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Pentax K10D Digital Camera Full Review
by Howard Creech -  3/22/2007

The Pentax K10D dSLR - Designed by photographers for photographers 

Pentax's K10D flagship dSLR is up against some pretty stiff competition from Canon’s EOS 30D and Nikon’s D80, but for many users the K10D may actually be the best deal in the mid-level dSLR class.  K10D features include 10 Megapixel resolution, image stabilization, very fast AF, an automatic CCD dust removal system, support for two RAW formats, a robustly constructed dust/weather resistant body, a super bright Pentaprism viewfinder, mirror lock-up, digital and analog depth of field (DOF) previews, and a selection of unique user-driven shooting modes. The K10D provides a logical control layout plus a full range of manual exposure options and image parameter tweaks.  In addition, the K10D is dependably quick across the board; noticeably faster than the K100D I tested last summer.  The K10D was obviously designed by photographers, for photographers - this dSLR is aimed at photo enthusiasts, rather than those upgrading from point digicams. 

pentax K10d
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NUTS & BOLTS

Viewfinder

The K10D features a bright TTL pentaprism optical viewfinder that shows 95 percent of the image frame.  The K10D's optical viewfinder highlights the selected AF focus point (users can opt for Auto AF-point selection, manual AF point selection, or center AF point) and there’s a comprehensive settings/status/function readout.  There's also a diopter correction for eyeglasses wearers.  The rubber-like eyecup is removable and Pentax supplies an eyepiece blind that can be inserted to prevent stray light from entering the viewfinder during long exposures.

LCD Screen

The LCD screen on the K10D's rear deck can't be used as a viewfinder (like it is with point & shoot digital cameras) because the mirror used to reflect the image resolved by the lens blocks the light path (preventing the transmission of a live image feed). The K10D’s LCD screen, like the LCD screens on the vast majority of digital SLRs, is used for menu navigation and post-exposure image review.  The K10D's full info 2.5” (210,000 pixel) TFT LCD screen is bright (brightness levels can be adjusted), hue accurate, and shows almost 100% of the image frame. Pentax didn’t provide an anti-reflective coating for the LCD screen and the mirror like plastic protective LCD cover makes image review more difficult in bright lighting, but the LCD screen does feature a 140 degree viewing angle. Image magnification (for reviewing captured images) is accomplished quickly and easily via the rear e-dial (thumbwheel).  There’s a histogram display (for checking over/under exposure and dynamic range) in case the need to re-shoot arises.  Under the K10D’s default settings each image is briefly displayed, post capture. Image review options (activated via the info button) include overlaying either a standard histogram display or a combined standard - red/green/blue channels histogram display plus blinking bright (over-exposed) / dark (under-exposed) areas.

pentax K10d
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Lens Mount/Optics

The K10D permits users to mount virtually every Pentax mount lens ever manufactured, including all KA mount lenses (KA, KAF, KAF2, KAJ, and Pentax DA optics).  K-mount manual focus lenses are usable (with restrictions) and Screw (M-42) mount MF lenses and Pentax 67/645 MF optics are usable with adapters.

There are literally thousands of cheap used manual focus K-mount and M-42 (Screw mount) lenses available (from ultra-wide to long telephoto) and that exponentially expands creative possibilities for K10D users.  Nikon’s famous backward compatible F/AF mount doesn’t come close to providing the astonishing optical versatility offered by the K10D - and every lens (no matter how ancient) benefits from the K10D’s image stabilization technology. 

The K10D's APS-C (23.5mm x15.7 mm) sized CCD sensor is smaller than a frame of 35mm film (36mmx24mm) so the focal length of 35mm format lenses is multiplied by 1.5X - telephoto lenses magically grow longer (a 200 mm telephoto becomes a 300 mm telephoto), but the same thing happens to wide-angle lenses (a 28 mm wide-angle lens becomes a 42 mm normal lens). 

Auto Focus (AF)

The K10D uses a TTL phase-matching 11 AF point contrast detection auto focus system similar to AF system on last years Pentax K100D/K110D models.  The camera automatically selects the closest AF point to the subject (closest subject priority) and that AF point glows red, once focus is locked.  AF is consistently fast and accurate (noticeably faster that the K100D) even in dim/low lighting.  Continuous AF (which continually adjusts focus as the shooter tracks a moving subject) works pretty nicely in most action/sports shooting situations. 

