Digital Cameras - Konica Minolta DiMAGE Z2 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!|
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 Z2 produced a good exposure, though with high contrast.
The shot at right was taken with a +0.3 EV exposure compensation adjustment and the Z2's contrast control adjusted to its "low" setting. Midtones are reasonably bright, but contrast is still a bit high. Still, eve though they're pretty bright, the highlights do hold onto some detail. I chose the Auto white balance setting for the main exposure series, as the Daylight setting had a magenta cast, and the Manual setting was much too warm.
Marti's skin tones are pretty good, but the more reddish parts of her face tend to get very red - The color saturation seems higher for reds than for other colors. The blue flowers in the bouquet are almost exactly right, just slightly darker than in real life. (Many digicams have a lot of trouble with this blue.) The strong reds and greens look good as well, although I'd say that overall saturation is a little high. Resolution is high, and detail is strong in the flower bouquet as well as in Marti's features, although there's a little loss of detail in Marti's hair from the anti-noise processing. Detail is pretty good in the shadows, though image noise is moderately high there.
All in all, a very good job, although I'd like to see the contrast adjustment control have a little more range in the low-contrast direction.
To view the entire exposure series from zero to +1.3 EV, see files Z2OUTAP0.HTM through Z2OUTAP4.HTM on the thumbnail index page.
Contrast Series: The Z2's contrast adjustment did a pretty good job of creating a more even exposure at the low setting, but it seems to affect the overall exposure quite a bit. - Ideally, dropping the contrast wouldn't affect the midtone exposure any, but in the case of the Z2, it seems to pull down the midtones along with the highlights.
Overall results are similar to the wider shot above, in terms of color and exposure, and contrast and saturation are again both somewhat high, and the Auto white balance setting here produced a slightly odd color balance (a little greenish in the house siding.) Still, midtone detail is good, and the highlights are just on the verge of blowing out. The shot at right was taken with a -0.3 EV exposure compensation adjustment, which still resulted in very bright highlights. The Z2's 10x zoom lens helps prevent any geometric distortion of Marti's features, a very important feature in close-up portraits like this. Detail and resolution are stronger in this shot, with good clarity in the details of Marti's face and hair, as well as in the more subtle textures of the house siding, but there's some noise visible in the blue channel of the image. Not bad, but not at the top of the field either.
To view the entire exposure series from -0.3 to +0.7 EV, see files Z2OUTFACAM1.HTM
through Z2OUTFACAP2.HTM on the thumbnail index page.
Indoor Portrait, Flash:
Good coverage with the built-in flash, though intensity is low at the default exposure setting. Good color with the normal flash mode.
The Z2's built-in flash performed very well here, requiring just a +0.3 EV exposure compensation adjustment to get a bright exposure. Flash coverage was even at the default exposure setting, but low in intensity. Overall color is pretty good, just slightly warm from the strong household incandescent lighting. The Z2's Slow-Sync flash mode resulted in a stronger warm cast, as the longer exposure allowed more ambient lighting in, evening-out the exposure but at the cost of a much stronger color cast.
To see the entire exposure series from -0.3 to +1.3 EV in the normal flash mode, see files Z2INFM1.HTM through Z2INFP4.HTM on the thumbnail index page.
To see the same exposure series in the Slow-Sync flash mode, see files
Z2INFSM1.HTM through Z2INFSP4.HTM on the thumbnail
Indoor Portrait, No Flash:
Excellent color with Incandescent and Manual white balance options, slightly better than average exposure accuracy.
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 Z2's Auto white balance
setting fell victim to this trap, leaving a strong warm cast. It was a
toss-up between the Manual and Incandescent
settings, as each produced slight color casts. Though slightly cool-toned,
I chose the Manual setting in the end for its better white value, and
the somewhat more natural-looking skin tones. (Although I'm very torn,
feeling that the Incandescent setting produced a color balance a bit more
representative of the color of the original scene.) The red and blue flowers
in the bouquet are a bit oversaturated, and the blue flowers are dark
and purplish as well, probably to be expected, given the light source.
The shots at right were taken with a +1.0 EV
exposure compensation adjustment, which left the highlights a little overexposed,
but gave a better-looking image overall (IMHO) than the one shots at +0.7
Pretty good color, though slightly warm, with high resolution and a lot of fine detail.
This is another shot where the best white balance setting is really a
matter of personal preference, as both the Z2's Daylight
and Manual settings produced very slight
color casts, but still good overall color. (The Auto
setting resulted in a strong reddish cast.) In the end, I chose the slightly
cool color of the Manual setting, as it appeared "cleaner" than
the slightly warm cast of the Daylight option. Resolution is high, and
detail is strong in the tree limbs and front shrubbery, as well as the
house front. (The Z2's four-megapixel CCD comes close to the limits of
this poster as a test target, even though the it was made from a 500MB
scan of a 4x5 negative shot with a tack-sharp lens.) Details are fairly
sharp throughout the majority of the frame, with slight corner softness
on the left side.
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 Z2 captures a lot of fine detail, but its image is a bit softer than those of the best four-megapixel digicam models. The leaf patterns in the shrubbery in front of the house are reasonably well-defined, and the tree limbs above the roof show pretty good detail as well, but all details are on the soft side. The camera loses detail in the strongest highlights of the bay window, a trouble spot for many digicams, but does slightly better in the shadow area above the front door. - I'd call its dynamic range "average." Color looks about right (the bricks are a little red though), and saturation is good. The table below shows a standard resolution and quality series, followed by ISO, contrast, saturation, white balance, and color series.
