The K-5 is the most technically advanced Pentax DSLR ever, but does it deliver high-end quality and performance? We test it in the field, and in the lab.
- APS-C-format 16.3 MP CMOS sensor
- In-body (sensor-moving) Shake Reduction system
- ISO 80-12,800 up to a class-leading 51,200 in High Sensitivity mode
- Maximum burst rate of 7fps for JPEG+RAW capture
- Selectable 11-point autofocus
- 77-segment metering
- 3-inch, 921-000-dot LCD
- 1080p HD video at 25fps.
Price: Approximately $1,470 body only; $1,580 with 18-55mm weather-resistant kit lens (prices accurate as of January 1, 2011)
The Pentax K-5 is the most technically advanced DSLR ever offered by Pentax and, like its predecessor the K-7 it’s squarely aimed at serious enthusiasts and pros. Its features and specs are impressive, especially considering that its Adorama price is under $1,600 complete with standard (27-82mm equivalent) short zoom lens.
What sets the K-5 apart in not merely its sheer technical prowess, but its pro-caliber build quality, which rivals that of many of its more costly rivals. Built on a very solid but reasonably lightweight stainless steel chassis clad with sturdy magnesium alloy body covers, its 77 weather seals provide excellent dust and weather resistance, and it’s cold capable down to a claimed 14 decrees F. Its solid glass pentaprism provides a commendably bright, high-contrast 100% view at 0.92X magnification, and its overall balance and ergonomics are outstanding.
In the hands
When you first pick up the K-5 you immediately notice its solid feel, compact size, and the fact that it nestles in your hands exceptionally well. The right-hand grip is anatomically contoured and it’s surmounted by a slightly angled shutter release that’s perfectly positioned for smooth firing.
The on-off switch surrounding the release is conveniently placed and has a third spring-loaded position denoted with an iris diaphragm logo. To select it, press and hold the knurled tab on the switch to the right and the camera stops down to the set aperture—a clever new twist on the traditional aperture stop-down button that gives you a rough ides of the depth of field in the final shot when you look through the viewfinder.
Portrait of Jenae: Impromptu headshot of spirited subject demonstrates the K-5’s outstanding image quality at ISO 6400. 50-200mm f/4-5.6 Pentax WR lens is tack sharp wide open at f/4.5 and exhibits beautiful bokeh at this aperture (note out-of-focus background). Picture was taken at 87.5mm (131mm equivalent) focal length.
A Distinctive Array Of Modes
Other distinctive features that give the K-5 its unique personality are found on the mode dial atop the left side of the camera. In addition to the usual Green “auto everything,” Tv (shutter priority), Av (aperture priority) and M (manual mode) there’s the P (Hyper-program) auto-exposure mode that sets both aperture and shutter speed automatically but lets you change either variable the fly.
You change shutter speeds with a knurled wheel in the front of the shutter release and apertures with a similar control on the back of the camera to the right of the eyepiece. Both wheels or dials are ideally placed for easy manipulation with the forefinger and thumb respectively.
Sv mode is like the traditional P mode, setting aperture and shutter speed to provide the correct exposure at your selected ISO. TAv mode automatically sets the ISO to obtain a proper exposure at your set shutter speed—a useful alternative when action stopping is crucial. In M mode, you manually select both aperture and shutter speed, and the deviation from the correct exposure is displayed in +/-EV in 1/3-stop increments on the large top-mounted LCD.
The LCD screen also displays shutter speeds, apertures, ISO, battery condition and number of frames remaining on the SD card. It’s illuminated in a distinctive green color. B is the usual Bulb setting for time exposures, X locks the shutter speed at the 1/180 sec flash sync speed, the Movie Camera Icon mode is for shooting movies, and the USER mode lets you capture images with your saved exposure mode and allows you to store up to 5 settings.
Horsing around on skates: Athletic young couple at ice-skating rink was shot at 7fps in Hi Speed mode to test the K-5’s high-speed performance and AF tracking, which is very good indeed. Metering system set to multi-pattern mode also acquitted itself remarkably well in dim, heavily backlit interior. To freeze the action at 1/2000 sec we had to boost the ISO up to 6400. Data: 50-200mm Pentax WR f/4-5.6 lens, f/4.5 at 125mm (188mm equivalent) focal length.
Cruising through the K-5’s intuitive, easily-navigated menu settings reveals a number of useful pro-oriented capabilities. These include:
- Electronic on-off Lens Correction settings for linear distortion and lateral chromatic aberration adjustment;
- HDR capture for optimizing highlight and shadow detail with subjects having an extended brightness range
- Dynamic Range (DR) setting for optimizing shadows and/or highlights;
- A setting for displaying a built-in electronic level in the finder (useful when shooting landscapes and architecture);
- E-dial and button customization that lets you customize the functions of the exposure dials and camera controls individually for each exposure mode.
