Pentax K-3 II Exposure

Saturation & Hue Accuracy
High mean saturation, with average hue accuracy.

Saturation. The Pentax K-3 II's default image tone setting of "Bright" pushes most colors by quite a bit at base ISO, especially blues, dark greens, dark reds and purples. Mean saturation at ISO 100 is 117.9% or 17.9% oversaturated. That's about 8% higher than most other brands at default settings. Overall, colors are very bright and punchy, a trait we've come to expect from Pentax, and mean saturation remains higher than average throughout the ISO range, peaking at 123.2% at ISO 25,600. You can of course always select a different image tone preset and/or turn down saturation and contrast settings to suit your own tastes. Most consumer digital cameras produce color that's more highly saturated (more intense) than found in the original subjects. This is simply because most people like their color a bit brighter than life.

Skin tones. Caucasian skin tones from the Pentax K-3 II were a touch yellow using Manual white balance in our test shots, however Auto white balance produced a slightly more pinkish, "healthier" appearance. Good results here. Where oversaturation is most problematic is on Caucasian skin tones, as it's very easy for these "memory colors" to be seen as too bright, too pink, too yellow, etc.

Hue. The Pentax K-3 II's mean "delta-C" color error of 5.26 after correction for saturation at ISO 100 is about average for a DSLR these days. Most noticeable were moderate shifts in orange toward yellow and cyan toward blue, with minor shifts and some reds, yellows, and greens. (The cyan to blue shift is very common among the digital cameras we test; we think it's a deliberate choice by camera engineers to produce better-looking sky colors.) White balance shifts towards magenta at higher ISOs, which helps to increase mean color error to a maximum of 6.59 at ISO 25,600, though that's still pretty good for such a high ISO. Hue is "what color" the color is.

Exposure and White Balance

Indoors, incandescent lighting
Very warm results with Auto white balance, but good color with Incandescent and Manual white balance settings. Slightly higher than average exposure compensation required.

The Pentax K-3 II's Auto white balance setting had a difficult time with the very warm color of the household incandescent bulbs used in this shot, producing a very warm image with a strong orange tint when using the default "Strong" Correction option; a "Subtle" Correction setting is also available, which would produce even warmer results. Results with the Incandescent setting are actually pretty good, though, just slightly on the cool side. The Manual setting produced the most accurate color balance, though still just a touch cool. Note that a Kelvin setting is available, as well as Color Temperature Enhancement (CTE) white balance option which exaggerates the temperature of ambient light. The Pentax K-3 II required +0.7 EV exposure compensation for a good exposure, which is slightly higher than the average of +0.3 EV for this shot. Our test lighting for this shot is a mixture of 60 and 100 watt household incandescent bulbs, a pretty yellow light source, but a very common one in typical home settings here in the U.S.

Outdoors, daylight
Very bright, slightly cool colors with about average exposure accuracy.

The Pentax K-3 II handled tough outdoor lighting under harsh sunlight well, producing very bright though slightly cool colors. Default contrast is on the high side (as most users prefer), resulting in some clipped highlights in the mannequins's shirt and some of the flowers, as well as some lost shadows below the flowers and in the background, though all but the deepest shadows were quite clean if a bit posterized. +0.7 EV exposure compensation was required to keep the mannequin's face bright, which is about average for this scene. Skintones were just a touch warm and yellow using Manual white balance, so we preferred Auto white balance for our "Sunlit" Portrait shot here. Our Far-field shot was well exposed at 0 EV, and again with punchy, slightly cool color. Only a few highlights were clipped and very few shadows were lost, with very good detail in the shadows as well. Very good results overall here.

See full set of test images with explanations
See thumbnails of all test and gallery images

Native Resolution
~2,700 to ~2,750 lines of strong detail from JPEGs, about the same from converted RAW files.

Our laboratory resolution chart reveals sharp, distinct line patterns down to about 2,700 lines per picture height in the horizontal direction, and to about 2,750 lph in the vertical direction in best quality JPEGs, though some aliasing can be seen at around 2,300 lph. Complete extinction of the pattern didn't occur until just past 3,000 lines in both directions. An Adobe Camera Raw conversion yielded the same numbers, though individual lines were more crisp up to the same resolution, and complete extinction of the pattern was extended past 3,800 lines. The ACR processed RAW images do however show a lot more color moiré, as they often do. (Note that AA Simulation was set to its default of off, for maximum resolution.) Use these numbers to compare with other cameras of similar resolution, or use them to see just what higher resolution can mean in terms of potential detail.

