Digital Cameras - Casio Exilim EX-Z3 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, ISO setting, compression setting, etc. Rather than clutter the page below with *all* that detail, we're posting the Thumber index so only those interested in the 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 EX-Z3 had a little trouble with the harsh sunlight.
The shot at right was taken with a +0.3 EV exposure compensation adjustment, which brightened the midtones slightly. I would have liked to go further, but any additional exposure boost resulted in completely losing the highlights on Marti's shirt. I chose the Auto white balance as the most accurate overall, though it's just slightly magenta. The Daylight setting produced similar results, but the Manual setting was just a little warm.
Skin tones are pretty good, though a hint magenta, but the blue flowers in the bouquet are quite dark. (This is a very difficult blue for many digicams to get right, and are actually a light navy blue.) The strong yellows and reds are slightly faded and washed out, and the greens are a bit dark as well. Resolution is high, with a lot of fine detail visible throughout the frame, even in the shadows. Details are also sharp, and image noise the shadows is moderate.
One odd thing I noticed though, is that the white shirt has some strange, barely visible grayish flecks in it, in a sort of a crosshatched pattern. (To make them clearly visible, open an image in Photoshop(tm), access the "levels" control, and push the midtone slider all the way up to the highlight end of the scale.) They're not too obtrusive, but still definitely shouldn't be there.
To view the entire exposure series from -0.3 to +1.0 EV, see files Z3OUTAM1.HTM through Z3OUTP3.HTM on the thumbnail index page.
Slight distortion from the lens, but good color and resolution.
Overall results are similar to the wider shot above, in terms of color and exposure. However, I noticed a bluish area around Marti's right eye. The Z3's 3x zoom lens just slightly distorts Marti's features, making her face a bit more rounded in appearance than it actually is. (I'm a little puzzled by this, as the 105mm focal length should be plenty long enough to avoid this sort of minor distortion.) Detail is stronger in this shot, with better definition in Marti's face and hair. The shot at right was again taken with a +0.3 EV exposure compensation adjustment, which produced bright midtones, but blew the strong highlights in Marti's shirt collar. Shadow detail is moderate, with a moderate level of noise. There's also an odd artifact under Marti's right eye (on the left in the image), which looks a little bit like lens flare, but I'm puzzled as to where it could be coming from, as there weren't any bright light sources striking the lens directly when I shot this.
To view the entire exposure series from -0.3 to +1.3 EV, see files Z3FACM1.HTM through Z3FACP4.HTM on the thumbnail index page.
Good intensity and coverage with the built-in flash, with pretty good color.
The Z3's built-in flash illuminated the subject quite well, even at the default exposure setting. Coverage and exposure are both good, which is fortunate since the Z3's exposure compensation adjustment doesn't seem to affect the flash exposure at all. (The shot at -0.3 EV looks very similar to the shot at +1.3 EV.) The background incandescent lighting results in a magenta cast on the back wall, but color is good, although slightly muted, on Marti and the flowers.
To view the entire exposure series from -0.3 to +1.3 EV, see files Z3INFM1.HTM through Z3INFP4.HTM on the thumbnail index page.
Problems in Auto and Incandescent white balance modes, but good color with the Manual option, and good exposure.
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, And the Z3's Auto white balance option had a lot of trouble with it. The Z3's Manual white balance produced the best color here, leaving in just enough of a warm cast to convey some of the warmth of the original lighting, without overpowering the image. The Incandescent setting was somewhere between the other two, leaving a bit more warmth in the image than I'd prefer. Marti's skin tone looks pretty good with the Manual setting, but the blue flowers came out very dark and purplish, somewhat to be expected, given the light source. I found the best exposure with a +1.0 EV exposure compensation adjustment, which just barely blows the highlights on Marti's shoulder.
Good overall color and moderate detail, but very soft corners.
Both the Z3's Auto and Daylight white balance settings resulted in warm color balances here, but, the Manual setting produced good, nearly accurate results. Resolution is fairly high overall, with good detail in the tree limbs above the roof, though the shrubbery in front of the house shows less definition. The corners of the image are very soft though, the same result as I found with the Pentax Optio S, which uses the same lens. (The Z3's image is sharper overall though, apparently due to a better in-camera sharpening algorithm.)
Good resolution and detail, though limited dynamic range and a lot of softness in the corners.
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 Z3 performed fairly well. The tree limbs over the roof and fine foliage in front of the house show pretty good detail, with good definition in the leaf patterns. Details are sharp throughout most of the frame, although the two left corners are quite soft. (Not as badly so as in the House poster test above though.) The camera loses all but the strongest details in the bright white paint surrounding the bay window, which is a trouble spot for many digicams. Detail is moderate in the shadow area above the front door, evidence of the Z3's limited dynamic range. Overall color looks good, and exposure is about right. The tables below show a standard resolution and quality series, followed by an ISO series.
