Digital Cameras - Minolta DiMAGE Z1 Test Images
|I've begun including links in our reviews to a Thumber-generated index page for the test shots. The Thumber data includes a host of information on the images, including shutter speed, ISOsetting, compression setting, etc. Rather than clutter the page below with *all*that detail, we're posting the Thumber index so only those interested inthe information need wade through it!|
|Outdoor Portrait: |
The extreme tonal range of this image makes it a tough shot for many digicams, which is precisely why I set it up this way, and why I shoot it with no fill flash or reflector to open the shadows. The object is to hold both highlight and shadow detail without producing a "flat" picture with muddy colors, and the DiMAGE Z1 had just a little trouble with the harsh lighting, but overall results are still pretty good.
The shot at right was taken with a +0.7 EV exposure compensation adjustment, which brightened the midtones slightly, but lost a little more detail in the highlights than I would have liked. Still, the lesser highlights in Marti's shirt hold fairly good detail, and the overall image looks pretty good. To tone down the image, I shot with the camera's low contrast adjustment, which evened out the exposure slightly. (See below for a side-by-side comparison.) I chose the Auto white balance as the most accurate overall, though the Manual setting produced similar results. The Daylight setting resulted in a cooler, slightly blue-green image.
Skin tones are about right with the Auto white balance, although the blue flowers are a little dark with more purple in them than in real life. (This is a difficult blue for many digicams to correctly reproduce, and is actually a light navy blue with just hints of purple in real life.) Color looks nearly right throughout the rest of the frame as well, but is slightly undersaturated to my eye. Resolution is high, with a lot of fine detail visible throughout the frame, and, despite the high contrast, good detail in the shadows. Image noise is low.
To view the entire exposure series from zero to +1.0 EV, see files Z1OUTAP0.HTM through Z1OUTAP3.HTM on the thumbnail index page.
Great resolution and detail and good color, though contrast is again high with the default settings.
Overall results are similar to the wider shot above, and contrast is again somewhat high. The shot at right was taken at the default exposure, but still borders on being too bright. I also shot with the camera's low contrast setting, which created a more even exposure. (See comparison below.) The Z1's 10x zoom lens helps prevent any distortion of Marti's features, extremely beneficial in close-up shots like this. Detail is much stronger in this shot, and details are crisp throughout the frame.
To view the entire exposure series from zero to +0.7 EV, see files Z1FACAP0.HTM
through Z1FACAP2.HTM on the thumbnail index page.
Indoor Portrait, Flash:
A slight purple cast, from the combo of room lighting and the flash itself, but good overall color and intensity.
The Z1's built-in flash did a pretty good job illuminating the subject here, although it underexposed badly at the default exposure setting. (As do many digicams with this high-key subject.) I obtained the best exposure with a +1.3 EV exposure compensation adjustment, although the highlights on Marti's shirt border on being too hot. Overall color is good, but the cool tone of the flash combined with the warmth of the incandescent room lighting results in purplish tints on Marti's shirt. I also shot with the camera's Slow-Sync flash setting, finding the best results with a +0.7 EV exposure compensation adjustment. (Click here for the default exposure in Slow-Sync mode, which was just slightly dim.) The exposure is more even with the longer shutter time, though the purplish tints on the white shirt are stronger.
To view the exposure series at zero and from +1.0 through +1.7 EV, see files Z1INFP0.HTM, and Z1INFP3.HTM through Z1INFP5.HTM on the thumbnail index page.
Slight color casts with each white balance setting tested, though the most natural skin tones with the Incandescent setting.
This shot is always a very tough test of a camera's white balance capability, given the strong, yellowish color cast of the household incandescent bulbs used for the lighting. The Z1 had a little trouble here, producing color casts with each white balance setting I tested, although any of the images could be considered usable. In the end, I settled on the Manual setting as the most accurate overall, despite the somewhat cool color balance. The Auto white balance was too pinkish, and the Incandescent setting was a bit too warm for my taste. Although cool, the overall color isn't at all bad with the Manual white balance. Skin tones are just a little pale, but the blue flowers actually look pretty good, just slightly dark. The main shot was taken with a +1.0 EV exposure compensation adjustment, which is about average for this shot among the cameras I've tested.
