Pentax K-1 II Image Quality


Color

Saturation & Hue Accuracy
Vibrant default saturation with, with slightly below average hue accuracy.

In the diagram above, the squares show the original color, and the circles show the color that the camera captured. More saturated colors are located toward the periphery of the graph. Hue changes as you travel around the center. Thus, hue-accurate, highly saturated colors appear as lines radiating from the center. Click the image for a larger version.

Saturation. The Pentax K-1 II's default image tone setting of "Bright" pushes most colors by quite a bit at base ISO, especially blues, dark greens and purples. Mean saturation at ISO 100 is 118.3% or 18.3% 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. 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 K-1 II were pleasing using Manual (Custom) white balance in our test shots, however Auto white balance produced an overly pinkish appearance. Good results here. Note that the K-1 II also has a dedicated Skin Tone setting, which can improve skin tones or soften the entire image to make skin irregularities less visible. 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-1 II's mean "delta-C" color error of 6.02 after correction for saturation at ISO 100 is a bit below average for a DSLR these days (smaller numbers are better). Most noticeable were moderate shifts in orange toward yellow and cyan toward blue, with smaller shifts in 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.) Hue is "what color" the color is.

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

Sensor

Exposure and White Balance

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

Auto White Balance Strong
+0.3 EV
Multi Auto White Balance
+0.3 EV
Incandescent White Balance
+0.3 EV
Manual White Balance
+0.3 EV

The Pentax K-1 II's Auto white balance setting had a difficult time with 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). The Multi Auto WB option fared better, but the image is still too warm. Results with the Incandescent setting are actually pretty good, though, just slightly on the warm side. The Manual (Custom) setting produced pretty accurate color balance, though just a touch cool with a slightly green tint. 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-1 II required +0.3 EV exposure compensation for a good exposure, which is about average 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
Bright colors with high contrast; very good exposure accuracy.

Manual White Balance,
0 EV

The Pentax K-1 II produced a very good overall exposure without the need for exposure compensation for our "Sunlit" Portrait shot, yielding a good balance between highlights and shadows. This is much better than average in terms of exposure accuracy, however default contrast is quite high, leading to significant highlight clipping. We preferred Manual (Custom) white balance for our Portrait shot as Auto white balance produced overly pinkish skin tones, however Daylight white balance also performed well.

Native Resolution
~3,350 lines of strong detail from JPEGs, a little higher from ACR converted RAW files.

Strong detail to
~3,350 lines horizontal
Camera JPEG
Strong detail to
~3,350 lines vertical
Camera JPEG
Strong detail to
~3,450 lines horizontal
ACR processed RAW
Strong detail to
~3,450 lines vertical
ACR processed RAW

Our laboratory resolution chart reveals fairly distinct line patterns up to about 3,350 lines per picture height in the horizontal direction, and to about 3,350 lpph in the vertical direction in a best quality JPEG before lines begin to merge, though individual lines are somewhat faint and some aliasing can be seen as early as 2,200 lpph. Complete extinction of the pattern didn't occur before the 4,000 line limit of our chart in both directions. An Adobe Camera Raw conversion yielded slightly higher numbers, with individual lines that were more crisp and distinct. The ACR processed RAW image does 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
~3,450 lines of strong detail from JPEGs, about the same from converted RAW files.

Strong detail to
~3,450 lines horizontal
Camera JPEG
Strong detail to
~3,450 lines vertical
Camera JPEG
Strong detail to
~3,450 lines horizontal
ACR processed RAW
Strong detail to
~3,450 lines vertical
ACR processed RAW

The Pentax K-1 II's Pixel Shift Resolution mode (IS Off) yielded slightly higher resolution from in-camera JPEGs at about 3,450 lines both horizontally and vertically but with much crisper lines, however there were still aliasing artifacts in the form of luminance moiré patterns starting as early as 2,300 lines. Adobe Camera Raw wasn't really able to produce higher results, and interestingly, it still contained more false colors near the limits of resolution than the in-camera JPEG.