Pixel Shift Resolution Mode
~2,850 to 2,900 lines of strong detail from JPEGs, about the same from converted RAW files.

The Pentax K-3 II's Pixel Shift Resolution mode yielded slightly higher resolution from in-camera JPEGs at about 2,850 lph horizontally and 2,900 lph vertically, but there were strong aliasing artifacts in the form of moiré patterns starting as early as 1,900 to 2,000 lines. Adobe Camera Raw produced fewer aliasing artifacts, but lines began to merge and false colors were generated at about the same resolution as the JPEGs, however complete extinction of the pattern didn't occur before the 4,000 line limit of our chart.

Click here for lots more on the Pentax K-3 II's Pixel Shift Resolution mode.

See full set of test images with explanations
See thumbnails of all test and gallery images

Sharpness & Detail
Very sharp images with excellent detail, though with moderate edge-enhancement on high-contrast subjects. Minor noise suppression visible at base ISO.

Sharpness. The Pentax K-3 II produces very sharp images with excellent detail at default settings. Images are somewhat oversharpened as edge enhancement artifacts are visible on high-contrast subjects such as the sharpening halos around the lettering and border in our Mas Portell bottle label above left, but overall results are still quite good with very crisp looking images. Edge enhancement creates the illusion of sharpness by enhancing color and tonal differences right at the edge of a rapid transition in color or tone.

Detail. The crop above right shows only minor detail loss due to noise suppression. Individual strands are still distinguishable even in the lighter shadows, though they begin to merge as shadows deepen, and in places where the tone and color of adjacent strands is very close. Still, very good performance here. Some individual strands of hair do show aliasing artifacts in the form of "jaggies", however the K-3 II's selectable AA filter should help prevent those from occurring when enabled (AA Filter Simulation was disabled by default). Noise-suppression systems in digital cameras tend to flatten-out detail in areas of subtle contrast. The effects can often be seen in shots of human hair, where the individual strands are lost and an almost "watercolor" look appears.

Anti-aliasing Filter Simulator
During the exposure, the Pentax K-3 II's anti-shake actuator can oscillate the sensor assembly microscopically in either a linear (Type 1) or circular (Type 2) motion, simulating the effects of an anti-aliasing (or optical low-pass) filter. To see the effect on image sharpness and aliasing artifacts, roll over the links in the table below to compare the USAF Resolution target and green/black starburst taken from our Multi target at base ISO:

As you can see above, AA Filter Simulation Type 1 blurs fine detail slightly, while Type 2 offers a slightly stronger effect (and slightly shifted the image vertically because of the circular motion), which should go a long way to reduce aliasing artifacts and moiré as can be seen in the starburst crop. It really is quite amazing to have on-demand anti-aliasing filtering like this. Note that the AA Filter Simulator is not available in movie mode or during Bulb or HDR capture, and the full effect cannot be achieved at shutter speeds faster than 1/1000s.

Above is a real-world example of how effective the K-3 II's AA Filter Simulation feature is at reducing aliasing artifacts. Mouse over the links to see how moiré patterns in the window blinds as well as overall sharpness change with the AA filter settings.

RAW vs In-Camera JPEGs
As noted above, the Pentax K-3 II does a great job at capturing lots of fine detail in its JPEGs, but more detail can often be obtained from carefully processing RAW files, while at the same time reducing sharpening artifacts. Take a look below, to see what we mean:

In the table above, we compare an in-camera JPEG taken at base ISO using default noise reduction and sharpening (on the left) to the matching RAW file converted with Adobe Camera Raw 9.1 using default noise reduction with some strong but tight unsharp masking applied in Photoshop (300%, radius of 0.3 pixels, and a threshold of 0).

As is usually the case, Adobe Camera Raw delivers finer detail than the camera's processing, and its light default noise reduction does better with our difficult red-leaf swatch, even resolving some of its thread pattern which the camera mostly blurred away as noise. ACR also did a better job with color, rendering the pink fabric closer to reality instead of the more magenta interpretation of the camera. Adobe Camera Raw also produced finer detail in the mosaic, but left behind more noise, as seen in flatter areas such as in the bottle and background in the first pair of crops. Overall, though, the Pentax K-3 II does a very good job with its JPEGs, but as is usually the case you can extract even more detail (with more accurate color and fewer sharpening artifacts) with a good RAW converter.

ISO & Noise Performance
Very good handling of noise versus detail in JPEGs to ISO 3200.

