DigitalCameraReview.com
Pentax K20D Review
by JerryJ -  3/14/2008

When Pentax announced the K10D back in 2006, serious amateurs and professionals quickly started paying attention. The K10D was more rugged and feature-packed than any Pentax digital SLR before it. In 2008, the company decided to update their line with the Pentax K20D, featuring a stabilized 14.6 megapixel CMOS image sensor, high quality image processing, dust- and weather-proof seals, 11-point AF, and more custom features than any photographer would need.

Pentax K20D
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If you're in the market for a Canon EOS 40D or a Nikon D300, pay close attention. The Pentax K20D might just be the best choice you can make.


FEATURES OVERVIEW

Overall, the features and specs of the K20D are remarkably similar to the features and specs of the K10D. The most notable changes include the 14.6 megapixel CMOS image sensor which, in theory, produces a far superior signal-to-noise ratio over the lower-resolution CCD image sensors in Pentax's older cameras. In terms of continuous shooting performance, the K20D has the same 3 frames per second burst performance at maximum resolution found on its predecessor. Unfortunately, the K20D can no longer capture unlimited JPEGs at this speed and stops after 38 exposures. If you need to take continuous photos until the memory card is full, you will need to set the camera to capture burst images at a maximum speed of 2.3 frames per second.

On the other hand, the K20D does offer a fun 20fps shooting mode...but the resolution is limited to only 1.6 megapixels when shooting at this overwhelmingly fast burst speed. The following is a quick overview of the various shooting modes:

"Green" Mode

The K20D features a "Green" mode that Pentax describes as, "...an automatic point-and-shoot mode in which the majority of settings are controlled by the camera in response to shooting conditions." The camera will let you choose from a couple of flash options, image size and quality, ISO sensitivity, and AF/MF modes if you desire, but the camera handles the rest of the settings. If you're content to go with default settings, the K20D can come out of the box and the inexperienced shutterbug need never worry about anything other than composing and capturing images.

Of course, anyone foolish enough to purchase a camera like the K20D only to use it in "Green" mode deserves serious ridicule. Green mode does a pretty good job across a range of subjects, but the entire point of a DSLR is that it is not a point-and-shoot camera. DSLRs are for photographers who want to take control over their images.

P, Sv, Tv, Av, TAv, M, X-sync, B, and User

Finally, the camera also has the Program Auto, Sensitivity Priority (Sv), Shutter Priority (Tv), Aperture Priority (Av), Shutter and Aperture Priority (TAv) and Manual exposure modes that are the standard features (plus a few unique options) on any DSLR. In addition, the K20D also features a Bulb mode (B), which allows you to manually control how long the shutter remains open for extremely long exposures. The X-Sync mode automatically defaults to the standard flash sync speed for the K20D: 1/180 seconds. User mode is a custom mode that the photographer can preset to their favorite shooting mode and settings.

For a detailed listing of specs and features, check out the specs table at the bottom of this review.


FORM, FIT, AND FEEL

Styling and Build Quality

The K20D is a slightly chunky very traditional looking DSLR that is virtually identical to the K10D.

Pentax K20D
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As a semi-pro body, the K20D is larger and heavier than entry level DSLRs, and the K20D is one of the heaviest cameras in its class.

Pentax K20D
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The K20D uses the same polycarbonate body shell seen in the K10D over a metal alloy frame with stainless steel lens mount and heavy duty dust/weather seals should stand up to anything short of armed conflict.

Pentax K20D
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The built-in handgrip and its rubber-like covering provide a very secure hold and a stable balance point (for right handed shooters).

Ergonomics and Interface

Like all Pentax K digitals, controls are logical, well placed, and quickly become intuitive.

Pentax K20D
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The Fn button (direct access to Sensitivity, Flash, White Balance, and Drive Mode settings), Exposure Compensation button, dedicated RAW button, and twin control dials are well placed and easily accessed.

Display/Viewfinder

The K20D monitor is a 2.7 inch LCD with 230,000 dots and adjustable brightness levels. The monitor itself is a "wide view" type with a viewing angle of more than 140 degrees both vertically and horizontally. You can easily show images to multiple people using the camera's monitor, and images can be magnified up to 12x magnification. The monitor also includes a "Live View" mode which allows you to compose shots with the LCD (more on that later).

Pentax K20D
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The K20D has a bright and reasonably large viewfinder with 0.95-times magnification and 95% accuracy – above average for cameras in this price range.


PERFORMANCE

As one would expect from the successor to the popular K10D, the K20D proved to be a solid photographic tool with respectable performance across a broad range of areas.

