Testing / Performance
We use a standardized test to compare the color performance of all the cameras we review. The process involves photographing an industry-standard GretagMacbeth color target at all manual ISO settings, and running the images through Imatest software to measure color accuracy. In the chart below, the outer square represents the colors produced by the FZ7, while the vertical rectangle in the center is the ideal tone. The inner square is the ideal, corrected for luminance by Imatest.
The FZ7 over-saturated colors considerably. Perfectly accurate saturation is 100%, and the FZ7 hit 120%. This is a big boost, even among compact cameras, which are typically biased toward bright colors. The camera particularly boosted reds, oranges and pinks, a common trait of snapshot-oriented cameras, because the boost makes for appealing, if not accurate, 'skin tones.'
The mean color error in the FZ7's image is 9.56. Again, this is a high number, but it is in the direction that many users will like – toward rosy cheeks and lurid red sunsets. The drawback to all this brilliant but inaccurate color is that the images become hard to edit. It's easy to boost the colors of an accurate shot, but very hard to correct the colors of an over-saturated image.
**Still Life Scene
**Below is a shot of our still life scene captured with the Panasonic DMC-FZ7.
Click on the image above to view a full resolution version.](http://www.digitalcamerainfo.com/viewer.php?picture=FZ7-StillLife-LG.jpg)
Resolution / Sharpness*(4.87)*
The FZ7's 6-megapixel sensor and Vario-Elmarit lens should be able to deliver sharp images. We tested the resolution of the optical system by photographing a resolution chart and running the images through Imatest software. Imatest reports results in line widths per picture height – the number of alternating black-and-white lines the camera could theoretically show clearly. Imatest not only indicates how many lines the camera could show, but also how much sharpening the camera's digital image processor has done.
Click on the above chart to view a full res version](http://www.digitalcamerainfo.com/viewer.php?picture=FZ7-ResCH-LG.jpg )
The FZ7 delivered scores of 1912 lw/ph horizontally and 1497 vertically. These are very good numbers for a compact super-zoom. The FZ7 over-sharpens by 21.3% horizontally and 9.87% vertically. This amount of sharpening is typical of compact cameras, though the FZ7 is unusual in how different the horizontal and vertical figures are. The drawback of this amount of sharpening in camera is that it limits the amount of post-processing possible – a sharpened image starts to show odd "halo" effects and other problems when it is re-sharpened.
Noise – Auto ISO*(1.72)*
When we tested noise in the auto ISO setting, the FZ7 delivered results comparable to ISO 150 on the camera. The test was done in very bright lighting, so we expected results closer to ISO 80 – the setting we would have manually set when photographing in that light. This resulted in excess noise for the lighting setup and led to the low overall score.
**Noise – Manual ISO ***(3.87)*
The FZ7 has manual ISO settings of 80, 100, 200 and 400. We measured noise at each available ISO setting. Though we found that its noise performance does not deteriorate enormously as the ISO setting rises, it is higher than typical throughout the range.
The graph above shows that ISO 80 and 100 are very similar, and the biggest jump is between 100 and 200. The jump from 200 to 400 is just slightly smaller.
Low Light Performance*(7.0)*
To test the Panasonic FZ7’s low light performance, we took a series of exposures at various light levels. Cameras are tested at 60, 30, 15, and 5 lux, to approximate typical low light conditions. 60 lux is similar to a moderately lit bedroom, while 30 lux is about the same amount of illumination as a 40 watt lightbulb. 15 and 5 lux are near darkness and force the camera to prolong exposures to achieve proper tonal levels. Images for our low light test are captured with the flash off, set to the camera’s highest manual ISO setting.
The FZ7 has better noise control in long exposures than many competing cameras. You can see the noise graph below is actually pretty flat. This illustrates the consistency maintained by the camera as exposures are increased.
The main low light tests were performed with the camera in manual mode, which allows ISO settings of up to 400. We also ran our tests with the FZ7 in Low Light mode, which allows ISO settings of up to 1600, but does not allow manual exposure or white balance control. At ISO 800, both noise and color accuracy took a turn for the worse. A big part of the problem is the very poor performance of auto white balance in low light.
Dynamic Range*(6.25) *
We have begun testing dynamic range using Imatest software, the same program we use for color, resolution and noise testing. In a darkened room, we photograph a backlit film step chart, which shows a row of rectangles that range from fairly transparent to very dark. The chart shows more than 13 stops of exposure, which is a wider range than conventional cameras can capture. Imatest measures how much of the range the camera can show, at various levels of quality. Note that this test sets up an ideal situation for measuring dynamic range, so users shouldn't expect to achieve the same dynamic range in real-life shooting. The data should be used as a guide to gauge the camera's relative performance.
As you can see in the graph above, the FZ7 displayed essentially the same dynamic range at ISO 80 and 100 – ISO 100 looked 0.1 stop better than ISO 80 at low quality, and 80 looked 0.01 stop better at high quality. It's unlikely that those differences amount to useful data. What's clear is that the FZ7 loses a bit more than a stop of dynamic range for each stop increase in ISO, and that there is a significant difference between 100 and 200. In more advanced cameras, it's common to see 200 more like the quality of 100, with the significant drop delayed until 400.
The FZ7 touts ISO settings of 800 and 1600, but they are available only in High Sensitivity (an automatic scene mode).
Speed / Timing
Start-up to First Shot*(6.4)*
The FZ7 has to extend its lens when it starts up, so it is by no means a speed demon when it comes to awakening. Our best time from flipping the switch to capturing an image was 3.6 seconds.
Shot to Shot Time*(9.69)*
The FZ7 has three burst modes: High, Low and Continuous. We tested all of them with a 32MB SanDisk SD card, shooting at full resolution JEPG Fine files. In High, the FZ7 took 7 shots in 2.12 seconds, for an average 3.3 frames per second – better than the 3 fps the manual promises. In Low, we got 7 shots in 2.91 seconds, for about 2.4 frames per second. After shooting 7 images in Low or High, it takes the FZ7 about 14 seconds to finish writing the images to memory. Continuous is supposed to allow continuous shooting until the memory is full. It did this, in a way, but not how we expected. The first 8 frames went off at better than 2.5 frames per second, but then the speed dropped to about 1 frame every 2 seconds. We had expected, and would have preferred, a slower rate that was steady throughout the length of the burst.
Shutter to Shot Time*(8.06)*
Shutter to shot speed has been improving on compact cameras overall. When we held the shutter release halfway down, until the FZ7 set the focus, pressing the shutter yielded a virtually immediate response. The fastest we can measure is a 0.01 of a second delay, so we’d have to say that this is the lag time. Shutter delay won't be a problem if the camera is pre-focused. The FZ7 is much slower, however, when time for autofocus is included. When the camera had to focus, our fastest time was 0.47 seconds.