Pentax announced a trio of new interchangeable lens cameras on Wednesday—two D-SLRs...
Pentax 645D Review
At close to $10,000, the Pentax 645D’s price tag might shock you, but this medium format digital camera produces superb images, and it’s a bargain compared with competing systems.
(4 out of 5)
- Superb image quality
- Weather-sealed body
- Dual tripod mounts
- Inexpensive when compared with other medium-format systems.
- Lacks Live View
- No CompactFlash support
- Slow to write files to memory card.
Depending on the type of photographer you are, the Pentax 645D ($9,999.95 direct, body only) could be a dream camera or it could be one that completely befuddles you. Event photographers can stop reading here, as the 40-megapixel camera isn’t a high ISO monster, can’t record video, and doesn’t fire off shots in rapid succession. But if you’re more of a slow shooter—whether it be studio portraits or landscapes—the weather-sealed 645D may be right up your alley. It represents a relatively inexpensive path into medium-format digital photography, as the similar Hasselblad H4D-40 will set you back $16,995, and the Leica S2 is priced even higher at $22,995. Sports and event shooters should turn their attention to our Editors’ Choice full-frame D-SLR, the Nikon D4 ($5,995, 4.5 stars), which can fire off rapid shots and capture images in even the most challenging light.
Design and Features
The 645D is big, and it’s styled unlike a typical D-SLR. It has a very deep handgrip, but it’s body seems squat thanks to a mirror box that extends out much further than a camera with a 35mm lens mount. The body measures 4.6 by 6.1 by 4.7 inches (HWD) and weighs in at a hefty 3 pounds, 4.2 ounces. Compare this with the Nikon D800 ($2,999.95, 4 stars), a 35mm full-frame D-SLR that measures 4.8 by 5.7 by 3.2 inches and weighs only 2 pounds. Because of its weight, Pentax opted to put two tripod mounts on the body—one for portrait and one for landscape orientation—as some tripod heads won’t be able to handle the camera’s mass when used in a sideways position.
If you aren’t familiar with what differentiates medium-format, full-frame, and APS-C, it’s all about sensor size. The Pentax 645D’s CCD sensor is 33 by 44mm in size, which is quite a bit larger than the 24 by 36mm sensor found on a full-frame camera like the Canon EOS 5D Mark III ($3,499, 4 stars), or the 18 by 24mm sensor found in a mainstream APS-C D-SLR like the Sony Alpha 77 ($1,999.99, 4.5 stars). Because you need to cover a large physical area with light, lenses have to be bigger, as does the mirror box.
The 645D is actually based on a lens system that captured images on 60-by-45mm frames of film, and can accept older lenses that were used with Pentax 645 film bodies. If you have the appropriate adapter, you can also mount lenses designed for the Pentax 6×7 system, capturing huge 60 by 70mm negatives on 120 or 220 format film. Aside from pure resolution, which is now available in smaller format cameras like the Nikon D800 , there are plenty of reasons to choose medium format for your work. The larger sensor creates a different relationship between focal length and field of view. The 55mm lens that is often paired with this camera is a true normal—its focal length matches the diagonal measurement of the sensor. The equivalent focal length on a 35mm sensor camera is 43mm. This changes the distance between you and your subject, assuming that you want to maintain the same field of view, altering perspective. The larger sensor also creates a shallower depth of field than the equivalent lens on a smaller format camera, which is desirable for portraits.
If your biceps are up to it, the 645D actually handles quite well as a handheld camera, although I’d recommend using a tripod when you can. Its control layout is excellent, and there are physical control buttons, dials, and switches for almost every common function. The mode dial lets you choose standard shooting modes, there’s a dedicated switch to toggle between Spot, Center Weighted, and Matrix metering, and another switch to set the focus point selection to either the center point, manual selection, or automatic operation. Because the camera’s mirror is quite large, the vibration it causes when it raises to take a shot can actually cause some vibration that can hurt image quality. If your shutter speed for a shot is low and you’re working on a tripod, you can utilize the Mirror Lockup feature—a toggle switch on the right side of the mirror box that causes the mirror to raise and stay raised when you first trip the shutter button. Hitting the shutter again takes the photo. If you really need to minimize vibrations, you can use this in conjunction with the Self Timer to get a rock solid shot.
Control buttons let you adjust the ISO, Exposure Compensation, Color Space, White Balance, Exposure Bracketing, and Drive Mode. There are also buttons to toggle between Raw and JPG shooting, and to select which of the two SD card slots is in use. Current shooting settings are displayed in the eye-level viewfinder, as well as on the large monochrome LCD that adorns the top of the camera—if you’re shooting in a dim environment, there’s a button you can press to illuminate that display as well.