Timing and Shutter Lag

The K20D was designed to be the closest thing in Pentax's current lineup to a "pro body" and its fast startup and short shutter lag times reinforce that position. It takes a mere 2.1 seconds for the camera to turn on, shake dust off the sensor, find focus, and take a photo. That level of speed rivals camera bodies that cost considerably more than the K20D. Measured shutter lag with the camera pre-focused clocked in at .04 seconds – more than respectable, if not as fast as the top pro bodies. With the updated 18-55mm kit lens, the K20D averaged .28 seconds to lock and fire without pre-focus.

Auto Focus

The K20D uses an advanced 11-point auto focus mechanism, and the user can also select the focus area for automatic or manual focus. In addition to the AF.S/AF.C/MF switch located next to the lens mount, you can also make fine adjustments to AF using the AF adjustment menu option. The two auto focus mode choices are single mode (AF.S) or continuous mode (AF.C). AF.S is for stationary objects and locks focus when the shutter is depressed halfway; AF.C is primarily for moving objects and focuses continuously while the shutter button is depressed halfway.

Unlike many DSLRs, with multi-point auto focus systems that use only one or two cross-type sensors (capable of detecting both vertical and horizontal focus), the SAFOX VIII auto focus system on the K20D uses nine cross-type sensors, meaning greater auto focus accuracy.

The K20D acquired focus quickly across the range of auto focus lenses I shot with it (18-55mm, 70-210mm, 24-70mm, 50mm, and 200mm). The AF sensor also recognized when a manual focus lens was correctly focused, though it relies on the photographer to turn the lens' focus mechanism. The K20D is clearly one of the fastest bodies in the Pentax lineup, but it was hard to recognize any clear auto focus speed improvement over the K10D. That said, the K20D auto focus was slightly quieter.

While we're on the subject of auto focus speed, let's talk about the "Live View" function mentioned earlier. Live View allows you to use the LCD to compose your image rather than use the camera's viewfinder. On the surface this sounds like a great feature for consumers who are moving from point-and-shoot cameras or photographers with poor eyesight. Unfortunately, the Live View mode on the K20D isn't as good as it sounds.

You have to press the AF button located on the back of the camera to activate auto focus while in Live Mode, and this causes the viewfinder mirror to flip down (temporarily ending Live Mode and making the LCD go black). During this black out period it is impossible to track subject motion and keep your subject in the frame. Once the mirror flips back up you can compose your photo again, but if your subject is moving your image is now out of focus again.

In short, the Live View mode works fine for composing shots of stationary subjects that don't move. However, if you need to photograph a moving subject you will need to use the regular viewfinder. Live Mode is almost useless for action.

Flash

A built-in flash pops up from the top of the camera body when you press the flash release button located on the left side of the camera. The built-in flash range is between 0.7m and 4m depending on ISO/aperture settings.

Up to four flash modes are available with the manual shooting modes: auto, manual, auto with red-eye reduction, and manual with red-eye reduction.

The only negative issue with regards to flash is that the maximum flash sync speed is only 1/180th of a second. While this is fine for flash photography in low light, daylight fill flash often requires shutter speeds of 1/500th or faster. In order to use the flash in strong daylight I often had to use apertures of f/22 or more – not ideal.

Of course, if you purchase a Pentax hot shoe flash such as the AF360FGZ ($299) or the AF540FGZ ($399) flash units, you can use the high-speed sync mode for daylight fill flash at faster shutter speeds. It's just unfortunate that consumers have to spend an additional $300 for daylight fill flash. It shouldn't be that way.

One nice addition to the K20D was the inclusion of a standard X-sync socket on the left side of the camera. Now it's easier than ever for studio photographers to connect strobes directly to the camera without the need for hot shoe adapters.

Image Stabilization

One of the key points to remember about the K20D is that it is fully compatible with every Pentax lens ever produced. There is no other camera manufacturer that can make the same claim. What is even more amazing is that thanks to the camera's built-in shake reduction system every lens benefits from modern image stabilization technology. While the merits of in-body image stabilization versus Canon/Nikon's lens-based stabilization have and continue to be debated, the hefty premium paid for stabilized lenses makes the in-body system that much more appealing. With Pentax, even a 40-year-old lens has 21st-century shake reduction. Bottom line: your images will look sharper than ever.

Battery

The battery compartment on the K20D is in the base of the hand grip behind a weather-proofed twisting release tab. Unlike the release tab on the K10D, the tabs on the K20D are longer and wider which makes it easier to open the battery compartment when you're in a rush.

