Pentax K-x Review

Look and Feel

The K-x is a compact digital SLR with a plastic outer shell and a stainless steel chassis inside. Despite the plastic shell, the body feels quite solid, especially given the price of the camera. I found the camera comfortable to hold, thanks to a good-sized, rubberized right hand grip. Pentax has done a good job at keeping buttons to a relative minimum. All of the buttons are large, well-labeled, and usually serve just one function. It was nice to see that the K-x still has a control dial -- many of its competitors do not.

Pick your color...
Images courtesy of Pentax

Pentax sells the K-x in some pretty bold colors, to say the least. If you want something conservative, stick with black or navy. Fans of Star Wars may like the white model, while those who really want to stand out in a crowd may gravitate toward the red model.

Alright, now let's see how the Pentax K-x compares to other cameras in its class in terms of size and weight:

Camera Dimensions (W x H x D, excluding protrusions) Volume (bulk) Mass (empty)
Canon EOS Rebel XS 5.0 x 3.8 x 2.4 in. 45.6 cu in. 450 g
Nikon D3000 5.0 x 3.8 x 2.5 in. 47.5 cu in. 485 g
Olympus E-620 5.1 x 3.7 x 2.4 in. 45.3 cu in. 475 g
Panasonic Lumix DMC-G1 4.9 x 3.3 x 1.8 in. 29.1 cu in. 385 g
Pentax K-x 4.8 x 3.6 x 2.7 in. 46.7 cu in. 516 g
Samsung NX10 4.2 x 3.4 x 1.6 in. 22.8 cu in. 349 g
Sony Alpha DSLR-A380 5.0 x 3.8 x 2.8 in. 53.2 cu in. 489 g

If you ignore the two mirrorless (and therefore much smaller) cameras from Panasonic and Samsung, you'll find the the Pentax K-x is quite average in terms of size, and a little heavier in the weight department. It's certainly not a bulky camera. but don't expect to by carrying it around in your jacket pocket, either.

Ready to tour the K-x now? I know I am, so let's begin!

Front of the Pentax K-x

Here's the front of the K-x, without a lens attached. The camera supports all Pentax K-mount lenses, plus old screw-mount and 645/67 medium format lenses (though an adapter is required for those). All but the oldest lenses should support autofocus, and most will work with the camera's image stabilizer right out of the box. The more modern DA, DA L, and D FA lenses support automatic aberration and distortion correction, as well. To release a lens, simply press the button to the lower-left of the mount.

As I just hinted at, the K-x has a sensor-shift image stabilization system, like all Pentax D-SLRs. The camera detects the tiny movements of your hands that can blur your photos, especially in low light, or when using a telephoto lens. The K-x physically moves the sensor to compensate for this motion. Pentax says that the IS system opens up 4 stops of shutter speeds that you couldn't use otherwise. Want to see the IS system in action? Here, have a look:

Image stabilization off

Image stabilization on

I took both of the above photos at 1/5 of a second, which is pretty slow. As you can see, the image stabilizer does its job well, producing a noticeably sharper image. You can also use the K-x's image stabilizer to smooth out your videos, though the system makes quite a bit of noise, which may be picked up by the camera's microphone. Here's an example of how the shake reduction system smoothes out your videos. I left the sound track in this sample movie so you can hear the noise generated by the IS system.

The camera also uses the shake reduction system to remove dust from the sensor, though this feature is not turned on by default. When you do turn it on, the camera will shake the sensor rapidly when it's powered on, and you can also run the system manually at any time.

Directly above the lens mount is the K-x's pop-up flash, which is released electronically. This flash has the typical guide number of 12 meters at ISO 100. Should you want more flash power, you can attach an external flash to the hot shoe that you'll see in a moment, or cut the cord entirely and go wireless, using the built-in flash as the master.

Over on the grip you can see the receiver for the optional wireless remote control, which has the self-timer lamp right next door. If you're wondering about an AF-assist lamp, the K-x uses its built-in flash for that purpose. It's can be quite blinding to people and animals, but it does allow the camera to focus in very low lighting.

Back of the Pentax K-x

The first thing to see on the back of the K-x is its 2.7" LCD display. The screen has a resolution of 230,000 pixels though, to be honest, it didn't seem that sharp in reality. I found the screen fairly easy to see outdoors, though its viewing angle leaves something to be desired.

The view in live view mode Zoomed in 4X in live view mode

As with all D-SLRs these days, the LCD isn't just used for menus and reviewing photos -- you can also use it for taking photos, too. The "live view" feature on the K-x is pretty standard, but well implemented. You can compose your photo with 100% coverage, preview exposure and white balance, view a histogram and/or grid lines, and enlarge an area of the frame. This last feature lets you zoom into a photo by as much as 10 times and then move around, which allows for very precise manual focusing. One thing I didn't care for was the low light visibility in live view -- the screen doesn't "gain up" very much, so it's very hard to see your subject.