Manual Focus (MF)

Manual focus with the K10D is easy - flip the A/M focus switch to the M position, grip the lens focusing ring and manually adjust focus like “old school” photographers used to do in those primitive days before auto-focus.

Image Stabilization (IS)

The K10D’s image stabilization system (Pentax calls this SR – Shake Reduction) neutralizes camera shake by shifting the camera’s free-floating CCD sensor.  The K10D analyzes input from motion detectors embedded in the camera body and then produces a precisely equal and opposite shift in the CCD to counteract camera shake.  Most camera manufacturers (including Canon and Nikon) accomplish IS by shifting lens elements to counteract camera movement.  The greatest benefit of CCD shift IS systems is that they work with every lens mounted, not just with (more expensive) IS or VR lenses. 

With image stabilization enabled, K10D users can shoot at shutter speeds up to 3 stops slower. For example if a shutter speed of 1/125th of a second is required to avoid the effects of camera shake - the K10D can capture a reasonably sharp picture at 1/15th of a second.  Sharp handheld low light images can be captured easily, at shutter speeds that would normally produce blurry pictures, even with telephoto zooms. Image stabilization won't neutralize hard/sharp camera movements or reduce blur caused by rapidly moving subjects or too fast panning.  

An ancillary benefit of Pentax’s IS system is that it allows the camera to use the same CCD shift technology to shake dust off the sensor - users can program the camera to do the dust reduction/removal cycle at start-up or manually select dust reduction/removal at any time (like immediately after changing lenses). 

Flash

The K10D's built-in P-TTL pop-up multi-mode (Auto, Fill, Auto + Red-eye reduction, Fill + Red-eye reduction, and off) flash is released mechanically (the flash release button is located just below the flash) when the shooter determines supplemental lighting is needed.  The K10D’s built-in flash also functions as the AF-assist lamp - firing a series of brief bursts in rapid succession to help the camera lock focus in dim/low lighting.   Fastest flash synch speed is 1/180th of a second and the Guide Number is 11@ ISO 100/m.  Coverage (field of view) is 18MM and the maximum flash range (with an f2.8 lens) is a bit more than 15 feet.

pentax K10d
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Hot Shoe  

The K100D also provides a dedicated flash hot shoe for mounting Pentax Speedlights like the AF360FGZ or the more powerful AF540FGZ.  Third party flash units can be used, but not with full compatibility.

Storage/Image File Formats/Connectivity  

The K10D saves images to SD/SDHC memory cards.  Digital SLRs do not include a starter memory card (and they don ’t provide any on-board image storage) so K10D purchasers should factor the cost of a fairly large (at least 1 GB) SD or SDHC card into their price calculations/comparisons.

pentax k10d
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Images are saved in JPEG format or 2 RAW formats - Pentax’s PEF RAW format or Adobe’s DNG (digital negative) RAW format

Connectivity: USB 2.0HS, A/V out, and DC in

Power/Battery Life

The K10D draws its juice from a proprietary high-capacity (7.4v 1620mAh) Pentax D-L150 lithium-ion rechargeable battery.  Pentax claims a fully charged D-L150 is good for 500 exposures - I didn’t keep track of exposures so I can’t provide any specific numbers, but based on my use (I had the camera for a month) that seems to be a reasonably accurate assessment.   The included Pentax D-BC50 charger needs about three hours to fully charge the D-L150. 

pentax k10d
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EXPOSURE  

Pentax's dedicated usability engineering (designed by photographers - for photographers) has created an imaging tool that quickly and intuitively becomes an expressive and creative extension of the individual behind the camera.  The K10D is a semi-pro dSLR, so (as expected) it provides users with a comprehensive range of auto/manual exposure options including: User (configurable), Program AE, Hyper-Program AE, Sensitivity priority AE (users choose the ISO sensitivity and the camera selects an appropriate shutter speed and aperture), Shutter-Priority AE, Aperture-Priority AE, Shutter & Aperture-Priority (users select both exposure parameters and the camera boosts or lowers ISO sensitivity to match the selected shutter speed and aperture), Hyper-Manual, and Bulb.  The Sensitivity Priority AE and Shutter & Aperture Priority modes are unique to the K10D (and its Samsung clone).