Pentax K20D
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The battery used in the K20D is the same D-LI50 Lithium-Ion rechargeable which is rated as having a capacity of 1620 mAh at 7.4V (12 Wh), which translates into about 500 exposures. The D-BG2 optional battery grip is the same one used on the K10D and allows for the use of a second battery for twice the battery life. Just like the camera, the grip is also weather proof for added durability.


IMAGE QUALITY

As with most DSLRs, image quality depends in part on the image sensor and in part on lens quality. Pentax has long been respected as one of the finest lens manufacturers in the world of camera optics so the K20D suffered little due to the glass mounted to it. Default settings on the K20D all of the sample images were taken with default sharpness levels and even the in-camera JPEGs produced perfectly acceptable results that rival any camera in this price range.

Pentax K20D
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It's worth mentioning that Pentax includes the new DA 18-55mm AL II lens (which was used for our studio shots) if you purchase the "kit" version of the K20D. This rebuild of the popular DA 18-55mm lens offers a new lens construction which provides better edge definition and contrast over the older 18-55mm lens. The Pentax website says, "This lens has improved resolution to match with high resolution sensors and PENTAX SP coating which protects the exposed lens elements." We didn't conduct detailed laboratory testing of the new lens, but I can say this particular lens seems to perform better than my personal copy of the older DA 18-55mm lens. A cropped foliage shot from the edge of the image shows the most striking area of difference:

Pentax K20D
DA 18-55mm AL II

Pentax K20D
DA 18-55mm

 

Exposure, Processing, and Color

Default metering on the K20D is Pentax's 16-segment multi-pattern metering system, with center-weighted and spot options also available. Multi-pattern metering on the K20D did a reasonably good job overall, but it did lose highlights on occasion with very bright, high contrast scenes, such as bright skies or water shots where sunlight reflecting off the water appears pure white. That said, these conditions produce similar results among other digital cameras from other manufacturers. High contrast scenes with more consistent light levels produced better results.

There are several optional image tones available in the K20D: Bright, Natural, Portrait, Landscape, Vibrant, and Monochrome. Bright is the "default" setting for the camera straight out of the box. My experience with both the Pentax K10D, K100D Super, and Pentax *ist DL has been that the Bright setting actually produces oversaturated colors and sometimes leads to overexposure and "graininess" in images. However, the K20D seems to perform well with the default Bright setting and so this was the setting used for most of the sample images in this review. Below are test photos taken with the various color tones:

Pentax K20D
Bright (default setting) (view large image)
Pentax K20D
Natural (view large image)
Pentax K20D
Portrait (view large image)
Pentax K20D
Vibrant (view large image)
Pentax K20D
Landscape (view large image)
Pentax K20D
Monochrome (view large image)

 

The K20D is capable of using either the sRGB or Adobe RGB color spaces. Although the Adobe RGB color space offers more choices in terms of color range for retouching, sRGB should be used by most amateurs as it will produce much more vivid colors both on screen and in print.

All shots by the K20D used in this review were shot in the default sRGB mode color space unless otherwise stated. The default space provides deeply saturated colors and seems particularly strong in the reds and greens. It reminds me of slide film in terms of needing to deliberately underexpose images with strong reds and greens if you want to saturate those colors without over-saturating them. In fact, I often used a -0.3EV exposure compensation when shooting bright colors with the K20D.

The menu system on the K20D also allows you to adjust saturation, sharpness, and contrast in order to produce your ideal image straight out of the camera. All of the sample images in this review use the default settings for saturation, sharpness and contrast.

White Balance

Overall, auto white balance on the K20D (like all Pentax DSLRs) tends to favor warmer color temperatures and looks a bit yellow straight out of the camera. This tends to work fine for landscapes and portraits but it can be a little frustrating if you prefer your images to have a cool or neutral color temperature.

Manual white balance and other preset white balance options look to be spot-on in terms of color accuracy. Of course, if you prefer to take absolute control over your white balance you can manually adjust the color temperature using the in-camera menu to fine tune the white balance exactly where you want it.

Sensitivity and Noise

In terms of image tone and noise, the K20D is a reasonably solid performer.

Pentax K20D
ISO 100
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Pentax K20D
ISO 200
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Pentax K20D
ISO 400 (view large image)
Pentax K20D
ISO 800 (view large image)
Pentax K20D
ISO 1600 (view large image)
Pentax K20D
ISO 3200 (view large image)
Pentax K20D
ISO 6400 (view large image)
 

 

Pentax K20D
ISO 100

Pentax K20D
ISO 200

Pentax K20D
ISO 400

Pentax K20D
ISO 800

Pentax K20D
ISO 1600

Pentax K20D
ISO 3200

Pentax K20D
ISO 6400

 

 

ISO 100 to 400 are free of serious noise/grain. ISO 800 starts to show some noticeable noise when viewed at 100 percent magnification on screen, but ISO 1600 and 3200 are still perfectly useable. The K20D also includes a menu option to "Expand sensitivity" which increases the maximum ISO to 6400. While 6400 is very noisy, it still delivers usable images when you require extremely high ISO performance.

