In the Photography world, 35mm, or "full frame" is the standard by which nearly all cameras are judged. Focal lengths, crop factors and other camera traits are all based on the 35mm equivalent. Granted, a 35mm digital camera sensor is the largest sensor available in the consumer circuit, thanks to models like the Canon EOS 5D Mark II and Nikon D800. But what would happen if we transcended a 35mm sensor—a chip even bigger than the ones found in flagship full frame models like the Nikon D4 and Canon EOS D1x? Welcome to the land of Medium Format photography, my friends.

Medium format cameras have been around since the late 1800's, going down in history as the giant, boxy accordion cameras used to capture portraits of your great grandparents. These monsters of the photographic persuasion used a film larger than 35mm, the most popular sizes being 6×4.5cm (645), 6x6cm (66) or 6x7cm (67). Using larger film produced higher quality images, since the negatives did not need to be enlarged as much as 35mm film. Today, Medium Format DSLRs specialize in sensors (around 40MP) that are even bigger than 35mm chips found in top-of-the-line DSLRs.

A few manufacturers make Medium Format DSLRs at present, though they're not as popular as 35mm DSLRs. One reason is the price. A Hasselblad Medium Format DSLR can cost anywhere between $14,000 – $44,000. Mamiya makes less expensive Medium Format DSLRs, but they're still in the $10,000-$18,000 price range. Pentax is the first consumer-oriented manufacturer to make a Medium Format DSLR, and the 645D is $10,000 for the body only.

Medium Format cameras are also unwieldy in size. The Pentax 645D is about twice the size of a larger DSLR. In addition, it requires a fair amount of photographic skill to get the most out of a Medium Format DSLR, which is only appealing to pros and advanced hobbyists with money to burn. However, with the right pilot behind the lens, the benefits of Medium Format shooting can be monumental. Let's take a ride with the Pentax 645D.

The Wooly Mammoth of Digital Photography


Pentax 645D vs. the Olympus E-PM1

The Pentax 645D is a colossal beast of a camera. Take a two Canon EOS 60D bodies, superglue them together, and that's the general size of the 645D. It was too big to fit in any of my camera bags, so I had to rely on a backpack to haul the anvil around. The Pentax 645D is also a scale crusher. By the end of a handheld shoot, your arm will need to be replaced with a bionic one. This thing is so massive that it has an extra tripod mount on its left side for vertical stabilization.

Aside from its cumbersome size, the Pentax 645D was not that difficult to shoot with. The camera had plenty of real estate for external controls, including five dials, 19 buttons and a four-way directional pad. Since the Pentax 645D captures such large image files, it's equipped with a dual SD card slot. The camera also has a Mini HDMI terminal, hot shoe and X-Sync socket for synchronizing a flash.

Similar to a higher-end full frame DSLR, the Pentax 645D has a 3-inch 921,000-pixel LCD monitor in back paired with an optical viewfinder with 98% magnification and a nice, wide eyecup. There's also a secondary digital LCD on top of the 645D that can be illuminated via the press of a button. Pentax shipped me a Pentax-D 55mm F2.8 SDM AW prime lens to shoot with, and I was quite impressed with the quality. The lens has a crop factor of 0.78x, so any focal length of a compatible lens will have to be multiplied by that number in order to reach the 35mm equivalent. Of course, lenses built for the 645D, like the one I was shipped, do not have crop factors.

Shooting with the Pentax 645D


Unsheathing a $12,000 camera in public is an unnerving experience. Every time I took the cinderblock out of my backpack I heard "Don't drop it!" playing on a broken record inside my mind. Buttons on the 645D are silent and they don't click—they just sink to the bottom of the camera's chassis until there's no more room in their chambers. As a result, it was difficult to auto focus at times since the shutter button did not have two steps. I had to guesstimate a mid-way press before burying the shutter button all the way down. The mirror would then open with a thundering clap before hammering back down on the massive sensor like a guillotine sent to slay 40 million pixels. The Pentax 645D was no point-and-shoot.

One imperative caveat regarding Medium Format cameras is their exceedingly shallow depth of field. Since the Pentax 645D's sensor was larger than a 35mm sensor, it was beyond simple to focus a subject in the foreground and blur the background completely. The lens's curved 9-blade aperture made lovely bokeh effects as a result. Of course, depth of field is dependent on the distance from the photographer to the subject, so the 645D also did a fantastic job shooting landscape photography as well. If you're looking for unusually shallow depths of field to play with, a medium format camera is a prime tool to use.

