is a tank. It is solid, heavy and would faithfully stand up to years of abuse without a hiccup. If you’re a seasoned Pentax shooter, despite the 645 being a very different standard of camera to anything else that Pentax make, you will feel very much at home with the 645. The menu system and layout are typical of a modern day Pentax (which is to say: simple, intuitive and easy to use). The only difference you will find with the controls is that (whereas with a conventional Pentax DSLR, where a single button has several functions), the 645D has a lot of buttons to control various individual functions and nothing else. Each button serves only one purpose which means that there are a lot of buttons to become acquainted with, but once they have all been memorised, it allows for much faster usage. Also, each button is extremely large and easy to press when pressing is intended (accidental pressing is not an issue, despite their size); making fiddling for small buttons a nonexistent problem.

One of the features that is impossible to ignore is the control LCD screen on top of the camera. It is massive. Really… you can’t believe just how massive it is. It is almost on par with the size of a conventional DSLR’s normal image viewing LCD screen, found on the back of a camera. But this LCD screen is purely for changing the parameters of the set up and nothing else. There is still the LCD screen for viewing images and negotiating the menu system on the back of the camera, as would be expected. That is of a typical 3 inch size. But the status LCD screen is not far behind in size. In fact, it measures roughly the same width as the main screen and is about 2/3rds of the height of the main LCD screen… it’s that big! Needless to say, it displays a wealth of information from the usual shutter speed, aperture value and ISO settings and much, much more; to even the set up for each individual SD card. I could write a short article just explaining how much info the control LCD screen displays. It was a pleasure using such a comprehensive control screen that was so easy to use and to read with its large sized type.

Another defining factor about a camera as big as the 645 is that with a big sensor comes a big mirror. And big mirrors cause a lot of vibrations while shooting. This is typical of medium format cameras and is not something that can be completely eradicated. But it can be reduced. One of the most prominent buttons on the camera body is the Mirror Up function. And it is a button that will be used extensively. The mirror is large enough that small earth tremors are felt when shooting, which makes attaining sharp images very difficult to do at slow shutter speeds, when hand held. Medium format cameras generally struggle in low light/available light situations as their high ISO performance is quite lacking and so shooting at slow shutter speeds is often unavoidable with cameras such as the 645D. When you experience the mirror shake, it will instantly become understandable as to why they’ve made the Mirror Up switch so large and prominent.

Ergonomics-wise, the 645D is reassuring and a pleasure to hold, despite its size and weight. The indent in the hand grip where your fingers would be situated is extremely deep and so your hand really does feel like it completely encompasses the handgrip, which prevents any accidental dropping of the camera (which would normally be easy, considering its weight).

Unlike many other medium format cameras, the 645D doesn’t have an interchangeable back and so can’t be upgraded to higher resolution backs (not that one really needs more than 40 megapixels – in my opinion – because if you’re the kind of person who believes 40 million pixels isn’t enough, chances are that no number will ever be enough), but the benefit of not having an interchangeable back is that the body is typical of high end Pentax bodies in that it is completely weather sealed.


In Use

Unlike full frame cameras which all have the same 36x24mm dimensions, not all medium format cameras conform to the same formula. Some are 6×7, or square format 6×6. The 645D is named after the format that its film generation models were based on which is 6×4.5cm, although the 645D doesn’t have a sensor of those exact dimensions. It is actually 44x33mm. It may be the smallest of the medium formats, but it is still 1.7x larger than 35mm full frame and it shows in the images. For those that understand how a larger format can have more potential for having shallower depth of field with the right lenses, the 645D is no exception and would make a fashion photographer very happy as the images it produces are outstanding in that regard.

Other areas in which the Pentax shines are, understandably, resolution and sharpness. The sharpness and detail are particularly exceptional and – honestly – there’s not much more that can be said on the subject. It’s phenomenal. That’s all there is to it. Also impressive is the autofocus. Speed wise, it won’t win any autofocus speed awards but that’s not to say that it isn’t sufficiently quick. In fact, it’s not really much noticeably slower than a mid range DLSR. It’s hardly a camera that one would use for shooting sports, so most users won’t be too disappointed by its autofocus. But what was particularly impressive to me is how accurate the autofocus is. I couldn’t help but notice that it was spot on every time. Even the best autofocus systems get it wrong every now and then, but not with the 645D. Considering how shallow the depth of field was with the lens I was using, any out of place focusing would have been noticed instantly and the 645D exhibited not even a small amount of either back or front focusing in any shot, even accidentally. This is particularly important, considering that most medium format cameras don’t have the most sophisticated autofocus; especially when compared with commercial DSLR’s. In terms of speed, other areas of the camera are a lot slower. Particularly with regards to frame rate. At full speed, it shoots 1.1 frames a second and that’s largely because the file sizes are, well, large and require a lot of processing. It is typically the down side to extremely high resolution cameras. It is standard for medium format. Again, it won’t be used by sports photographers and so a frame rate any faster than that is simply not needed on a camera like this.