As the ISO increases with any camera, so does the noise. The problem with reducing ISO noise is that nose reduction usually causes some loss of detail. To combat the issue of noise and detail loss, Pentax included adjustable high sensitivity noise reduction on the K20D. The photographer can select "Off, Weakest, Weak, or Strong" for the noise reduction method. As the names suggest, "strong" noise reduction will attempt to remove as much noise as possible while sacrificing some image detail. The "weakest" setting will do some noise removal but will attempt to retain as much fine detail as possible.

While the K20D offers higher ISO settings (ISO 3200 and 6400) compared to the older K10D, our tests suggest there may be little in the way of real-world ISO noise improvement. We took a sample photo using the K10D set to ISO 800, underexposed the image by 2 stops and then push-processed the image in Photoshop by 2 stops to create the equivalent of an ISO 3200 image. We then took a similar image with the K20D set to ISO 3200.

Pentax K20D
K20D, ISO 3200 (view large image)
Pentax K20D
K10D, ISO 800 pushed 2 EV(view large image)

 

The resulting images are shown above, but our opinion is that there isn't much difference between ISO 3200 on the K20D and ISO 800 pushed to 3200 on the K10D.

Additional Sample Images

Pentax K20D
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Pentax K20D
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Pentax K20D
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Pentax K20D
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CONCLUSIONS

Since my day-to-day camera is a Pentax K10D, I was curious how the K20D would compare. I expected the camera to perform better than the K10D and prove to be a worthwhile upgrade. What I discovered was that the K20D is an amazing camera in much the same way as the older K10D. In short, while it's a very good camera, it might not be a worthwhile upgrade for current K10D owners.

Focus speed of the K20D is about the same as the K10D, just a little quieter. The 3 fps continuous shooting performance is nice, but the similarly speced Canon 40D and Nikon D300 have much faster continuous shooting performance. Also, the fact that you can no longer shoot JPEGs at 3fps until the card fills up was a disappointment.

Image quality is among the best I've seen in the sub $2,000 price range but the ISO noise was only marginally improved over the older K10D. The full compatibility with every Pentax lens means almost limitless options for expansion and growth of your photographic skills. Colors are rich even at the "natural" image tone setting. In-camera shake reduction and dust removal means that this mid-level camera is remarkably full-featured. Thanks to the intuitive control layout, any serious photographer will feel right at home.

Bottom line: if you don't already own a K10D, at the $1,299 (and lower) price point the K20D may be the best value on the market.

Pros:

Cons:

 

Pentax K20D Specifications:

Sensor14.6 megapixel, 23.4x15.6mm CMOS
Lens/ZoomPentax KAF2 mount; compatible with all K mount lenses
LCD/Viewfinder2.7", 230K-dot (76K-pixel) TFT LCD with Live View; Pentaprism optical viewfinder with diopter adjustment
SensitivityISO 100-6400
Shutter Speed30-1/4000 seconds
Shooting ModesGreen, Program, Sensitivity Priority, Shutter Priority, Aperture Priority, Shutter and Aperture Priority, Metered Manual, X Speed, Bulb, User
Scene PresetsN/A
White Balance SettingsAuto, Daylight, Shade, Cloudy, Tungsten, Fluorescent W, Fluorescent D, Fluorescent N, Flash, Color Temperature, Manual
Metering ModesMulti, Center-Weighted, Spot
Focus ModesAF Single, AF Continuous, Manual; Auto, User-Selected Point, Center
Drive ModesSingle, Continuous High, Continuous Low, Burst, Remote, Remote Continuous, Auto Bracket, Extended Bracket, Multi-Exposure, Interval
Flash ModesOn, Red-Eye, Slow Sync, Slow Sync + Red-Eye, Trailing Curtain Sync, Wireless
Self Timer Settings
10 seconds, 2 seconds, Off
Memory Formats SD, SDHC
Internal Memory
None
File FormatsJPEG, RAW (PEF/DNG)
Max. Image Size4672x3104
Max. Video Size
N/A
Zoom During Video N/A
BatteryRechargeable lithium-ion, 740 shots
ConnectionsUSB 2.0, video output, DC input, X-Sync socket, cable switch
Additional FeaturesShake Reduction, Live View, Custom Image Functions, Dust Reduction System