The Pentax K-3 II's images are very clean and detailed from ISO 100 through 800, with very low chroma noise and just a touch of luma noise becoming more visible in the shadows and darker midtones as ISO increases. Detail is still very good at ISO 1600, with a tight film-like noise "grain", low chroma noise and very little fine detail lost to noise reduction (except in reds). At ISO 3200, there's increased blurring and more visible noise "grain" particularly in the shadows, but fine detail is still quite good, though some minor chroma noise can be seen in darker hair and shadows. ISO 6400 shows stronger luminance and chrominance noise as well as a slight speckled effect in flat areas, though there's still a fair amount of usable detail left. Image quality at ISO 12,800 and above falls off quickly, though, with much stronger luminance noise and speckling, and much less detail than at lower sensitivity levels. Chroma noise in the form of yellow and purple blotches becomes an issue at ISOs 25,600 and 51,200, and overall color balance shifts toward green as well, particularly at the highest ISO.

Overall, though, high ISO noise performance is excellent for a 24-megapixel APS-C camera and competitive with its closest rival, the Nikon D7200, except in low-contrast reds at higher ISOs.

Note that these images were shot using the Pentax K-3 II "Auto" noise reduction setting. The Pentax K-3 II offers an unusually flexible amount of control over noise reduction applied to its JPEGs. In addition to "Auto", you can adjust how much NR is applied ("Off", "Low", "Medium" or "High") at all ISOs, or you can select "Custom" which allows you to choose from the same four options at each ISO sensitivity setting (in whole EV increments). Of course, the impact of noise and detail loss are highly dependent on the size the photos are printed at, and pixel-peeping on-screen has surprisingly little relationship to how the images look when printed: See the Print Quality section below for recommended maximum print sizes at each ISO.

Extremes: Sunlit, dynamic range, and low light tests
Good highlight and excellent shadow detail. Very good low-light performance, capable of capturing bright images in near darkness.

Sunlight:
The Pentax K-3 II handled the deliberately harsh lighting well in the above test. Though default contrast is quite high, highlight and especially shadow detail are very good. The +0.7 EV exposure did the best job here, as we thought +0.3 and 0 EV were too dim in the face. Some highlights were blown in the mannequin's shirt and bright flowers at +0.7 EV, though, however very good detail was preserved in the shadows with relatively low levels of noise. Note that these shots were captured with the Pentax K-3 II's D-Range control set to "Off."

Because digital cameras are more like slide film than negative film (in that they tend to have a more limited tonal range), we test them in the harshest situations to see how they handle scenes with bright highlights and dark shadows, as well as what kind of sensitivity they have in low light. The shot above is designed to mimic the very harsh, contrasty effect of direct noonday sunlight, a very tough challenge for most digital cameras. (You can read details of this test here. In actual shooting conditions, be sure to use fill flash in situations like the one shown here; it's better to shoot in open shade whenever possible.)

D-Range Settings
The Pentax K-3 II offers four Shadow Correction levels (Auto, Low, Medium and High, plus Off) as well as two Highlight Correction levels (Auto and On, plus Off). As the name implies, Shadow Correction works to raise shadow levels while attempting to keep highlights and midtones as they are, and inversely, Highlight Correction attempts to reduce highlights without darkening shadows and midtones. Both can be used simultaneously. See the images below to see their effect on our high-contrast "Sunlit" Portrait test shot.

Mouse over the links to see how the various settings for D-Range affects our "Sunlit" Portrait shot, and click on a link to get to the full-res image. (The effect can be a little subtle in shots like those above, so we decided to use a mouse-over to better show how each setting compares to Off.)

Shadow Correction. Above, we see a progressive lightening of shadows and midtones as the Shadow Correction setting is increased, with only a small impact to highlights. And in this case, the Auto setting produced results very similar to the manual Low setting. If you look closely at the shadow detail, you will notice an increase in noise as the setting is turned higher, but that's to be expected and noise levels are still pretty low.

Highlight Correction. Highlight Correction worked as expected when highlights are blown, with On and Auto producing virtually identical results here (compare Highlight On or Highlight Auto to D-Range Off), toning highlights down to protect them while keeping shadows and midtones roughly the same. Note that Highlight Correction is not available at ISOs below 200, so this series was shot at ISO 200.

Here are the results of the available D-Range settings with our Far-field shot. Again, we see a lightening of shadows as the Shadow Correction setting is increased with Auto producing results similar to the Low setting. There is a slight reduction in highlights with Highlight Correction On, though this time the Auto setting produced results similar to Off, as few highlights were blown to begin with.

