Panasonic DMC-LZ7 Exposure

Saturation & Hue Accuracy
Very good overall color and hue accuracy, with minor oversaturation of some colors.

Saturation. The Panasonic DMC-LZ7 oversaturates strong red and blue tones slightly, but undersaturates bright yellows. This is quite typical of consumer models, but we found its colors pleasing on a wide range of typical subjects. Most consumer digital cameras produce color that's more highly saturated (more intense) than found in the original subjects. This is simply because most people like their color a bit brighter than life.

Skin tones. Here, with the color balanced properly for the light source, the LZ7's skin tones were a little flat and clay-like, with only slight warmth. However, in some lighting, skin tones appeared a little pink. Where oversaturation is most problematic is on Caucasian skin tones, as it's very easy for these "memory colors" to be seen as too bright, too pink, too yellow, etc.

Hue. The Panasonic LZ7 showed small color shifts relative to the correct mathematical translation of colors in its subjects. Cyan is pushed slightly toward blue, red toward orange, and yellow toward green, but overall color is actually pretty accurate. Hue is "what color" the color is.

Exposure and White Balance

Indoors, incandescent lighting
Good overall color with Manual white balance, though pinkish skin tones. Slightly higher positive exposure compensation than average.

Color balance indoors under incandescent lighting was actually pretty good in Auto white balance mode, though overall color was a little pinkish. In the opposite direction, the Incandescent setting produced a very warm cast. Manual mode was the most accurate overall, though skin tones are just a little pink. The LZ7 required a +1.3 EV exposure compensation boost to get a good exposure, a little higher than average for this shot. Overall color with the Manual white balance setting is good, though the blue flowers are dark and purplish. (Many digital cameras reproduce these flowers with a dark, purplish tint, so the DMC-LZ7 struggled a bit here.) Our test lighting for this shot is a mixture of 60 and 100 watt household incandescent bulbs, a pretty yellow light source, but a very common one in typical home settings here in the U.S.

Outdoors, daylight
Slightly flat color, good exposure, though with high contrast in harsh lighting.

Outdoors, the Panasonic Lumix DMC-LZ7 did reasonably well, with pretty good exposure in the outdoor house shot, except that shadows are too deep and highlights too bright. Though the shirt is almost completely blown out in the +0.3 EV portrait shot, this is the closest it gets to good skin tones without excessive highlights taking over the face. Shadow detail is limited, both from noise and some noise suppression. Overall color looks pretty good, though greens are a hint dark in the house shot, and skin tones are flat and clay-like.

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Resolution
High resolution, 1,400 to 1,500 lines of strong detail.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,400 lines per picture height horizontally and 1,500 lines vertically. Extinction occurred around 2,000 lines. Use these numbers to compare with other cameras of similar resolution, or use them to see just what higher resolution can mean in terms of potential detail.

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Sharpness & Detail
Reasonably sharp images, though noise and noise suppression contribute to loss of definition. Some edge-enhancement is also visible in high contrast subjects.

Sharpness. Noise pattern and some noise suppression decreases definition even in bright subjects like the house shot above. Edge enhancement artifacts are also visible along the high contrast areas. Edge enhancement creates the illusion of sharpness by enhancing colors and tones right at the edge of a rapid transition in color or tone.

Detail. The crop above right shows fairly high noise suppression, with darker areas of Marti's hair showing limited detail, where the individual strands eventually become lost in the blurred shadow areas. Noise-suppression systems in digital cameras tend to flatten-out detail in areas of subtle contrast. The effects can often be seen in shots of human hair, where the individual strands are lost and an almost "watercolor" look appears.

ISO & Noise Performance
Low to moderate noise at the normal sensitivity settings, though a jump in noise with strong blurring at the higher settings.

Noise levels and efforts to suppress noise are quite evident at the Panasonic DMC-LZ7's lower sensitivity settings, with much higher noise at ISO 400 and up. Even at ISO 200, noise reduction artifacts are fairly strong, with blurry fine detail and some blotchiness, with soft yellow and purple patches (though these are less pronounced than we normally see). At ISO 1,250, noise is so strong that the color balance shifts to violet and practically all fine detail is lost.

Extremes: Sunlit and low light tests
High resolution with strong overall detail, but slightly high contrast and limited shadow detail. Good low-light performance, capable of capturing bright images under average city street lighting at night, and darker conditions using Scene modes.

Sunlight:
The Panasonic Lumix DMC-LZ7 had some difficulty dealing with the deliberately harsh lighting in the test above, producing very high contrast with washed-out highlights and deep shadows. Shadow detail is quite limited, with an interesting noise grain pattern that loses all fine detail here. Noise is also visible in the lighter parts of the image, also obscuring fine detail. The camera required a little less than average compensation to get proper exposure of skin tones, at +0.3 EV, but unfortunately blows the detail in the shirt, a clear indication of excessive contrast preventing capture of a good sunlit image. In the real world, be sure to use fill flash in situations like the one shown above; it's better to shoot in the shade when possible.

Because digital cameras are more like slide film than negative film (in that they tend to have a more limited tonal range), we test them in the harshest situations to see how they handle scenes with bright highlights and dark shadows, as well as what kind of sensitivity they have in low light. The shot above is designed to mimic the very harsh, contrasty effect of direct noonday sunlight, a very tough challenge for most digital cameras. (You can read details of this test here.)

