Pentax K200D Exposure

Saturation & Hue Accuracy
Bright, intense colors with moderate oversaturation of strong blues, reds and greens.

Saturation. The Pentax K200D's default settings push most colors by quite a bit, especially blues, greens and some reds. Overall, images were very bright and punchy, with color that was a little over the top (in our opinion, at least) relative to other SLRs. The K200D's saturation adjustment is very effective, though, letting you adjust the color to just the saturation level you like. 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 K200D lean toward the bright side, a bit more pinkish than in real life. Some users would call this "a healthy glow", others may find it a little ruddy. 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 K200D showed a few color shifts relative to the correct mathematical translation of colors in its subjects, but had pretty good accuracy overall. Most noticeable was a shift in reds toward orange, orange toward yellow, and yellow toward green, with some shifts in cyans and blues as well. Hue is "what color" the color is.

Saturation Adjustment
The Pentax K200D has a total of nine saturation settings available, four above and four below the default saturation. The adjustment is quite effective, and the fine steps between settings mean you can program the camera to just the level of saturation you prefer. Adjusting saturation does seem to impact contrast a bit, so you may want to tweak both simultaneously.

The table above shows results with the default as well as the two extreme saturation settings, for both our previous and current Outdoor Portrait scenes. Click on any thumbnail above, then click again to see the full-sized image.

Exposure and White Balance

Indoors, incandescent lighting
Very warm results with Auto, slightly cool with Incandescent, but good color with Manual white balance setting. No exposure compensation required.

Indoors, under normal household incandescent lighting, color balance was very warm with the Auto white balance setting, resulting in a strong orange cast. Results with the Incandescent setting were a bit on the cool side, with a slightly bluish cast. The Manual setting was the most neutral and accurate. The Pentax K200D required less exposure compensation than most cameras for this shot, the images above having been shot with 0 EV of compensation. Overall color with the Manual white balance setting looks quite good, though the blue flowers appear slightly purple. (Many digital cameras reproduce these flowers with a more purplish tint, so the Pentax K200D actually did a little better than average in that regard.) 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 overall, though a tendency toward a warm cast and slightly high contrast under harsh lighting. Much better than average exposure accuracy.

Outdoors, the Pentax K200D tended toward a warmer color balance, though overall color was pretty good. The K200D performed much better than average in terms of exposure, not requiring any exposure compensation for the "Sunlit" portrait above. (We're accustomed to having to use about +1.0 EV exposure compensation for that shot.) The far-field shot of the house came out a little overexposed at the K200D's default exposure setting, but still better than average. The K200D's default contrast is a little high, producing a few washed-out highlights and dark shadows under the deliberately harsh lighting, but again, the K200D did better than average here.

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

Resolution
High resolution, 1,500 ~1,600 lines of strong detail from in-camera JPEG, about the same from processed RAW file.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,600 lines per picture height horizontally, and about 1,500 lines in the vertical direction. Extinction of the pattern occurred at around 2,200 lines in both directions. When processing the K200D's DNG files using Adobe Camera Raw (ACR, for short), we got similar results. 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 Mapping Errors
While they're at a pretty low level, and would be hard to find in any natural image, we feel we need to mention some minor pixel-mapping errors we saw in some of the K200D's images. The crops above (shown at 200%) show sections of our Multi target pattern. The small red and green dots are places where data from a neighboring good pixel has been substituted for a bad one on the K200D's sensor array. All camera companies do this, it's essentially impossible to make a 100% defect-free sensor chip at these sizes. The trick in doing pixel substitution is to not just grab an adjacent pixel, but to instead look at what's going on in the picture data surrounding that point and make the substitution in such a way that the result is invisible. That gets pretty difficult with such radically fine, high-contrast detail as is found on our Multi target. In more normal images, where tone or color doesn't vary quite this abruptly, you'd probably be hard-pressed to see this effect at all.

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

Sharpness & Detail
Fairly sharp images overall, though slightly high default sharpening leads to visible edge-enhancement artifacts on high-contrast subjects. Some noise suppression visible in the shadows.

Sharpness. The Pentax K200D's default sharpening and contrast is a little on the high side, leading to some visible edge enhancement artifacts as well as more visible noise, as shown in the crop above left. Edge enhancement creates the illusion of sharpness by enhancing colors and tones right at the edge of a rapid transition in color or tone.