Metering

The K10D provides users with TTL open-aperture multi-segment evaluative (default), center-weighted, and spot metering.  The default evaluative metering mode is consistently accurate and nicely covers most outdoor lighting situations, but like most digital camera metering systems, the K10D's evaluative metering mode is calibrated to preserve shadow detail at the expense of highlight detail. That built-in exposure bias results in occasional clipping (burnt out highlights). More experienced photographers can opt for either spot (reads only a tiny portion of the image frame allowing users to bias exposure on the single most important element in the composition - like the eyes in a head and shoulders portrait) metering or center-weighted average (biases exposure on the central portion of frame - great for classic landscape shots and travel images where the subject is likely to be centered) metering for more demanding/creative compositions.

pentax k10d sample image
(view medium image) (view large image) The vast expanse of bright blue sky in this “S” curve grab might have confused the metering systems of many digital cameras, but the K10D’s multi-segment evaluative metering rendered each element of the composition accurately. SMC Pentax f4.0-f5.6/18-35 FAJ zoom

I do have one minor complaint with the K10D's light metering system - its inability to link spot metering to a single AF point (allowing the photographer to align the AF target with the most important element in the composition and tie the camera ’s metering to that same spot).  Most of Canon's upper tier P&S digicams offer this feature - a semi-pro dSLR should definitely provide this option.

White Balance

The K10D's white balance options include: TTL (through the lens) Auto, and user selectable settings for Daylight, Shade, Cloudy, tungsten, Fluorescent (White, Neutral, Daylight), flash, Color Temperature, and 2 Custom (Manual) modes.

pentax k10d sample image
(view medium image) (view large image) This indoor close-up shows just how good the K10D’s auto white balance mode really is -  mixed fluorescent and window (daylight) lighting. Pentax SMC-DA f2.4/70mm LE prime lens

Sensitivity

The K10D provides a truly impressive (and highly useful) selection of sensitivity settings including TTL Auto and user selectable settings for 100, 125, 160, 200, 250, 320, 400, 500, 640, 800, 1000, 1250, and 1600 ISO. 

In-Camera Image Adjustment

In camera image adjustment options are very important because they allow savvy shooters to immediately counter environmental/lighting problems and to more precisely reflect their personal creative vision by tweaking exposure compensation, bracketing exposures, and incrementally adjusting color saturation, contrast, sharpening, and white balance. The K10D provides a full complement of in-camera exposure adjustment options.  This is one of the most seriously "tweakable" cameras I have ever used.  

CONTROLS, DESIGN, & ERGONOMICS

The K10D is a slightly chunky very traditional looking pro-black dSLR that displays a clear family resemblance to the K100D and K110D.  The K10D is larger and heavier than its siblings; in fact it is the heaviest dSLR in its class. The K10D’s polycarbonate body shell 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.  The built-in handgrip and its rubber-like covering provide a very secure hold and a stable balance point (for right handed shooters). Controls are logical, well placed, and quickly become intuitive.  The Fn button (direct access to Sensitivity, Flash, White Balance, and Drive Mode settings), Exposure Compensation button, dedicated RAW button, and twin E-dials are well placed and easily accessed. 

pentax k10d
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PERFORMANCE  

Image Quality  

dSLR image quality is dependent on a combination of factors: the quality of the lens mounted, the efficacy of the CPU (image processing), and the accuracy of the exposure system. Default JPEG images from the K10D are a bit soft and native (default) colors are a little flat, but that's due to Pentax's minimal sharpening and image interpolation.  Users can customize images by selecting the Bright Image Tone option and tweaking color saturation, contrast, and sharpening to precisely match personal taste.  Based on results with the three lenses I used for my tests, the K10D’s image quality is dependably pro quality, with very good detail capture in highlight areas, superior detail capture in shadow areas, and crisp edge transitions. Noise is virtually non-existent up to ISO 400, very well managed up to ISO 800, and visible but not objectionably so from ISO 1000 to ISO 1600.