Depth of field:

Pentax-645D-DOF-2Pentax-645D-DOF-1As far as camera controls, the Pentax 645D was fairly basic. The camera had a 200-1,000 ISO range that was expandable to 100 and 1600 at both ends. There was a 30-second Shutter Speed with Bulb mode, advanced White Balance Kelvin grid adjustment and 77-segment Auto Focus system. Of course, the Pentax 645D did not have a video mode, which nestled the camera even further into an exclusive niche.

Pentax 645D Image Quality

Pentax-645D-LeftThis is the department of the review where this monster shines. The Pentax 645D is equipped with a 44x33mm 40-megapixel CCD sensor. To place the giant's sensor in perspective, let's compare it to a standard 36x24mm full frame sensor found in cameras like the Nikon D700 and Canon EOS 5D Mark II. Although the Pentax 645D is not stocked with one of the larger medium format sensors, it's still a significant leap from full frame.

Color depth and tonality from the Pentax 645D were fantastic. Detail was electric, down to the last pixel. The camera's high ISO performance was quite impressive, as general low light sensitivity was not a major issue for the 645D. However, the Pentax 645D definitely requires an adept hand. Any shooting scenarios that contain dynamic lighting will usually end up darker than expected. The 645D has Shadow and Highlight Correction functions, but their effectiveness is limited in heavily contrasted shooting environments. As a result, I had to either shoot in Manual and heed the digital light meter or play with the Exposure Compensation. The best solution with a medium format camera is to watch your lighting in general.

The difference between RAW quality and JPEG quality on a medium format camera like the Pentax 645D is substantial, and that's a characteristic of the larger sensor. The 645D's RAW images exhibited brighter exposures, finer detail and more natural colors. If you're going to shoot seriously with the Pentax 645D, you must shoot in RAW, no exceptions!

The images below were captured in a pitch black setting at a long exposure. The first image is the JPEG while the second image is the RAW touched up slightly in Adobe Lightroom.

Pentax-645D-Shed-JPEGPentax-645D-Shed-LightroomUnfortunately, I detected some purple fringing along highlighted edges in some environments, which is most likely attributed to the 645D's lens. One would hope! Unfortunately I could not try any additional lenses on the 645D to test this hypothesis, but the effects present in the images were textbook chromatic aberrations, and that's unacceptable in this price range. Fortunately this was not a common occurrence, and was present mainly in defocused portions of the frame.

Again, the depth-of-field was so shallow at close range that only a slice of the image would be in focus at wide open apertures. The benefit of having such a large sensor was that images could be shot from farther away to achieve a greater depth-of-field, and then cropped in post without much of a loss in image quality. The Pentax 645D records RAW and JPEG images. The average RAW file size is 65MB while the average JPEG file is 16MB. Those are prodigious file sizes for the average photographer, and I was required to size the sample images down before uploading them to the gallery.

All image samples in the gallery were captured in RAW at full 40-megapixel resolution, then processed into high-quality JPEGs using Adobe Lightroom. The image of the Kawasaki and the Playground were touched up a bit in Lightroom. For the sake of bandwidth, the images had to be sized down slightly, but you can see them in their largest form by clicking on them from the gallery.

The Buffalo Call

Pentax-645D-LeftIt's no secret that the Pentax 645D will only appeal to a miniscule percentage of photographers. Professionals who are looking for magazine-quality portraits, landscape sharks who want an Ansel Adams edge and eccentric shooters who long for the days of oversized film will be the prime candidates for this camera. Its depth-of-field is sinfully shallow, allowing shooters to use focus to their advantage. Its image quality, especially in RAW, is on par with the top full frame gladiators. External controls are bountiful, making quick adjustments easy.

Yes, the Pentax 645D is an unwieldy monster. It's not portable and you'll have to find an extra large camera bag. Your arms may fall off after a full day of shooting, but there's nothing like the sound of that guillotine mirror descending upon that giant sensor, slaying all 40 megapixels in one fell swoop. Yes, it's no Hasselblad. But if you're in the market for a medium format camera and are looking for an alternative to Leica and Mamiya, the Pentax 645D should not be overlooked.

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