Casio Exilim EX-Z1000

Color (5.83)
The Casio Z1000 faced its first challenge in the testing studio attempting to reproduce realistic colors. Historically, Exilim digital cameras have had trouble in this area, but new models come with new technology so we always hope for the best. We tested the Z1000 by snapping several well lit shots of an industry standard color chart manufactured by GretagMacbeth. The color chart has 24 tiles with different colors in each. The Casio Z1000’s pictures of the chart were uploaded into Imatest imaging software, which output the following modified chart. The outer square of each tile shows the Z1000’s color, while the vertical rectangle in the center of the tile shows the original color of the chart. The inner square of the tile shows the ideal color corrected for luminance by the software.  

If you’re having trouble distinguishing the greens from each other, check out the chart below. It shows the same information in an easier to decipher graph. The circles represent the Casio Z1000’s produced colors, while the squares represent what they should be (the ideal colors from the GretagMacbeth chart). The line tethering the two shapes shows the degree of error – the longer the line, the more inaccurate the color.  

This chart looks very similar to the one that the Casio Exilim EX-S600 produced. Many of the same colors are exaggerated, particularly the blues. The Z1000 went a little farther though and exaggerated the greens too. The two cameras’ colors also differ in their color saturation. The S600 over-saturated by 8 percent, which is typical of a compact digital camera. The Z1000 under-saturated by almost 5 percent. For its halfhearted effort, this Casio received an overall color score of 5.83, which is even worse than the S600’s 6.7. The Casio Exilim Z1000 had a mean color error of 8.39 and really shouldn’t be counted on for realistic looking pictures.

 

Still Life Scene
Below is a shot of our retro plastic still life array, captured with the Casio Exilim EX-Z1000. 

Resolution (3.48)
The Casio Exilim EX-Z1000 advertises a massive amount of resolution for a compact digital camera. With an advertised 10.1 megapixels, the Z1000’s resolution specs rival those of fancier and pricier DSLRs. But advertised pixel counts aren’t always completely reliable. To see how effective the Z1000’s 10.1 megapixels are, we took several well lit pictures of an industry standard resolution chart and loaded them into Imatest imaging software. The program analyzed all the shots, which were taken at various focal lengths and apertures, and selected the absolute sharpest shot. That shot is pictured below and was taken using an aperture of f/5.4 and a focal length of 23.7 mm.

Imatest output quantitative resolution results in terms of line widths per picture height (lw/ph), which is a theoretical measurement of how many black and white lines could fit across the frame without blurring. The Casio Exilim EX-Z1000 resolved 1606 lw/ph horizontally while under-sharpening just 0.93 percent. The camera resolved 1577 lw/ph vertically and under-sharpened slightly more, but nothing out of control, at 1.59 percent.

The Z1000’s resolution results aren’t as impressive as its specifications might indicate. In contrast, the Sony W100 resolved 1856 lw/ph horizontally and 1310 lw/ph vertically – and it only advertises 8.1 megapixels. The Canon PowerShot SD700, which advertises 6 effective megapixels, read 1907 lw/ph horizontally and 1844 lw/ph vertically. The Fujifilm FinePix F30 read 2005 lw/ph horizontally and 1786 lw/ph vertically with its 6.3-megapixel count, but used a lot more in-camera sharpening.

Overall, the actual resolution is a bit disappointing as its numbers rival results from cameras that advertise far less pixels.

Noise – Auto ISO (3.06)
The Casio Z1000 is built for point-and-shooters with its automatic modes and slim frame. It is expected that the automatic ISO function will be used often because of its audience that appreciates snapping pictures without worrying about which ISO to select and what white balance mode to choose and such. Unfortunately, the Z1000 metered our bright scene and automatically selected an ISO that produced as much noise as was found at the manual ISO 200 setting. This is too much noise and too high of a sensitivity for the light levels used in this test. Thus, the Z1000 came out with an overall automatic ISO noise score of 3.06, which is quite poor but still better than the Casio S600’s 2.1 score.

Noise – Manual ISO (5.70)
The Casio Z1000 was challenged yet again when its noise levels in the manual ISO settings were tested. This Exilim has a disappointingly short general ISO range from 80-400 with only four stops: 80, 100, 200 and 400. We tested the noise at each of these settings and ran a regression analysis to determine the overall score. Below is a chart showing the ISO sensitivities on the horizontal plane and the noise levels on the vertical plane.  