There are three autofocus modes available in live view mode: face detection, contrast detect, and phase difference AF. The first two both use the camera's CMOS sensor for focusing, and the face detection feature is capable of locating up to 16 faces in the frame. You can also move the AF target anywhere in the frame by using the four-way controller. The problem with contrast detect AF on digital SLRs is that it's slow -- very slow. While a compact camera might lock focus in half a second, the K-x can take one, two, or three seconds to do the same thing. In other words, it's not for action shooting. The good news is that Pentax provides phase difference AF as well, which uses the same dedicated autofocus sensor that you'd get when shooting with the viewfinder. The only real differences are that the live view disappears for about a second while the camera focuses, and that face detection is not available. This mode is always the one I choose on cameras that offer it.

Live view is also the place where you'll record movies -- but I'll save that for later.

Info display, with a virtual four-way controller Press the Info button again to get to this screen, where you can quickly change camera settings

When the LCD isn't being used for live view, it can be turned into an information display, which shows the current camera settings. An additional screen (accessed by pressing the Info button) lets you adjust numerous camera settings (see screenshot). These settings include:

  • Custom image
  • Cross processing
  • Digital filters
  • HDR capture
  • Shake reduction
  • AE metering
  • AF mode
  • Select AF point
  • Highlight correction
  • Shadow correction
  • FIle format
  • JPEG recorded pixels
  • JPEG quality
  • Distortion correction
  • Lateral chromatic aberration adjustment

Needless to say, I'll explain all of those in detail when I get to the menu section of this review.

Getting back to the tour now, let's talk about the K-x's optical viewfinder. The viewfinder is one of the few design-related annoyances on the K-x in my opinion. It has nothing to do with the coverage or magnification of the viewfinder, which are 96% and 0.85, respectfully. Rather, it's the fact that the camera does not show the current focus point in the viewfinder, unlike every other D-SLR on the market. There's no way for the user to know what area of the frame the camera locked focus on, unless you're using center-point AF. While I understand that some features need to be removed to keep the price down on a camera, this is one that definitely should not have been cut. At least you still get the line of information under the field-of view, which displays the shutter speed, aperture, focus lock, ISO, and exposure compensation setting (the number of shots remaining is not displayed). You can adjust the focus of the viewfinder by using the diopter correction slider on its top side.

To the left of the viewfinder is a button which releases the built-in flash, and it also is used for deleting photos. On the opposite side you'll find the camera's one and only command dial -- used for adjusting manual settings, navigating menus, and enlarging photos -- and the AE/AF lock button.

Now let's talk about the four buttons located to the right of the LCD. They include:

  • Playback mode
  • Live view - turns this on and off
  • Info - toggles what's shown on the LCD
  • Menu

To the right of those is the four-way controller, used for menu navigation, selecting a focus point, moving through photos you've taken, and also:

  • Up - Drive (Single shot, continuous lo/hi, 2 or 12 sec self-timer, 0 or 3 sec remote control, exposure bracketing)
  • Down - Flash setting (Flash on, flash on + redeye reduction, slow sync, slow sync + redeye reduction, trailing curtain slow sync, wireless mode) + flash exposure compensation (-2EV to +1EV, 1/3EV increments)
  • Left - White balance (Auto, daylight, shade, cloudy, fluorescent x 4, tungsten, flash, color temperature enhancement, manual)
  • Right - ISO sensitivity (Auto, 200 - 6400)
  • Center - OK + focus point select

There's plenty to talk about before we can continue the tour. Let's start with the drive options, specifically the two continuous shooting choices. There are low and high speed continuous modes, and here's what kind of performance you can expect from the K-x:

Quality setting Low speed High speed
RAW+ JPEG (12M/Best) 5 shots @ 1.9 fps 4 shots @ 4.4 fps
RAW 10 shots @ 1.9 fps 5 shots @ 4.6 fps
JPEG (12M/Best) 35 shots @ 1.8 fps 21 shots @ 4.6 fps
Tested with a Panasonic Class 10 SDHC card

While it doesn't have a lot of buffer memory, the K-x does have the fastest burst rate in its class. When you hit the limits I listed in the table above, the camera doesn't stop shooting -- it just slows down considerably. Do note that the live view will shut off after the first shot when shooting continuously, so you'll probably want to track your subject using the optical viewfinder.

The drive menu also contains the camera's AE bracketing feature. With this turned on, the camera will take three photos in a row, each with a different exposure compensation setting. The interval between each of the shots can be as little as 1/3EV, or as much as 3EV.