A black and white target doesn't tell the whole story, though, so click here for comparisons of single-shot to the two main Pixel Shift modes using our Still Life target at various ISOs. And see our Field Test III for real-world hand-held samples and comparisons.

Sharpness & Detail
Fairly sharp images with very good detail, though with visible edge-enhancement along high-contrast edges. Minor noise suppression visible at base ISO.

Good definition of
high-contrast elements,
though with evidence of
edge enhancement.
Subtle detail: Hair
Noise suppression tends to blur
detail in areas of subtle contrast,
though detail remains strong in
the darker parts of the hair here.

Sharpness. The Pentax K-1 II produces fairly sharp images at default settings. Edge enhancement artifacts are however visible on high-contrast subjects such as the sharpening haloes around the lettering and border in our Mas Portell bottle label above left, though we've seen far worse. Overall crispness is not bad, but JPEG images can look a touch soft at default settings. 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, with remarkably low chroma noise.

Some individual strands of hair do show aliasing artifacts in the form of "jaggies", however the K-1 II's selectable AA filter should help prevent those from occurring when enabled (AA Filter Simulation was disabled by default here for maximum resolution). 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
The Pentax K-1 II's anti-shake actuator can oscillate the sensor assembly microscopically in either a linear (Type 1) or circular (Type 2) motion during exposure, 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 settings:

As you can see above, AA Filter Simulation Type 1 blurs fine detail slightly, while Type 2 offers a slightly stronger effect, which should go a long way to reduce aliasing artifacts and moiré as can be seen, Note that the AA Filter Simulator is not available in burst mode or during Bulb or HDR capture, and the full effect cannot be achieved at shutter speeds faster than 1/1000s. Pentax has provided two AA Filter bracketing modes (Off and Type 2, or Off, Type 1 and Type 2), in case you're not sure which setting to use for a given subject matter, or want to selectively merge different exposures to reduce aliasing in specific areas in post.

RAW vs In-Camera JPEGs
As noted above, the Pentax K-1 II does a pretty good 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:

Base ISO (100)
Camera JPEG, defaults
RAW via Adobe Camera Raw

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 via DNG Converter 11.2 using default noise reduction with some moderate but tight unsharp masking applied in Photoshop (150%, 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 default processing, and its default noise reduction does a little better with our difficult red-leaf swatch, resolving a little more of the fine thread pattern. ACR also did a better job with color, rendering the pink fabric closer to reality instead of the more magenta tint from the camera. Adobe Camera Raw also produced finer detail in the mosaic, but left behind a bit more noise, as seen in flatter areas. Overall, though, the Pentax K-1 II does a good job with its JPEGs at base ISO, but as is usually the case you can extract slightly more detail (with more accurate color and fewer sharpening artifacts) with a good RAW converter.

ISO & Noise Performance
Very good high ISO performance for its class.

Noise Reduction = Auto (Default)
ISO 100 ISO 200 ISO 400
ISO 800 ISO 1600 ISO 3200
ISO 6400 ISO 12,800 ISO 25,600
ISO 51,200 ISO 102,400 ISO 204,800
ISO 409,600 ISO 819,200

The Pentax K-1 II's images are very clean and detailed from ISO 100 through 800, though there is noticeable softening in the red channel already within this range. Detail is still very good at ISOs 1600 and 3200, with a tight film-like noise "grain", low chroma noise, and very little fine detail lost to noise reduction (except in reds). ISO 6400 shows noticeably stronger luma noise but it's still fine-grained, leaving quite a bit of fine detail left. Chroma noise is still quite low, but it starts to show in the shadows. Image quality takes a larger step down at ISO 12,800, with fine detail becoming noticeably softer because of the higher noise, and chroma noise becoming visible in darker midtones. Image Quality at ISO 25,600 is not bad for such a high sensitivity, but at ISO 51,200 and above it falls off rather quickly, with much stronger luminance noise, very soft details due to strong noise reduction, as well as blotchy chroma noise. Noise becomes very obtrusive at ISOs above 102,400, and there some visible fixed pattern noise (horizontal banding) as well.