Scroll through to the Custom (C) menu and you’ll find a very useful item (number 26), AF Fine Adjustment, that allows you to fine tune the camera’s AF system to match the precise focusing characteristics of any lens. This is a feature found only on pro and prosumer DSLRs.
Also in the first of four “C” menus is Expanded Sensitivity, which allows you to set ISO sensitivity settings from 80 to 51200 for both RAW and JPEG images. And speaking of file types, there’s an ingenious little button just below the “flip flash open” button on the left-hand side of the camera labeled RAW that lets you shoot a RAW frame while in JPEG capture or vice versa if you hold the button in while taking the shot. Cool!
Fire escapade: The 18-55mm f/3.5-5.6 Pentax WR lens delivers excellent image quality wide open at 50mm and the sharpness and color saturation are superb at ISO 400. Picture was shot in A (aperture priority) mode.
Little touches make a difference
Little quality touches abound on the K-5. The furnished Pentax strap comes with little leather tabs that cover the attachment rings to prevent scratching the body. The battery cover opens and locks with a sturdy metal twist latch. The mode dial has a central lock button to prevent inadvertent settings.
The clearly-marked AF control provides settings for multi-zone AF (in 11- or 5-zone configuration via the menu selections), central spot AF, or SEL, which lets you manually select the AF zone in use. You also have three options for AF operation—AFS (single shot AF (which retains the initial focus setting when you shoot a sequence), C (continuous focusing option that’s ideal for shooting moving subjects), and provides focus tracking when used in conjunction with multi-zone AF. The final AF option is, of course, manual focus (MF).
I also liked the LV (Live View at any time) button positioned conveniently between the AF mode selector switch and the standard 4-button array surrounding the OK button on the back of the camera. All these buttons perform clearly-labeled dual functions, and the K-5 is one of the few cameras of its level of sophistication that can be easily mastered without frequent reference to the, clear, well organized instruction manual.
Another big plus is the LCD. It has a particularly legible and attractive full-info display, including graphics that indicate which dial to use to change apertures and shutter speeds, and clear readouts of all major settings and functions. I loved the fact that the LCD display also rotates automatically from horizontal to vertical orientation when you turn the camera—a great feature for anyone who likes to shoot in Live View or compose on the LCD.
The one control I found confusing was the drive mode button used for selecting single frame, continuous, self-timer, bracketing sequence, and mirror up. It’s adorned with a self-timer icon that’s a bit counter-intuitive, but I soon got used to it.
Shooting with the K-5 is generally a very pleasant experience because the camera is compact, relatively light, feels very solid and well balanced, is very comfortably contoured, and it has a great 100% viewfinder that provides an excellent balance between high brightness and good contrast for manual focusing and assessing fine detail. The LCD also displays captured images with commendable crispness and color accuracy at the standard brightness and contrast settings.
AF noise is about average, but it sounds louder than it is because the shutter-firing sound is so incredibly low by comparison. In terms of shutter/mirror-firing noise the K-5 has got to be one of the quietest shooting DSLRs in production, and this is a major plus for anyone who needs to shoot pictures discreetly. Discounting AF, it’s almost as quiet as my favorite Leica!
Self-portraits at high ISOs: Close-up picture shot at the K-5’s top ISO setting of 51,200 shows remarkably good image quality at this elevated speed—good enough for a decent 5x7 or 8x10 print-but digital “grain” and noise are apparent. Second portrait at ISO 1600 taken at a greater distance is technically outstanding in every respect and easily enlargeable to 16x20 without objectionable noise. Data: 50-200mm Pentax VR lens, f/8, normal P mode.
Wins by more than a whisker: In this closeup of the ISO 1600 shot, the K-5 did an outstanding job capturing the fine detail of my beard.
High ISO Image Quality
Another major advantage of the K-5 is its outstanding performance at high ISO settings (see DxO Lab Test results, below, for an analysis of its sensor's image quality performance in lab conditions). As you’d expect, images shot in the ISO 100—to-400 range showed superb detail and color saturation, but this exemplary performance is maintained up to ISO 1600, with barely any “digital grain” or artifacts visible even at 100% on the monitor screen.
Performance at 3200 and 6400 is likewise excellent—mottling in skin tones, especially in shadow areas, or slight roughness at line edges become evident or objectionable only at ultra-high magnifications. In other words, for the majority of shooting applications ISO 3200 and 6400 are perfectly useable settings so long as you don't do any radical cropping or make prints much larger than 16x20.
Performance at the Expanded ISO settings of 25,600 and 51,200 is remarkably good—you’ll be able to get a nice looking 8x10s, maybe even an 11x14 print at these elevated settings, which is really astonishing.
Baby Nathaniel: Cute toddler was illuminated by a single 100-Watt incandescent lamp, resulting in very warm color balance with camera set on AWB (auto white balance). Image quality at ISO 6400 is all one could ask for, and K-5’s built in SR (shake reduction) system allowed us to get a dharp handheld shot at a very slow shutter speed. Data: 50-100mm Pentax WR f/4-5.6 lens at f/6.3. Focal length: 125mm (188mm equivalent) handheld at 1/15 sec.