Detail. The crop above right shows some noise suppression in the darkest areas of the mannequin's hair, where a few individual strands are blurred together in the darker areas. The camera's overall response here is better than average, though. 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.

RAW vs In-Camera JPEGs
As noted above, the Pentax K200D is a little heavy-handed when applying sharpening at its default settings, leading to visible sharpening artifacts in camera JPEGs. A little more detail without as many artifacts can be obtained from carefully processing RAW files. Take a look below, to see what we mean:

In the table above, mousing over a link at the bottom will load the corresponding crop in the area above. Examples consist of an in-camera Fine JPEG and a RAW file processed through Adobe Camera Raw version 4.4.1, then sharpened in Photoshop. (For the Pentax K200D's images, I found best results with fairly strong but tight 500% unsharp masking with an 0.3 pixel radius.)

Note: ACR renders colors somewhat differently than either the K200D or (most likely) the Pentax software, so the greens in the trees are rather different. There's no mistaking the increase in detail and reduction in artifacts though, regardless of changes in color or tone. We were unable to load the Pentax imaging software on our computers, so don't have a sample processed with it to show you here.

ISO & Noise Performance
Low noise at the normal sensitivity settings, with very good results to ISO 400. However, big jumps in noise at the highest settings.

The Pentax K200D produced low noise at its lower sensitivity settings of ISO 100 and 200. Noise is still well controlled at ISO 400, with good detail. At ISO 800, we start to see some loss of detail as well as noise reduction artifacts. Chroma noise starts to become readily apparent in darker tones and shadows, however fine detail is still strong as the noise "grain" pattern remains fairly tight. ISO 1,600 is of course worse, with increased blurring and more obvious chroma noise blotches, as the K200D's noise reduction attempts to hide the increase in noise. See the Print Quality section below, to find out what the recommended maximum size print is at each ISO setting.

Extremes: Sunlit and low-light tests
High resolution with strong overall detail, but slightly high contrast with strong highlights. Fairly good low-light performance, capable of capturing bright images under average city street lighting, and much darker conditions with manual intervention (inconsistent exposure and some focusing issues at the darkest levels).

Sunlight. The Pentax K200D produced slightly high contrast with some washed-out highlights and deep shadows under the harsh lighting of the test above, but performed better than most in this regard. Shadow detail is pretty good, despite some minor image noise. Our previous outdoor portrait with Marti looked best at default exposure (no compensation). Some areas look a little hot, but Marti's face was a bit too dim at -0.3 EV, and too bright at +0.3 EV. Our new outdoor target required + 0.7 EV exposure compensation for a reasonably bright face. Be sure to use fill flash in situations like the one shown above; it's better to shoot in the shade when possible.

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.)

Contrast Adjustment
We really like it when a camera gives us the ability to adjust contrast and saturation to our liking. It's even better when those adjustments cover a useful range, in steps small enough to allow for precise tweaks. Just as with its saturation adjustment, the Pentax K200D's contrast setting meets both challenges.

At its lowest contrast setting, the K200D did a pretty good job of preserving highlight detail, maintaining fairly natural-looking (if a bit pink) skin tones, and holding nice detail in the shadows. The lowest contrast setting did produce some odd saturation breaks in Marti's face, though, with some of the darker parts having very low saturation. The K200D captures good color outdoors, though again, just slightly on the warm side. Overall, very good results here, but there should be less interaction between contrast and saturation than we're seeing.

The series of shots above shows results with different contrast adjustment settings. While you can see the extremes, it's hard to really evaluate contrast on small thumbnails like these, click on any thumbnail to go to the full-size image. The Pentax K200D's contrast adjustment worked well, however it did have a strong effect on color saturation. Contrast and saturation are actually fairly closely coupled, so this unfortunately is not unusual. It does reduce the usefulness of the feature, though.

Pentax's Expanded Dynamic Range: a work in progress?
It seems like every SLR manufacturer is offering an "expanded" dynamic range mode these days, and Pentax has now joined the fray with the K200D. It should be noted, though, that these dynamic range optimization modes do nothing to increase the fundamental dynamic range of the camera; that's purely a factor of the sensor and associated electronics. What it does is attempt to optimize use of the available dynamic range, pulling some of the extreme tonal values into the visible range.