Good resolution and detail, but slight color casts with each white balance setting tested.
The Z1's Daylight white balance produced the best overall color here, despite a slight greenish tint. Actually, all three white balances I tested had a little trouble here, producing slight color casts. The Auto setting resulted in a reddish tint, while the Manual setting produced a very noticeable cool cast. Resolution is high, as the tree limbs and front shrubbery show a good level of detail. Details are fairly sharp throughout most of the frame, although the two left corners are soft.
High resolution and good detail, but a limited dynamic range
This image is shot at infinity to test far-field lens performance. NOTE that this image cannot be directly compared to the other "house" shot, which is a poster, shot in the studio. The rendering of detail in the poster will be very different than in this shot, and color values (and even the presence or absence of leaves on the trees!) will vary in this subject as the seasons progress. In general though, you can evaluate detail in the bricks, shingles and window detail, and in the tree branches against the sky. Compression artifacts are most likely to show in the trim along the edge of the roof, in the bricks, or in the relatively "flat" areas in the windows.
This is my ultimate "resolution shot," given the infinite range of detail in a natural scene like this, and the Z1 performed quite well in that regard. The tree limbs over the roof and fine foliage in front of the house show a lot of fine detail, with pretty good definition in the leaf patterns. Details are just slightly soft throughout the frame, although the level of sharpness is consistent from corner to corner. (My interpretation of this is that the Z1's default in-camera sharpening is a little understated - The image takes unsharp masking in Photoshop(tm) pretty well, and there's surprisingly little loss of sharpness in the corners.) The camera has trouble with the bright white paint surrounding the bay window, losing practically all of the detail there, but does a bit better in the shadow area above the front door, even though the shadow there is very dark. (A long streak of bad weather meant I had to grab this shot later in the day than I usually would have, resulting in much deeper shadows than you'd normally see here.) Overall color looks good, and exposure is good as well. Overall, a nice job, marred slightly by the lost highlight detail. The table below shows a standard resolution and quality series, followed by ISO, sharpness, contrast, and color series.
Excellent 10x zoom range.
I routinely shoot this series of images to show the field of view for each camera, with the lens at full wide angle, at maximum telephoto (10x, in this case), and at full telephoto with the digital zoom enabled. The Z1's lens is equivalent to a 38-380mm zoom on a 35mm camera. That corresponds to a moderate wide angle to a pretty substantial telephoto. Following are the results at each zoom setting.
Some trouble with auto and manual white balance, but good color with the daylight setting and good overall detail and resolution.
This shot is often a tough test for digicams, as the abundance of blue in the composition frequently tricks white balance systems into producing a warm color balance. The Auto setting very much fell prey to the too-much-blue problem, producing a pronounced red cast, while the Manual setting resulted in a strong cool cast. The Daylight option proved to be the best of the lot, with just a slight greenish tinge in the final image. Skin tones are to normal, though still a bit pale. Despite the greenish color cast, the blue robe is nearly right. Resolution is high, and detail is good in the embroidery of the blue robe and red vest, as well as in the beaded necklaces.
A very small macro area with good detail, although the flash is blocked by the camera.
The Z1 performed very well in the macro category, capturing a minimum area of only 1.65 x 1.24 inches (42 x 31 millimeters). Resolution is high, with good detail in the dollar bill, as well as in the fibers of the gray background. The coins and brooch are soft due to the very short shooting distance, although detail is still fairly good in these areas as well. Corner softness is noticeable in the two left corners of the frame, although the soft coin and brooch make it difficult to evaluate image sharpness on the right side. Color balance is slightly cool, and overall exposure is a little dark, but this is an excellent job overall. The Z1's flash was blocked in the lower portion of the frame by the camera, so an alternative light source may be preferable for the closest macro shooting.