Lots of white balance choices Plus the ability to fine-tune

Now onto white balance, where the usual presets like tungsten and sunlight are just the beginning. Each of those presets can be tweaked, as you can see above. You can also use a white or gray card for accurate color in mixed or unusual lighting. There's also a unique Color Temperature Enhancement (CTE) option, which Pentax describes as the opposite of auto white balance. For example, if the camera is using a high color temperature, CTE will crank it up a little higher, to emphasize the colors in the scene. So what can't you do? You can't set the color temperature, and there's no WB bracketing feature.

Adjusting the ISO sensitivity

In the ISO menu, you can select a set value, ranging from 200 - 6400, which is expandable to 100 - 12,800. You can also use Auto ISO, which allows you to select the upper limit that the camera will use. We'll see how the K-x performs throughout its ISO range later in the review.

And that's it for the back of the camera!

Top of the Pentax K-x

You may not notice it at first, but the first thing to see on the top of the K-x is its microphone, which is located toward the left side of the photo. The camera records monaural sound, and does not have an input for a stereo microphone.

In the center of the photo is the K-x's hot shoe. As I mentioned earlier, you'll get best results by using a Pentax flash, as they'll sync up with the camera's metering system. The two top-end Pentax flashes (the AF360FGZ and AF540FGZ) also support high speed flash sync, use of their AF-assist lamps, and they can also serve as wireless flash transmitters (as can the built-in flash). If you're using a non-Pentax flash, you may have to set the exposure on both the camera and flash manually. Unless you're using high speed flash sync, the maximum shutter speed you can use with an external flash is 1/180 sec.

Continuing to the right, we find the K-x's mode dial, which is packed with options. Here's the full list:

Option Function
Auto Picture mode Point-and-shoot, with auto scene selection, most menu options locked up.
Scene (SCN) mode You pick the situation, and the camera selects the proper settings. Choose from night scene, surf & snow, food, sunset, stage lighting, kids, pet, candlelight, museum, and night snap.
Movie mode More on this later
Program mode Automatic, with full menu access. You can move through various shutter speed/aperture combinations by using the command dial (Program Shift). An option in the custom setting menu allows you to adjust the shutter speed or aperture instead.
Sensitivity priority (Sv) mode You set the desired ISO sensitivity, and the camera will select the appropriate shutter speed and aperture to obtain an accurate exposure.
Shutter priority (Tv) mode You choose the shutter speed, and the camera picks the appropriate aperture. Shutter speed range is 30 - 1/6000 sec.
Aperture priority (Av) mode You choose the aperture, and camera picks the shutter speed. Range depends on lens used. For the 18 - 55 mm kit lens, it's F3.5 - F40.
Manual (M) mode You select the shutter speed and aperture yourself. A bulb mode is also available, allowing for exposures as long as you hold down the shutter release is held down.
Flash off Disables the flash, including for AF-assist.
Night scene portrait The most commonly used scene modes have dedicated spots
Moving object

Scene menu

The K-x has both automatic and manual controls, which should satisfy just about everyone. On the point-and-shoot side, there's the Auto Picture mode, which selects one of six scenes automatically (two more are available when using live view). You can also select a scene mode yourself, with plenty to choose from.

As for manual controls, you've got the usual suspects: program, shutter priority, aperture priority, and full manual. There's also the unique sensitivity priority mode, where you set the ISO and let the camera figure out the rest. The K-x does not have the TAv mode that's found on the more expensive K-7, nor is there a dedicated spot on the dial for your favorite camera settings.

Above the mode dial are the exposure compensation and "green" buttons. The former does just as it sounds, with an available range of -3EV to +3EV. The green button is customizable, and by default it returns the exposure settings to their defaults (I'll list the other options later).

In-between those buttons is a blinding blue power lamp, which thankfully can be dimmed or shut off altogether in the setup menu. Just north of that is the shutter release button, which has the power switch wrapped around it.

Side of the Pentax K-x

There are just two things to point out on this side of the Pentax K-x. The first is the switch between auto and manual focus, with the second being the camera's single I/O port, which is under a rubber cover. This port is for USB and A/V output. The K-x does not have an HDMI port, though I wouldn't really expect one, given its price.

Side of the Pentax K-x

On the other side of the camera you'll find its SD/SDHC memory card slot, which has a plastic door of average quality protecting it.

The only other thing to note here is the tiny flap through which you pass the power cord for the optional AC adapter.

Bottom of the Pentax K-x

Let's end our tour with a look at the bottom of the K-x. Here you can see the metal tripod mount, which is -- of course -- in line with the lens. The other thing here is the battery compartment, which holds four AA batteries (yay!). The door is fairly sturdy, and includes a locking mechanism.