Low light:
The Panasonic Lumix DMC-LZ7 performed about average on the low-light test in Auto mode, capturing bright images almost down to the lowest light level, but only at the highest (and noisiest) sensitivity setting (ISO 1,250). At the lowest sensitivity setting, images are still a bit dim even at one foot-candle, which is about the same as average city street lighting at night. Noise is high, especially at the higher sensitivity settings, but this is expected. There are however several scene modes that improve on this performance. Night Scene mode was able to capture clean, reasonably bright images down to about 1/4 foot-candle at ISO 100, and the Starry Sky scene mode (which offers 15, 30 and 60 second exposures at ISO 100), was able to capture bright, clean images all the way down to 1/16 foot-candle, the lowest level we test at. High Sensitivity mode was also able to capture bright images down to 1/16 fc, but detail was quite limited and noise was high. Color balance was pretty good with the Auto white balance setting. The camera's autofocus system worked well also, as it was able to focus on the subject down to the 1/16 foot-candle light level unassisted, and to much darker with the AF assist enabled. Keep in mind that the longer shutter speeds here demand the use of a tripod to prevent any blurring from camera movement. In general, anything slower than 1/30 second is hard to hand-hold without blurring, though the LZ7's optical image stabilization will allow 2-4x slower shutter speeds while still getting sharp results hand-held. (A useful trick for really slow shutter speeds is to just prop the camera on a convenient surface, and use its self-timer to release the shutter. This avoids any jiggling from your finger pressing the shutter button, and can work quite well when you don't have a tripod handy.)

How bright is this? The one foot-candle light level that this test begins at roughly corresponds to the brightness of typical city street-lighting at night. Cameras performing well at that level should be able to snap good-looking photos of street-lit scenes.

NOTE: This low light test is conducted with a stationary subject, and the camera mounted on a sturdy tripod. Most digital cameras will fail miserably when faced with a moving subject in dim lighting. (For example, a child's ballet recital or a holiday pageant in a gymnasium.) For such applications, you may have better luck with a digital SLR camera, but even there, you'll likely need to set the focus manually. For information and reviews on digital SLRs, refer to our SLR review index page.

Coverage and Range
Modest flash power at close range, and not a match for the camera's 6x optical zoom. Our standard shots required more than average exposure compensation, coverage was pretty uniform.

Coverage. The Panasonic Lumix DMC-LZ7's flash couldn't quite keep up with its zoom range, as the telephoto shot above was very dark. Coverage was a bit uneven at wide angle, but not too bad. On the Indoor Portrait, the camera required more than the average amount of positive exposure compensation at +1.3 EV. Even here, the exposure is just slightly dim, but anything brighter resulted in highlights that are too strong. Results were better in Night Portrait mode, though the camera required even more positive compensation at +1.7 EV. The longer exposure resulted in an orange cast from the background incandescent lighting, but results here were more pleasing to my eye than the cooler color of the standard flash shot.

ISO 100 Range. At wide angle, flash shots at ISO 100 remained fairly bright out to a distance of about 8 or 9 feet, decreasing in brightness from that point on. At full telephoto and ISO 100, the target at 6 feet was already dim.

Manufacturer Specified Flash Test. In the wide angle shot above, the DMC-LZ7 seems to perform exactly as Panasonic says it will, producing a good exposure at the rated distance with its ISO set to Auto (which selected ISO 100). At telephoto, the image is also fairly bright, without an ISO boost. Our standard test method for flash range uses a fixed setting of ISO 100, to provide a fair basis of comparison between cameras. We've now also begun shooting two shots using the manufacturer-specified camera settings, at the range the company claims for the camera, to assess the validity of the specific claims.

Print Quality
Good print quality, good color, sharp 11x14 inch prints. ISO 400 images are soft at 8x10, ISO 400 and 800 shots are better at 5x7, and ISO 1,250 shots are usable at 4x6. ISO 3,200 images are soft and smudgy at 4x6.

The Panasonic Lumix DMC-LZ7 had enough resolution to make good looking 11x14 inch prints, though there was some luminance noise in the shadows. ISO 200 shots are soft at 11x14, too much anti-noise processing that blurs detail. This effect was lessened at 8x10 inches. ISO 400 shots are soft at 8x10, and colors are starting to run together like a watercolor painting. At 5x7, however, both ISO 400 and 800 images look pretty good. ISO 1,250 images are smudgy but acceptable at 5x7, but surprisingly good at 4x6. Some noise is evident in the larger of the two, but it's handled well enough that most people won't notice. ISO 3,200 is probably fine for Web display at small sizes, but don't use it for important work that you'd want to print, because images are very soft even at 4x6. ISO 3,200 images are soft and cartoon-like at 4x6, so avoid this Scene mode for everything but very small Web-based photos.

Testing hundreds of digital cameras, we've found that you can only tell just so much about a camera's image quality by viewing its images on-screen. Ultimately, there's no substitute for printing a lot of images and examining them closely. For this reason, we now routinely print sample images from the cameras we test on our Canon i9900 studio printer, and on the Canon iP5200 here in the office. (See the Canon i9900 review for details on that model.)