Once users adjust tone, color saturation, contrast and sharpening - colors are bright, vibrant, nicely saturated, and hue accurate.  Tweaked images show a wide dynamic range and good tonal balance. Chromatic aberration (purple fringing) was remarkably well controlled with the three lenses I used, but Chroma noise (blotching) is visible at the highest ISO settings - due to the K10D's minimal NR (noise reduction). Tweaked JPEG images are impressive, almost equal to the K10D's RAW images.  There is a very slight tendency toward over-exposure (in all AE modes) and occasional burnt out highlights, but shadow detail is reliably impressive.  RAW images (in either format) are dependably and consistently excellent.

pentax k10d sample image
(view medium image) (view large image) Most digital cameras can render primary colors (red, yellow, and blue) reasonably well, but secondary colors (green, purple, orange) are often more challenging.  This faded fifties color scheme doorway and exuberantly decorated gate showcase the K10D's superb color interpolation.  Image cropped slightly to remove an extraneous detail.  SMC Pentax f4.0-f5.6/18-35 FAJ zoom

Lenses used - a Pentax SMC-DA f2.4/70mm LE prime lens (provided by Pentax) and an SMC Pentax f4.0-f5.6/18-35 FAJ zoom and a Pentax SMC f4.5-f5.6/80-200 FA zoom (generously lent by used camera merchant Chuck Rubin  – www.chuckrubin.com).  Image quality obtained with the Pentax SMC DA f3.5-f5.6/18mm-55mm kit zoom may differ. 

Timing/Shutter Lag  

The K100D I tested last summer was a bit slower than its competition.  The K10D doesn't suffer from that malady; this dSLR is reliably quick and responsive across the board.  Start up is virtually instantaneous (unless dust reduction/removal is enabled).  The K10D’s IS system and AF systems work together beautifully with virtually no IS/AF lag.  This is very impressive because the IS process adds to the time interval that passes between pushing the shutter button and the moment when the shutter actually fires.  AF lock is essentially real time with pre-focus and about 1/4 of a second from scratch.   Shot to shot times and write to card times (for JPEG images) are equal to or better than the K10D's competition.  Most action shots shouldn't provide any problem, even rapid action team sports should be a snap. 

Memory media used for my timing tests - SanDisk Ultra II 4GB SDHC card.

pentax k10d sample image
(view medium image) (view large image) The K10D easilty captured this tack sharp (IS enabled) handheld shot of a BMX biker suspended in mid air. Pentax SMC-DA f2.4/70mm LE prime lens

A Few Concerns

The Pentax catalog is seriously lacking in long lenses.  Those who need a true system camera (to shoot team sports, wildlife, or celebrities) are currently better off with Nikon or Canon.  Pentax is in a good position to challenge the big boys and move into the camera major leagues - something they've been trying to do for more than fifty years.  Here are a couple of suggestions - seek some financial support from new owner Hoya for R&D on a true pro-level Pentax dSLR - The K100D/K110D models did a nice job of resurrecting the iconic K1000 as a dSLR - how about resurrecting the classic LX as a pro dSLR?  In the interim, negotiate a deal with Sigma and/or Tokina to re-badge a couple of long fast primes and a pro-quality fast zoom or two for K100D/K110D and K10D users. 

Conclusion

Canon and Nikon currently dominate the semi-pro dSLR market, but all any camera maker has to do to unseat the sales leaders is to offer a better product at a lower price.  The introduction of the Pentax K10D is a big step in that direction.  The K10D offers several unique benefits the majors can't match including image stabilization with every lens, pro quality dust/weather/moisture seals, two RAW formats, and an automatic dust reduction/removal system - all at a very competitive price.  Serious shooters may have a few issues (like Pentax's lack of long glass), but for many photographers - including those with a closet full of old FA, KA, or K-mount lenses, the K10D may be just the camera they've been looking for.  I really liked the Pentax K10D - it was clearly designed by photographers - for photographers.  Amateur photographers looking a camera that can keep pace as their photographic skills develope should seriously consider the Pentax K10D - this dSLR is a contender. 

The Pentax K10D retails for less than nine hundred bucks - add the Pentax DA f3.5-f5.6/18mm-55mm kit zoom for a hundred dollars more.

Technical Specifications

Included

D-L150 lithium-ion rechargeable battery, D-BC50 battery charger, Viewfinder blind cap, Hot shoe protective insert, Neck strap, USB cable, Video cable, software CD ROM, camera manual (printed)

Optional

D-BG2 Battery Grip, Pentax AF360FGZ and AF 540FGZ flash units, Pentax SMC-DA f2.4/70mm LE prime lens and Pentax SMC-DA f3.2/21mm LE prime lens

Pros: Solid build-quality with dust/weather/moisture seals, excellent image quality, digital and analog depth of field preview, Image stabilization with every lens, and automatic dust reduction/removal system

Cons: Battery life is a bit below average