Once again, this steady curve looks familiar – like the Casio S600’s noise chart. The results differ a bit though. The Z1000’s ISO 80 setting has more noise, so it has a shorter slope as the two cameras produce about the same amount of noise at ISO 400. The Z1000 squeaked by with an overall manual ISO noise score of 5.7 compared with the S600’s 5.18 digits, but it should be kept in mind that the manual ISO selection on these models is generally short.

Low Light Performance (1.5)
This automatically oriented digital camera does not have a manual shutter speed setting to lengthen the exposure time, so shooting in low light got very interesting in the studio. The night scene mode in the Best Shot selection was used, and although it had its problems it was the best we could do. We tested the camera in lighting conditions of 60, 30, 15 and 5 lux. The 60 lux test is a fairly common light situation roughly equivalent to pulling the shades and relying on two soft lamps in the living room. The 30 lux test is like photographing in a room with a single 40-watt bulb. The 15 lux test is something like a very dim night light, with 5 lux making it hard to even find the shutter release button. Below are the images taken in this lighting.

 

The images are all under-exposed and horribly blurry too. The camera sat atop a tripod and was activated with a 20-second self-timer so as to minimize camera shake. However, it is the auto focus system to blame. When photographing the color chart in low light, the Z1000 would shoot out a constant white beam of light. Whereas most digital cameras use the beam only to focus and then turn it off prior to capture, the Z1000 kept shooting the beam even when the shutter was open – which got in the picture several times. The resultant pictures are extremely blurry and look similar to those taken by the slim Casio S600.

Despite using the night scene mode to get longer shutter speeds, the exposure time still isn’t incredibly long. The longest it could scrounge was an entire second (yes, just one) at 5 lux. Below is a chart showing the exposure time on the horizontal axis and the noise level on the vertical axis. Often, noise increases with longer exposures.

Pictures in low light are already unusable because of the poor auto focus system and resultant blurry images, but the abundant noise just adds to the evidence that the Z1000 should be banned from snapping shots in limited light.

Dynamic Range (2.0)

Cameras set their exposure for the middle of the brightness range, in order to record subjects that are neither very bright nor very dark. Most parts of most subjects, including faces and most plants and animals, fall into the medium brightness range. Dynamic range measures how much brighter or darker parts of the subject can be and still show detail in a picture. This is important, because every subject has highlights and shadows. With a camera that has poor dynamic range, the highlights look like blobs of pure white and the shadows appear as pure black.

 

We test dynamic range by photographing a Stouffer test chart. It shows a series of rectangles ranging from very bright to very dark. We analyze the images of the chart with Imatest software, which measures the number of tonal steps the camera captures. Imatest measures dynamic range at high and low quality levels, and we report both results. Dynamic range varies with a camera's ISO setting, so we test cameras throughout their range of ISOs. 

The Casio EX-Z1000 did poorly on our dynamic range test. We tested two samples of the Z1000, and both scored poorly: so poorly that we consulted with an engineer at Imatest, who is confident that our results are reliable. The Z1000 is not capable of shooting decently exposed pictures in bright light. 

The Casio Z1000 managed to start up and capture a frame in 2.61 seconds, which is typical of digital cameras with live previews. 2.61 seconds is a very long time, compared to how long most spontaneous moments last – users who hope to catch a moment of surprise - a high-five, a hug, a shout, birthday candles getting blown out and so on - better have the camera turned on before anything good happens.

 

The EX-Z1000 has four continuous shooting modes. In "Normal Speed" mode, it hits 0.7 frames per second, which is very slow, but it keeps on going as long as the shutter release is held down. In "High Speed" mode, it shoots 3 frames in less than 3/4 of a second, for a rate of 4.1 fps. It hit 4.1 fps in "Flash Cont.," with the same 3-frame burst it has in High Speed. "Zoom Cont." isn't continuous at all – it shoots a single, full-resolution, 10.1 megapixel shot and saves the full frame and a 3-megapixel crop. The wrinkle is that the user sets the region of the frame to be cropped before taking the shot.

 

What users hate most about digital cameras is the lag between the moment they press the shutter and the moment the camera gets around to actually taking the picture. Our consistent result with this Exilim was 0.18 seconds, which is much better than those of most competing cameras. It's not as good as the hulking DSLRs that the pros use to photograph sports, but it's noticeably better than many small cameras.