White Balance Series:
Lens Zoom Range
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 Z2's lens is equivalent to a 38-380mm zoom on a 35mm camera. That corresponds to a moderate wide angle to a very substantial telephoto. Following are the results at each zoom setting.
Moderate color casts with each white balance setting, due to the difficult subject. Slightly "hot" reds. Good resolution though.
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 Z2's white balance system had some difficulty
here, as each of the settings tested produced a moderate to strong color
cast. The Auto setting resulted in a very strong
warm cast, while the Daylight setting had a
moderate red tint. The Manual setting resulted
in a cooler image, with a magenta cast. Although skin tones are very red,
I chose the Daylight setting as the best of the three. The red cast turns
the blue background purple, and creates purple tints in the shadows of
the blue robe. Detail, however, is strong, and resolution is high. The
fine details of the embroidery on the blue robe, beaded necklaces, and
instrument strings are all clear. (The original data file for this poster
was only 20MB though, so the Z2 is definitely capable of showing more
detail than the poster has in it.)
A very tiny macro area with good detail in the dollar bill. Flash is blocked by the lens, however.
The Z2 performed very well in the macro category, capturing a minimum
area of only 1.43 x 1.07 inches (36 x 27 millimeters). Resolution is very
high, and detail is strong in the dollar bill. Details are soft in the
coins and brooch from the close shooting distance (not the camera's fault,
depth of field is naturally very shallow when shooting this close), and
are slightly soft in the dollar bill as well. There's a lot of softness
in the corners on the left side of the frame, a not uncommon limitation
of digicams' ultra-macro modes, caused by curvature of field in their
lenses. The position of the Z2's flash directly
above the lens results in a dark shadow in the lower portion of the frame.
"Davebox" Test Target
Good color and exposure, though contrast and saturation are high.
The Z2's Auto and Daylight
white balance settings both produced similar, warm images, while the Manual
setting produced a more accurate color balance. Exposure is pretty good,
though contrast is a bit high, and the Z2 distinguishes the subtle tonal
variations of the Q60 target well. The large color blocks look nearly
accurate, with good saturation. (The large red and blue blocks are somewhat
oversaturated, however.) The shadow area of the charcoal briquettes shows
moderate detail, with a moderate level of noise.
Good low-light performance, with good exposure and focus even at the darkest light levels. Surprisingly low noise for such long exposures, color balance is a little warm. A very usable EVF at low light levels, and one of the only true "time" exposure options I've seen on a digicam.
The Z2 produced clear, bright, usable images down to the 1/16 foot-candle (0.67 lux) limit of my test, at all four ISO settings. (At ISO 50, the exposure was somewhat dim at this lowest light level, but you could arguably still use the image.) The Z2's auto white balance system produced warm color casts under the dim lighting, with decreasing color cast as the light level increased. The Z2's Noise Reduction system does a reasonable job of suppressing image noise, though noise is still present. Compared to the results from the camera under daytime light levels though , the image noise in the long exposures shown here is really surprisingly low. The Z2's LCD/electronic viewfinder is usable at light levels a good bit darker than average, and the Z2 is also unique for having one of the only true "time" exposure modes I've seen on a digicam. (On the Z2, with the time exposure option in Manual exposure mode, you press the shutter button once to open the shutter, and again to close it. Most digicams have a Bulb mode, which requires that you hold the shutter button down to keep the shutter open.) 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: If you'd like to use a light meter to check light levels for subjects you might be interested in shooting, a light level of one foot-candle corresponds to a normal exposure of two seconds at f/2.8 and ISO 100.)
Flash Range Test
A surprisingly powerful flash, with only slight falloff at the 14 foot limit of this test.
In my testing, the Z2's flash illuminated the test target all the way out to 14 feet, without any significant decrease in intensity, and with no apparent "cheating" in the form of a quietly boosted ISO setting. (A tactic employed by many digicams these days.) Below is the flash range series, with distances from eight to 14 feet from the target.
Very good resolution, 1,200 lines of "strong detail." Low barrel distortion, moderately low chromatic aberration, good sharpness in the corners.
The Z2 performed very well on the "laboratory" resolution test chart. It started showing artifacts in the test patterns at resolutions as low as 800 lines per picture height vertically, and around 650 lines horizontally. I found "strong detail" out to at 1,200 lines in both directions. "Extinction" of the target patterns didn't occur until about 1,400 lines.
Optical distortion on the Z2 is quite a bit lower than average at the wide-angle end, where I measured approximately 0.3 percent barrel distortion. The telephoto end fared very well also, as I didn't see so much as a full pixel of pincushion or barrel distortion. Chromatic aberration is moderate, showing several pixels of color on either side of the target lines, but the color itself not being as strong as on many long-zoom cameras. (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.)
Resolution Series, Wide Angle
Resolution Test, Telephoto
Viewfinder Accuracy/Flash Uniformity
A very accurate electronic viewfinder, and nearly perfect LCD monitor.
The Z2's electronic viewfinder (EVF) is very accurate, showing 96 percent frame accuracy at wide angle, and about 97 percent at telephoto. The LCD monitor is also very accurate, showing about 99+ percent accuracy. The two displays actually use the same LCD, the difference in accuracy most likely simply being a minor difference in the cropping and/or optics as the LCD flips up into its "EVF" position. Given that I like LCD monitors to be as close to 100 percent accuracy as possible, the Z2's LCD monitor does very well here (as does the EVF, for that matter). The flash underexposed slightly at wide angle, but the light distribution was quite even, with just a little falloff in the corners of the frame. At telephoto, flash exposure is brighter and a little more uniform.
Z2 Test Images
Z2 "Picky Details"
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