There’s no Live View mode on the 645D—the camera’s CCD sensor technology prevents that functionality—but it didn’t stop Pentax from putting an excellent 3-inch 921k-dot display on the rear of the camera, directly below the viewfinder eyecup. You can use this to configure the camera via its text-based menu system, or to review photos. The excellent resolution makes it possible to confirm focus, which is important when working with such a large image sensor, as it is less forgiving of slight focus errors.
Landscape photographers should take special note of the camera’s weather sealing. Pentax designed the camera so that it could be used in inclement weather, as every port, button, and opening is sealed against the elements. When you couple this with a weather-sealed lens—there are two available at the moment—you have a camera that can shoot in a downpour, windstorm, or worse. With a little trepidation due to the replacement cost, I simulated a downpour in my kitchen sink and placed the 645D under the running water—it performed like a champ, as I was able to pick up and shoot the dripping wet camera immediately.
Performance and Conclusions
The 645D is not a camera that is designed to capture fast sports action or work in a rapid-fire photojournalistic environment. It actually starts and shoots fairly quickly—in about a second, and records a short 0.2-second shutter lag when focusing in good light. But focusing in dim light, or if the lens needs to traverse a longer distance to lock on, shutter lag can increase to 0.5-second. The camera shoots at about 1 frame per second, but if you’re shooting in Raw or Raw+JPG mode it can only keep that pace for 6 shots, with recovery time taking about 45 seconds wen using a SanDisk 95MBps memory card. Shooting JPG lets you rattle off 7 shots, but also increases the recovery time to 51 seconds. If you want a fast-shooting camera, look elsewhere. The Nikon D4 can shoot at 10 frames per second and keeps that pace up for dozens upon dozens of shots.
I used Imatest to check the sharpness of the Pentax D FA 645 55mm f/2.8 AL [IF] SDM AW lens ($1,199.95) that was provided along with the camera for review—the 645D is only sold as a body only, so you’ll need to purchase a lens separately. The camera omits an anti-alias filter, which improves pure resolution, but can introduce unwanted moiré patterns when photographing certain fabrics or patterns. Medium format cameras generally omit this filter, as do certain high-end 35mm cameras like the Nikon D800E ($3,299.95) and the Leica M9-P ($7,995, 4 stars).
Not surprisingly, this camera and lens combination did quite well on the Imatest sharpness test. At f/2.8 the lens records 2,312 lines per picture height, which is well in excess of the 1,800 lines required for a sharp image. Resolution increases bit by bit as you stop the lens down, topping out at 2,541 lines at f/11. It decreases by about 100 lines at f/16, which indicates that diffraction has robbed a bit of detail—still, that’s plenty sharp for those times when you need to maximize depth of field.
Imatest also measures noise, which can make photos appear grainy and rob detail at higher ISO settings. The 645D keeps noise below 1.5 percent through its top standard ISO of 1000, and only hits 1.6 percent when you increase it to the extended setting of ISO 1600. More impressive, the images at all ISO settings were excellent in terms of detail; there was no visible evidence of heavy-handed noise reduction from the out-of-camera JPGs. If you opt to shoot in the Raw DNG format, you can manage noise reduction on a shot-by-shot basis using software like Adobe Lightroom. Still, even though you can comfortably use this camera at all available ISO settings, it doesn’t go nearly as high as CMOS sensor cameras. The Canon 5D Mark III , which uses a 22-megapixel CMOS sensor, keeps JPG noise under control through ISO 12800, although it does start to lose some detail at ISO 6400.
There’s no video support, but the 645D does have a mini HDMI port so you can connect and review photos on an HDTV. It also has a standard PC Sync so you can connect to studio lights or an off-camera flash, a remote control port, and a mini USB port for computer connectivity. There are dual card slots, each supporting SD, SDHC, or SDXC cards. Pentax opted not to support CompactFlash with the camera, which can account for its recovery time after burst shooting—CF cards generally perform better than SD cards, even if they are rated at the same speed.
If you’re in the market for a medium-format digital camera, but don’t want to spend as much as you would on a mid-sized sedan, the Pentax 645D is a solid option. Although its in-production lens lineup is limited to two weather-sealed lenses, there are plenty of compatible lenses available on the used market at reasonable prices, many of them with autofocus capability. The weather-sealed design should appeal to landscape photographers who will do anything to get the perfect shot, and the image quality that the 645D delivers will not disappoint even the most demanding shooters. It’s not a good camera for sports or news gathering—our Editors’ Choice full-frame D-SLR, the fast-shooting Nikon D4, is the best bet there, but once you move past the 35mm format in terms of sensor size, you’ll find that shot-to-shot speed gives way to image quality.
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By Jim Fisher, PCMag