The three shots above show the results with Pentax's D-Range Off at default exposure, On at default exposure, and On with +0.3EV compensation. The shots were captured in rapid succession, but you'll notice that minor movements by Marti mean that the shots aren't absolutely identical. As you can see from the crops, the middle crop does retain highlights better, but shadows are darker (and noisier), so we're not sure what the value of Pentax's system is in this case. It almost seems as if exposure has been lowered, and, because expanded D-Range requires an ISO boost to 200, increased noise cannot be avoided. The shot on the right shows Expanded D-Range with +0.3 EV exposure compensation, bringing the shadows up to about the same level as without Expanded DR, but then the highlights in the flowers are blown-out again, so we don't see the point, at least in this shot. See the User Report for a more successful example.

Low light. The Pentax K200D performed reasonably well on the low-light test, capturing usable images at the lowest light level with the lowest sensitivity setting (ISO 100). Images are a little dim at the lower light levels though. This appears to be an issue with the K200D's low light metering, as one would expect the exposure duration to double for each decrease in light level in the table above, as the aperture is constant. Where it fails to double, the image is dim. You can, however always add exposure compensation or use manual mode to work around the K200D's low-light metering limitation, though it may take some experimentation to get the exposure correct. (The lab guys gave us quite an earful about the K200D's metering at low light levels, saying it was pretty much useless because it was so inconsistent. The only thing that worked for them was to shoot, look at the resulting image, make an adjustment, and then shoot again.)

As expected, noise increases as ISO goes up and light levels go down, but remains fairly low, even at higher sensitivities. There are no signs of banding, but there are some hot pixels evident at lower light levels. Color balance looked very good with the Auto white balance setting. The camera's autofocus system was able to focus on the subject almost down to the 1/8 foot-candle light level unassisted, which matches the exposure system well, although here again, the lab reported inconsistent behavior, and ended up shooting the low-light exposure series with the camera set to manual focus. (The Pentax K200D does have an autofocus-assist light, but it uses the camera's flash tube as the illuminator, and so requires the flash system to be engaged for it to work.) 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 K200D do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects.

Print Quality
Good print quality, very bright color (perhaps too much so for some), sharp 13 x 19-inch prints at low ISOs. Chroma noise at high ISOs limits print sizes to 8x10 inches at ISO 800, but subject detail is better preserved than in many low-end SLRs.

The Pentax K200D's printed output was pretty good, with 13x19 inch prints looking pretty crisp, very usable for table display, even under pretty close inspection. That was about the limit, though; going to 16x20 inches resulted in fairly soft images, usable for wall display, but not standing up to any sort of close viewing.

We liked some of the K200D's high-ISO characteristics quite a bit, others less so: The luminance noise has a nice character, quite fine-grained, and Pentax has managed to avoid losing lots of subtle subject detail to the noise-suppression processing. This is offset somewhat, though, by the higher-than-average chroma noise in the K200D's images.

At ISO 1,600, 8x10 inch prints are really the limit for clean output, although at that size, you'll see quite a bit of chroma noise in the shadows. At 5x7 inches, you'll still see the chroma noise, but it isn't as apparent. ISO 800 shots are a lot cleaner, and are about the most that we'd count on for routine 8x10 inch printing: You'll still see chroma noise in the shadows at that size and ISO setting, but it isn't terrible. At ISO 400, you can print as large as 11x14 inches or so without trouble.

Color-wise, the Pentax K200D's images are very vibrant, blues and pinks are especially intense. Interestingly, while the K200D's color handling really seemed a bit overdone to us when we were looking at its images on-screen, the colors moderated a bit when printed out, resulting in color that was still bright, but more believable than we'd expected: Overall, we think most consumers will be pleased with the K200D's color handling.

Testing hundreds of digital cameras, we've found that you can only tell just so much about a camera's image quality by viewing its images on-screen. Ultimately, there's no substitute for printing a lot of images and examining them closely. For this reason, we now routinely print sample images from the cameras we test on our Canon Pro9000 studio printer, and on the Canon iP5200 here in the office. (See the Canon Pixma Pro9000 review for details on that model.)