In the Field
To assess the K-5’s AF, auto-exposure, and high-speed performance, I shot several 7fps sequences of an athletic young couple horsing around in an ice-skating rink in low light. The lighting was truly atrocious—quite dim inside the rink with bright overcast daylight streaming in below the roof to fool the metering system. I had to shoot at ISO 6400 to get action-stopping shutter speeds, with the camera set on continuous, multi-zone-pattern AF to test the camera’s AF speed and focus-tracking capability.
My results may not be outstanding as sports images, but they certainly are critically sharp, well exposed, and capture exactly what I saw with our naked eyes. Based on our overall shooting experience over more than two weeks, I knew that the K-5’s AF and AE systems are very good indeed, but this certainly confirmed that the camera’s auto-focusing and auto-exposure systems are fast, responsive, and deliver outstanding real-world performance even under challenging conditions.
I was also quite impressed with the imaging performance of our two test lenses—the Pentax 18-55mm WR and 50-200mm WR—which, like the camera, have weather-resistant seals. I shot outdoors with the K-5 during a brief spate of “wintery mix” (snow showers, sleet and rain) I encountered in 15-20-degree temperatures, and the outfit performed flawlessly.
Our only complaint: Metal-bodied cameras such as the K-5 become very cold to the touch in frigid weather. The upside: The K-5 passed our impromptu “gloved operation” test with flying colors! While I did not actually do a comparison test the camera’s shake-reduction (SR) system, I did shoot a few handheld frames at the 70mm (105mm equivalent) setting at ¼ sec that were critically sharp at the point of focus—that’s about a 4-stop advantage over the one-over-the-focal-length rule!
Auto HDR sequence: How effective is the K-5-s Auto HDR mode, which merges +3EV, correct metered exposure, and -3EV shots into a single image? Very, and here are the pictures to prove it! Spot metering for the face (left) gives reasonable skin tones with a blown out background. Metering for the background (center) give a silhouette with correctly exposed (out of focus) curtains in background. Auto HDR gives by far the best overall result under these challenging lighting conditions, and it does it instantly and automatically. More DSLRs should have this feature pioneered by Pentax and probably will.
However, I did take a few shots to test out the automatic HDR function by having a local pro take a few casual portraits of yours truly against a severely backlit background. The system, which takes three shots—one at +3EV, one at the camera’s correct exposure, and another at-3EV and combines them into one works like a charm. The end result is much better than I could have achieved on my own, and was executed automatically and almost instantly. Since this is accomplished through the magic of software, you can expect to see this feature, which was pioneered by Pentax with the K-7, on many future DSLRs.
Finally, I checked out the K-5’s 1080p HD video capability at 25fps by shooting a few video clips and assessing the results. Aside from the lack of autofocus during shooting (the camera auto-focuses once and then maintains that point of focus during each take) the results looked splendid on my 42-inch TV screen, and the sound was reasonably good even though I used the camera’s built in mike instead of plugging in an accessory stereo mike.
For the record, most HD-capable DSLRs do not provide active AF when shooting video, but Sony has a few that do and this is generally an up-an-coming feature. Many video shooters use manual focus with satisfaction and there are many gizmos on the market that facilitate manual focus on the fly with DSLRs.
Lab test results (Provided by DxOMark):
Maximum ISO for acceptable image quality (digital noise): ISO 1600
Maximum ISO for acceptable dynamic range: ISO 1600
Color depth: Outstanding (23.7 on a scale of 1-25)
Overall image quality: Outstanding (82 on a scale of 1-100)
Dynamic range: Up to 14.1 stops
The Pentax K-5 just barely edges ahead of the Nikon D7000 for best low light/high ISO test results of any APS-C DSLR, and is the clear leader when it comes to dynamic range with an impressive 14.1 stops. Measured ISO sensitivity is within 1/3 stop of the indicated speed at all ISOs, and the signal to noise ratio really doesn’t dip into the super-grainy side until ISO 6400. As our field shots demonstrate, when shooting JPEGs with noise-reduction turned on, you can get very good results all the way up to ISO 6400 and usable results (albeit with significant graininess) at higher ISO's.
Conclusion and recommendation
After shooting exhaustively with the Pentax K-5, I conclude that it is a robust, reliable, beautifully made, very well thought out, high-performance camera that provides an impressive array of features along with prosumer-level performance at a very attractive price point.
In terms of value in this fiercely competitive sector of the market, it may not quite be unequalled, but it is definitely unsurpassed. When you consider the caliber of some of its recently introduced competitors, that’s really saying something.
The bottom line: Any advanced shooter who is not heavily invested in another system should seriously consider the Pentax K-5, especially if body build, a fast framing rate, high-ISO performance, and quiet operation are deciding factors.