The 645D has twin SD card slots. Many would criticize the choice of using SD cards in a camera of this caliber and not Compact Flash. But that was an issue a few years ago when SD cards were achingly slow in comparison to CF. Modern day SD cards are much faster and in fact aren’t far off from the fastest speed CF cards. Using a top class SD card in the 645D is more than up to the task and the time taken from capture to writing images and reviewing them after a shot is really no time at all. A benefit of using SD cards is that – despite having two card slots – the camera needn’t get any bigger (which is a good thing considering that it is already hefty in size). Another benefit is that high speed SD cards are much cheaper than high speed CF cards and – considering how quickly this camera eats up memory cards – you’ll be glad that it uses the cheaper of the two when you inevitably have to buy many high capacity cards.

In terms of high ISO grain, the 645D performs respectfully, considering how high the resolution is and that medium format cameras tend to be quite bad at anything but the lowest of ISO’s. But those who are used to the stratospherically high ISO’s that modern day DSLRs are capable of will find the 645D very restrictive. The highest ISO of which the Pentax is capable is a modest 1600 ISO, with no option of expanding any higher. This is because – as is normal with medium format – the sensor is a CCD design and not CMOS. The reason for this is that medium format cameras are designed to be used under controlled lighting situations, i.e. in a studio with powerful lighting, at low ISO’s. And despite the old technology, CCD sensors do perform better at low ISO’s than CMOS sensors do. It is only at higher ISO’s that CMOS shows any benefits. And it shows. 100 and 200 are beautifully clear. 400 ISO starts showing small amounts of grain, but it is not very noticeable yet. 800 ISO starts becoming more apparent. From here onwards, you would only use ISO settings that high in natural light. 1600 ISO shows high amounts of grain, although it is not bad in quality. Visible grain need not be bad grain and the 645D has a pleasant quality about it. And also keep in mind that because the sensor has such a high megapixel count, if you resize the image down to more conventional dimensions, you will effectively be shrinking the grain in the image to the point where it is hardly noticeable anymore, while still maintaining more than enough resolution for most print purposes. So with careful usage, the 645D is even easily usable at 1600 ISO, which may not be high when compared with even an entry level camera available these days, but it is very good by medium format standards.



The Pentax 645D is a beast of a camera that is built like it could withstand wars. Overall, it is large, but not overly so when looking at medium format cameras as a whole. That size does have the benefit of having an almost limitless level of control, with more buttons than many will know what to do with. The control LCD screen is nothing short of gargantuan and is actually a pleasure to use. With the large size comes an extremely large and bright viewfinder. But with that large viewfinder comes a massive mirror; capable of alerting emergency authorities to the possibility of an earthquake, just from the small tremors that the mirror shake creates. Thankfully, the mirror up button is large and situated in a prominent area as it will no doubt receive a lot of attention and usage. The Autofocus speed is responsive enough, but – importantly – error proof with its accuracy. Image quality is phenomenal both in terms of detail and sharpness and, with the right know how, is capable of being used throughout its limited ISO range. Over the years that the 645 format has been in use by Pentax, they have developed quite a comprehensive and brilliant system of lenses, with more being developed every year. And with an adapter, one could even use Pentax’s even bigger lenses on the 645D from the Monster of all SLRs: the Pentax 67. At the price of $9 000.00 (yes, that is meant to read dollars), the 645D would probably give most photographers shooting with lesser systems a small heart attack. But considering that most medium format cameras that have as much of an extensive system available to them can cost almost twice as much, the Pentax 645D is actually great value for money. It would make a perfect choice for someone who is shooting with a full frame camera and is looking to make the next step up in the quality of their work. It was one of the cameras I was most disappointed to see go when my test period was over. Once you get used to the quality of medium format, it is hard to go back to anything else. So, was it worth the 5 year wait? I would be willing to wait longer.