HDR Capture
The Pentax K-3 II has a High Dynamic Range (HDR) capture mode where the camera takes three images (underexposed, normal, and overexposed) in quick succession and combines them in-camera into one image. If performed properly, this method should result in much higher dynamic range, without the additional noise penalty that comes with boosting sensitivity or lightening shadows. (In fact, it can reduce shadow noise by combining shadows from the overexposed shot.)

There are four HDR settings available: Auto, and HDR 1/2/3 providing three blend settings, and each setting has three possible exposure ranges (±1 EV, ±2 EV (default), and ±3 EV). There's also an optional Auto Align feature for use when shooting without a tripod, which is enabled by default on the K-3 II.

Mouse-over the links above to compare thumbnails, and click on them to access full-resolution versions.

The Auto setting worked reasonably well on our Far-field test shot, reducing highlights and bringing out shadow detail while maintaining a natural, non-HDR look. HDR 1 mode produced a relatively realistic image though with an obvious HDR-ish look, HDR 2 produced a stronger effect and HDR 3 resulted in a very unnatural, almost cartoonish image. As with most HDR systems there is a slight focal-length crop with Auto Align active, and watch out for ghosting that can occur when subjects move between exposures.

Interestingly, the K3 supported RAW files in HDR mode, bundling the individual captures into one large file to be processed later by their Digital Camera Utility software which can blend or extract the separate RAW files. However, RAW file support for HDR mode appears to have been removed on the K3 II (but can be easily achieved using individual files and exposure bracketing.)

Dynamic Range Analysis (RAW mode)
While we once performed our own dynamic range measurements based on in-camera JPEGs as well as converted RAW images (when the camera was supported by Adobe Camera Raw), we've switched to using DxO Labs' results from their DxOMark website. As technology advanced, the dynamic range of modern high-end cameras in some cases exceeded the range of the Stouffer T4110 density scale that we used for our own measurements. DxO's approach based on RAW data before demosaicing is also more revealing, because it measures the fundamental dynamic range of the sensor, irrespective of whatever processing is applied to JPEGs, or to RAW data by off-the-shelf conversion software.

In the following, we use DxO's "Print" dynamic range results, which are scaled based on camera resolution. As the name suggests, this scaling corresponds to the situation in which you print at a given size, regardless of how many megapixels the camera might have. (In other words, if you've decided to make a 13x19 inch print, that's the size you're printing, whether the camera's resolution is 16 or 300 megapixels.) For the technically-minded, you can find a discussion of the reasoning behind this here on the DxOMark website. Also note that DxO Labs uses a signal-to-noise (SNR) threshold of 1 when defining the lower boundary of acceptable luminance noise in their dynamic range measurements, which corresponds to the "Low Quality" threshold of the Imatest software we used to use for this measurement.

Here we decided to compare the Pentax K-3 II to the Canon 70D, and to the Nikon D7200, which all currently sell for about US$1,000 body-only. (And in case you're wondering, the K-3 II produced very similar results to its predecessor, the K-3, with negligible improvements.) You can always compare to other models on dxomark.com.

As you can see from the above graph (click for a larger image) comparing the Pentax K-3 II's normalized dynamic range to two competitors, the K-3 II's dynamic range isn't quite as good as its closest rival, the Nikon D7200, particularly at low to moderate ISOs, but it's still very good, ranging from a maximum of 13.6 EV at base ISO down to 5.4 EV at maximum ISO. At base ISO, the D7200 managed 14.6 EV, about a full stop better than the K-3 II, and the D7200 continued to do better except at its highest ISO, where they are roughly matched.

The Pentax K-3 II's dynamic range is however significantly better than the Canon 70D's at lower ISOs, offering just over a 2 EV advantage at base ISO. At higher ISOs, the two cameras perform similarly, to the point where differences in dynamic range may be difficult to distinguish in real-world images.

Click here to visit the DxOMark page for the Pentax K-3 II for more of their test results and additional comparisons.

Low Light. The Pentax K-3 II performed well in terms of image quality in our low-light tests, capturing clean, well-exposed images at the lowest light level (1/16 foot-candle) with the lowest sensitivity setting (ISO 100). As you'd expect, noise is higher at ISO 3200 but it appears well-controlled and fairly fine-grained. Unsurprisingly, the maximum ISO of 51,200 is quite noisy with noticeably less detail, and is best avoided except for small prints and in emergencies.