Overall, high ISO noise performance is very good for a high-res full-frame camera, though not as good as some competing models, at least in JPEGs. Noise levels do appear lower than its predecessor, but unfortunately at the expense of a slight reduction in fine detail as well as some subtle denoising artifacts. And we wonder why Pentax bothered including higher ISO settings than the original K-1, given how noisy they are.

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
High default contrast results in mediocre dynamic range in JPEGs. Excellent low-light performance, capable of capturing bright images in near darkness.

0 EV +0.3 EV +0.7 EV

Sunlight:
The Pentax K-1 II struggled with harsh lighting in the above test. Default contrast is quite high, and as a result, quite a few highlights were blown in the mannequin's white shirt and in some of the flowers, even at default (0 EV) exposure. Shadow detail is however very good, with low noise levels even in the deepest shadows. Note that these shots were captured with the Pentax K-1 II's D-Range control set to "Off."

As expected, we were easily able to recover virtually all blown highlights from the matching DNG file, indicating the dynamic range available in K-1 II RAW files is excellent.

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-1 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.

D-Range Examples

Mouse over the links to see how the various settings for D-Range affects our high-contrast Far-field 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 used a mouse-over to better show how each setting compares.)

Shadow Correction. Above, we can see a progressive lightening of shadows and midtones as the Shadow Correction setting is increased, while highlights are pretty much untouched. 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 quite low from the K-1 II.

Highlight Correction. Highlight Correction also worked as expected, with On and Auto producing virtually identical results here (compare Highlight On or Highlight Auto to D-Range Off), toning down highlights to preserve them while boosting shadows and midtones for an improved overall exposure. (Despite the brighter images, fewer highlights are blown with Highlight Correction active.) Note that Highlight Correction is not available at ISOs below 200, so these were shot at ISO 200.

HDR Capture
The Pentax K-1 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 five HDR settings available: Auto, Advanced (which applies Clarity Enhancement as well), and HDR 1/2/3 providing three blend settings. 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-1 II.

HDR Examples
HDR
ADV
HDR
Auto

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 "Sunlit"Portrait 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 with oversaturated colors, HDR 3 resulted in a very unnatural, almost cartoonish image and HDR Advanced was way over the top with strong shadows and haloing. However, keep in mind the K-1 II's HDR mode provides a decent amount of adjustments to tweak the resulting image more to your tastes.

As with most HDR systems there can be slight crop with Auto Align active as you can see above, and watch out for ghosting that can occur when images contain movement between exposures.

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.) 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.

Unfortunately, DxOMark has not yet tested the K-1 II. We'll come back and fill in this section if/when they do. In the meantime, Photons to Photos reports that the K-1 II's dynamic range is very similar to that of the K-1 below about ISO 640 (which was rated at 14.6 EV at base ISO by DxOMark). At higher ISOs, dynamic range tested significantly higher than its predecessor, although that's likely because the K-1 II applies some noise reduction to its raw data, which the K-1 did not.

LL AF:
The Pentax K-1 II's phase-detection autofocus system was able to focus on our legacy low-contrast AF target down to about -4.6 EV using an f/2.8 lens with its AF assist light turned off, which is excellent, easily beating Pentax's -3 EV spec. Interestingly, with our newer high-contrast AF target, it wasn't able to focus any lower in our tests. In Live View mode, the K-1 II was able to focus down to only -0.8 EV on our low-contrast AF target, but down to -4.1 EV on our high-contrast target, which is quite good.

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-1 II do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects.

Output Quality

Print Quality
Excellent 30 x 40 inch prints and larger up to ISO 400; a good 20 x 30 inch print at ISO 1600; a great 8 x 10 inch print at ISO 12,800.