"Davebox" Test Target
Good overall exposure, almost perfectly neutral color with the Manual white balance setting, very good color.
The Z1's Manual white balance produced the most accurate color here, almost perfectly neutral. The Auto setting resulted in a slight red cast, while the Daylight setting produced a greenish image. Exposure is about right, and the Z1 has no trouble with the subtle tonal variations of the Q60 target. The large color blocks are very hue-accurate, although slightly dark. That said, the large, blue additive primary color block is just a tad oversaturated. The shadow area of the charcoal briquettes shows good detail, with fairly low noise.
Great low-light shooting, with good results even at the lowest light levels.
The DiMAGE Z1 offers a full manual exposure mode, plus a maximum shutter time of 30 seconds (with the Bulb setting). Thus, the camera performed quite well on this test. It produced clear, bright, usable images down to the 1/16 foot-candle (0.67 lux) limit of my test, with pretty good color at all four ISO settings. Color balance was sometimes a bit warm, but still good overall. The Z1's Noise Reduction system did an excellent job of suppressing excess image noise. Even at ISO 400, the noise level is really pretty low. A very nice job. The table below shows the best exposure I was able to obtain for each of a range of illumination levels. Images in this table (like all sample photos) are untouched, exactly as they came from the camera.
(Note: For reference, if you'd like to check out light levels with a light meter for common subjects you might be interested in shooting, a light level of 1 foot-candle corresponds to an exposure of 2 seconds at F/2.8 and ISO 100.)
Flash Range Test
Varying levels of intensity depending on the telephoto setting, but a bright exposure at 14 feet.
In my testing, the Z1's flash illuminated the test target all the way out to 14 feet, but the exposure was a little inconsistent as I moved out and zoomed in the camera's lens. Still, the image at 14 feet was fairly bright, and the camera didn't "cheat" by automatically boosting its ISO setting as so many do these days. Below is the flash range series, with distances from eight to 14 feet from the target.
High resolution, 1,050 lines of "strong detail." High barrel distortion at wide angle, and a lower amount at telephoto.
The Z1's 3.2-megapixel CCD performed well on the "laboratory" resolution test chart. It started showing artifacts in the test patterns at resolutions as low as 600 lines per picture height, in both horizontal and vertical directions, but I found "strong detail" out to 1,050 lines. "Extinction" of the target patterns occurred around 1,200 lines.
Optical distortion on the Z1 is slightly higher than average at the wide-angle end, where I measured approximately 0.9 percent barrel distortion. (The average is about 0.8 percent, still too high IMHO.) The telephoto end fared much better, as I found only two pixels of barrel distortion, about 0.1 percent. Chromatic aberration is fairly low, showing only faint coloration on either side of the target lines in the corners. (This distortion is visible as a very slight colored fringe around the objects at the edges of the field of view on the resolution target.) There was also only a little softness in the corners of a few shots, most notably along the left side of the frame. All in all, the Z1's lens did very well in my tests, particularly for such a long-ratio zoom.
Resolution Series, Wide Angle
Resolution Test, Telephoto
Viewfinder Accuracy/Flash Uniformity
Good accuracy from the electronic optical viewfinder, though a little bit tight.
The Z1's electronic "optical" viewfinder (EVF) is just a little tight, but still pretty accurate, showing 93 percent frame accuracy at wide angle, and about 95 percent accuracy at telephoto. Although the LCD monitor shows the same view, just on a larger screen, it proved slightly more accurate at the wide angle setting, showing about 98 percent frame accuracy. However, at telephoto, the top of the frame was cut off in the eyelevel finder, so I couldn't measure with my usual process. Given that I like LCD monitors to be as close to 100 percent accuracy as possible, the Z1's LCD monitor does a very good job in that respect, although you'll have to watch framing at the telephoto end of the range. Flash distribution is a bit uneven at wide angle, with falloff at the corners and edges of the frame. At telephoto, flash distribution is more uniform, but still has very slight falloff in the corners.
Z1 Test Images
Z1 "Picky Details"
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