Color balance with Auto white balance was quite good which isn't always the case, with just a slightly cool bias that becomes cooler as light levels drop. At the highest ISO tested (51,200), though, overall color balance shifts towards green.

We did not detect any significant issues with hot pixels or heat blooming, and only very minor horizontal banding (fixed pattern noise) can be seen at the highest ISO with almost none detectable at base ISO even in very deep shadows.

The Pentax K-3 II's phase-detection autofocus system was able to focus on our test subject down to below the 1/16 foot-candle light level using an f/2.8 lens with its AF assist light turned off, which is excellent. And it was able to focus in complete darkness with the AF assist lamp enabled, however that will obviously vary depending on the subject and distance. Unfortunately the K-3 II's autofocus struggled in Live View mode in low light, only able to focus down to just above the 1/2 foot-candle level in our tests.

(Keep in mind that the longer shutter speeds here demand the use of a tripod to prevent any blurring from camera movement. A useful trick is to just prop the camera on a convenient surface, and use its self-timer to release the shutter. This avoids any jiggling from your finger pressing the shutter button, and can work quite well when you don't have a tripod handy.)

How bright is this? The one foot-candle light level that this test begins at roughly corresponds to the brightness of typical city street-lighting at night. Cameras performing well at that level should be able to snap good-looking photos of street-lit scenes.

NOTE: This low light test is conducted with a stationary subject, and the camera mounted on a sturdy tripod. Most digital cameras will fail miserably when faced with a moving subject in dim lighting. (For example, a child's ballet recital or a holiday pageant in a gymnasium.) Digital SLRs like the Pentax K-3 II do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects.

Print Quality
Very nice 30 x 40 inch prints up to ISO 200; a good 11 x 14 inch print at ISO 3200; a usable 4 x 6 at ISO 12,800.

ISO 100 and 200 prints look practically indistinguishable from one another, and therefore both ISOs print very nicely up to 30 x 40 inches. Thanks to its 24-megapixel sensor and lack of an optical low-pass filter, the prints here looks fantastic with tons of crisp detail. You're really only limited in print size by how much you're willing to push the sensor's resolving power. Colors are also very vibrant, though we do see a noticeable shift towards magenta in our pink fabric swatch, which we've found is typical of Pentax cameras.

ISO 400 images look very similar, but with just a subtle hint of shadow noise compared to the lower ISOs. There's still a lot of sharp, fine detail, and we're comfortable calling it at 24 x 36 inches here, though we'd be okay with 30 x 40 inches for wall display or for less critical applications.

ISO 800 prints top out at 16 x 20 inches, as noise is surprisingly evident at larger print sizes. Here, 16 x 20 inch prints look the best at this sensitivity with lots of detail and well-controlled noise. A 20 x 30 inch print might be usable for less critical applications, however, as noise isn't too egregious at this size.

ISO 1600 images show a further decrease in fine detail, though detail loss is mainly in areas of lower contrast, such as our tricky red-leaf fabric. Noise is otherwise okay when limiting prints to 13 x 19 inches.

ISO 3200 prints show quite a bit of noise, to our eyes, which limits usable prints to 11 x 14 inches. Here, fine detail is decent, especially in higher contrast areas. An 8 x 10 inch print looks even better, but we're okay going a size larger.

ISO 6400 images top-out at 5 x 7 inch prints as noise has become quite problematic, impacting print quality at larger sizes. Despite the noise, colors still look vibrant.

ISO 12,800 prints just squeak by at 4 x 6 inches. Softness due to noise is certainly an issue, and printing any larger is not advisable.

ISO 25,600/51,200 images are too soft and noisy for our liking and should be avoided for prints.

The 24-megapixel Pentax K-3 II does rather well in our print quality testing, especially at lower ISOs. The camera manages to impress with large, highly detailed prints all the way up to 30 x 40 inches at ISO 100/200 -- or really however large you want to push the sensor. At mid-range ISOs, the K-3 II manages to keep noise in-check for the most part, offering a nice 13 x 19 inch print at ISO 1600 and an 11 x 14 at ISO 3200. At the top end of the ISO scale, noise becomes more of an issue and impacts print sizes noticeably. The K-3 II manages a decent 5 x 7 inch print at ISO 6400 and a usable 4 x 6 at ISO 12,800, but we'd recommend avoiding ISO 25,600-51,200 for prints, as noise and the loss of detail are quite apparent.