Lens Zoom Range
A typical 3x 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 (3x, in this case), and at full telephoto with the digital zoom enabled. The Z3's lens is equivalent to a 35-105mm zoom on a 35mm camera. That corresponds to an average wide angle to a moderate telephoto. Following are the results at each zoom setting.
Only the Manual white balance produced good color here, but the result was pretty good, only slightly pink. Good detail.
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 Z3 fell prey to that trick, with its Auto and Daylight settings both producing warm-toned images, although the Auto was the warmest of the two. Though still slightly reddish, the Manual setting produced the best looking color overall. Skin tones there are a little reddish, but not too bad, bit the blue robe is quite dark. Resolution is high, with good detail in the embroidery of the blue robe. Exposure is just a little bright, as the yellow shirt has very hot highlights.
Very tiny macro area with good detail.
The Z3 performed well in the macro category, capturing a tiny minimum area of only 1.53 x 1.15 inches (39 x 29 millimeters). Resolution is high, with pretty good detail in the dollar bill. The coins and brooch are soft due to the very short shooting distance. Corner softness is much stronger in this shot, and extends down the entire left side of the frame. Additionally, exposure is slightly dim, but overall color is good. The Z3's flash had trouble throttling down for the macro area, and overexposed the shot. - Plan on using external lighting for close-in macro shots.
A slight overexposure with washed out color, but accurate color balance with the Manual setting.
The Z3's Auto and Daylight white balances again produced warm color balances here, while the Manual setting produced much more accurate color. The Z3 had some trouble with the exposure here, as it overexposed the shot, washing out the color swatches, and blowing the highlights. As noted, colors are a little washed out in the large color blocks, although the red and blue additive primary colors show better saturation. The shadow area of the charcoal briquettes shows moderate detail, with pretty low noise, but you'd somewhat expect that, given the overexposure. Once again though, I noticed odd crosshatched grey specks in the large areas of white.
Just enough light sensitivity for average city street lighting at night.
The Z3's full automatic exposure control and maximum exposure time of 1 second somewhat limit the camera's low-light shooting capabilities. (Note that the 1 second exposure time is only available in night shooting mode, the normal limit on shutter time is only 1/8 second.) Images were usable at the (11 lux) light level, with the ISO 100 and 200 settings. Since that's the equivalent of average city street lighting at night, the camera should work OK for city night scenes, but expect to use flash for close-up subjects that might move during the exposure. 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.
Flash Range Test
A slightly weak flash, with dim intensity at the furthest test distance.
Casio rates the Z3's flash as effective only to about 7.5 feet (2.3 meters), at the normal intensity setting. In my testing, the flash power was slightly dim at eight feet, and decreased in intensity incrementally from there. Below is the flash range series, with distances from eight to 14 feet from the target.
Pretty good resolution, 1,100 lines of "strong detail." Very high barrel distortion.
The Z3 performed about average on the "laboratory" resolution test chart for a 3 megapixel camera. It started showing artifacts in the test patterns at resolutions as low as 600 lines per picture height, in both horizontal and vertical directions. I found "strong detail" out to at least 1,050 lines vertically and 1,100 horizontally. "Extinction" of the target patterns occurred around 1,200 lines.
Optical distortion on the Z3 is rather high at the wide-angle end, where I measured approximately 1.2 percent barrel distortion. (Average is about 0.8%, still much too high, IMHO.) The telephoto end fared much better, as I measured a 0.1 percent barrel distortion. Chromatic aberration surprisingly low, as there's relatively little color around the target elements. (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's a good bit of softness in the two left-hand corners of the frame, although it didn't seem to be nearly as severe as with the House poster shot above.
Resolution Series, Wide Angle
Resolution Test, Telephoto
Viewfinder Accuracy/Flash Uniformity
Excellent accuracy from the LCD monitor, but a very tight optical viewfinder.
The Z3's optical viewfinder is very tight, showing approximately 73 percent frame accuracy at wide angle, and about 77 percent at telephoto. (Average frame coverage among cameras I've tested is 85%, still too tight, IMHO.) The LCD monitor proved much more accurate, showing about 100 percent of the final frame area at wide angle and about 99 percent at telephoto. Given that I like LCD monitors to be as close to 100 percent accuracy as possible, the Z3's LCD monitor is essentially perfect in that regard. Flash distribution is more even than most at wide angle, with just a little falloff at the corners and edges of the frame. At telephoto, flash distribution is even more uniform, but quite dim.
Z3 Test Images
Z3 "Picky Details"
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