ISO 100/200 printed images are stunning at 30 x 40 inches and larger, as large as the available resolution allows you to print at your intended viewing distance. Images exude rich, deep colors as well as nice fine detail and have a very three-dimensional pop to them. As with many Pentax cameras over the years, the pink fabric swatch of our test target is rendered a lot more magenta than it appears in reality, but that's just a typical Pentax quirk at default JPEG settings. Otherwise, the printed images here at the low ISOs are simply superb.

ISO 400 prints are also quite nice at 30 x 40 inches, with almost no trace of the sensitivity having doubled. Fine detail still abounds at this size, with virtually no noise apparent, and only a mild softening apparent in the red channel upon close inspection.

ISO 800 produces a 24 x 36 inch print that is quite good for this ISO and sensor size. Fine detail is still plentiful, with very little in the way of discernible noise at normal viewing distance. Most all contrast detail is now lost in our tricky red-leaf fabric swatch, but that's fairly normal for most cameras by this ISO, though perhaps more pronounced in this camera than some recent full-frame models. The 30 x 40 inch prints here can most certainly be used for wall display and less critical applications as well.

ISO 1600 yields a 20 x 30 inch print that still has a nice amount of "pop" for this ISO, retaining full color and much fine detail, with only minor apparent noise in flatter areas of our test target. Other than nothing much left in terms of detail in our troublesome red-leaf fabric swatch, it's quite a good print overall and deserves our "good" seal, though for your most critical printing applications here a reduction to 16 x 20 will tighten up any minor issues.

ISO 3200 delivers a 16 x 20 inch print similar to the 20 x 30 inch print above, with only similar minor issues. Printing anything larger here is not advisable, as there is simply too much in the way of noise in some areas to be considered usable. Otherwise, fine detail is still quite good, as is full color representation.

ISO 6400 prints a 13 x 19 that is quite close to passing our good rating and is considered fine for less critical applications. For solid prints at this ISO we recommend 11 x 14 inches and smaller, which still retain a reasonable amount of fine detail and full colors without becoming overly noisy.

ISO 12,800 turns in a surprisingly good 11 x 14 inch print for this ISO, and almost passes our good grade. Your mileage may vary depending on the subject, and you might be able to get away with it, but for all important printing here we recommend the 8 x 10's, which is still a nice size for such a high gain and exhibiting a tolerable amount of minor noise.

ISO 25,600 delivers a 5 x 7 inch print that is definitely in the "good" zone. Color representation here is actually pretty amazing, especially considering the often "scorched" look we see at this ISO from some models. There is a trace of minor but acceptable noise at this size.

ISO 51,200 prints a 4 x 6 that is quite close to good but not quite there. You can likely get away with it for casual use or family snapshots as needed, but otherwise we don't recommend cranking the gain this high on the K-1 Mark II.

ISO 102,400 and higher are not usable for printing purposes and are not advised.

The Pentax K-1 Mark II delivers a solid performance in the print quality department, turning in stunning images at and near base ISO, and continuing to deliver large images up to ISO 3200. We find the images to be pleasing and three dimensional for viewing, and the camera delivers in image quality as we'd expect from a good full-frame camera, though not as good as some leading competitors. Somewhat surprisingly the Mark II does not exceed any print sizes as compared to the original Mark I, despite its lower high ISO noise levels. However, it doesn't require a reduction to any sizes either, so that's a good thing. And with careful processing of RAW files or when employing Pixel Shift Resolution mode, you'll certainly be able to produce even larger prints.

 

The images above were taken from our standardized test shots. For a collection of more pictorial photos, see our Pentax K-1 II Photo Gallery .

Not sure which camera to buy? Let your eyes be the ultimate judge! Visit our Comparometer(tm) to compare images from the Pentax K-1 II with those from other cameras you may be considering. The proof is in the pictures, so let your own eyes decide which you like best!



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