Panasonic GF1 Image Quality

Saturation & Hue Accuracy
Good color and hue accuracy over most of the spectrum, with minor oversaturation and shifts in some colors. Some issues with orange through yellows, though.

Saturation. The Panasonic GF1 pushes reds, dark greens very slightly, blues and purples a fair bit, while slightly undersaturating lighter greens, some cyans and oranges. Bright yellows are undersaturated somewhat more. While the default saturation of 106.9% (6.9% oversaturated) is a bit higher than that of the G1 (104.9%) it's just slightly lower than in the GH1 (110.9%), as well as most other consumer cameras. 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, the Panasonic GF1 did well, producing natural-looking skin tones, though just slightly on the pinkish side. 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 GF1 pushed cyan toward blue, red toward orange, and orange toward yellow. In the orange through yellow range, shifts were pronounced enough that colors there are poorly delineated from each other and all have a brownish/greenish hue. These shifts were especially apparent in the yellow through orange yarn of our Still Life test image. The camera's average color error wasn't that large, but its concentration in this one part of the spectrum makes it pretty noticeable. (The blue to cyan shift is very common among the digital cameras we test; we think it's a deliberate choice by camera engineers to produce better-looking sky colors.) As noted in Shawn's shooter's report text, and again on our Imatest page, though, the orange-yellow problems are significantly mitigated by working with RAW files and using a good-quality third-party RAW converter. Hue is "what color" the color is.

Saturation Adjustment
The Panasonic DMC-GF1 lets you adjust the image saturation, contrast, and sharpness in five steps each. As can be seen below, the saturation adjustment was very subtle. We usually argue in favor of more subtle adjustments for saturation on the cameras we test, but the Panasonic GF1 goes a bit too far in that direction; we'd like to see a wider range here (more steps), but still with the fine steps the GF1 currently offers.

The table above shows results with the default as well as the two "extreme" saturation settings. Click on any thumbnail above, then click again to see the full-sized image.

Exposure and White Balance

Indoors, incandescent lighting
Slight warm cast with Auto, very warm with Incandescent, very good color with the Manual and 2,600 Kelvin white balance settings. Slightly higher than average positive exposure compensation required.

Indoors, under normal incandescent lighting, color balance was just slightly warm with the Auto white balance setting, though the Panasonic GF1 did much better than most digital SLRs in this regard. (While slightly warm, results with the Auto setting were quite acceptable, and many users in fact prefer a slightly warm look in situations like this, to better represent the mood of the original lighting.) Results with the Incandescent setting were much warmer; the Incandescent setting looks like it might be adjusted to match professional studio lighting, a little odd for a decidedly consumer camera model. The Manual setting produced the most accurate results, though the 2,600 Kelvin setting wasn't far off the mark either, being just slightly warmer. The Panasonic GF1 required a slightly higher than average amount of positive exposure compensation here, at +0.7 EV. (Most cameras we've tested require about +0.3 EV for this shot.) Overall color looks good, though the blue flowers look a touch purplish, probably due to the DMC-GF1's tendency to punch up reds a little. (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
Bright colors overall, though a tendency toward high contrast under harsh lighting. Average exposure accuracy.

Outdoors, the Panasonic Lumix DMC-GF1 performed pretty well, with good color but (very) slight overexposure in the outdoor far-field house shot. The Panasonic DMC-GF1 required an average amount of positive exposure compensation (+0.7 EV) to keep facial tones reasonably bright on the "sunlit" portrait test, which led to blown highlights in her shirt. Default contrast is on the high side, but fortunately, there's a contrast adjustment to help compensate. Overall, good results here, especially when the contrast setting is turned down (see Extremes section below).

See full set of test images with explanations
See thumbnails of all test and gallery images

Resolution
Very high resolution, 1,700 ~ 1,800 lines of strong detail.

In camera JPEGs our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,750 - 1,800 lines per picture height horizontally, and about 1,700 lines in the vertical direction. Extinction didn't occur until about 2,700 lines horizontally and vertically. We weren't able to extract much more resolution by processing the GF1's RW2 files using Adobe Camera Raw 5.5, but ACR did hold definition in the target lines a bit better than the camera's own JPEG conversion did, making the target lines more distinct at high frequencies. (For what it's worth, the Panasonic GF1 seems to use higher default sharpening on its JPEG images than did either the G1 or GH1 before it. What we see above is technically over-sharpening (note the halos around the numerals and target lines), but the results on lower-contrast subjects just comes out looking much sharper than what we saw with the previous models.)

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.

See full set of test images with explanations
See thumbnails of all test and gallery images

Sharpness & Detail
Very good sharpness overall, though edge-enhancement artifacts on high-contrast subjects are visible. Moderate noise suppression visible in the shadows.

Sharpness. The Panasonic GF1 captures sharp, detailed images overall, though a few edge enhancement artifacts are visible on high-contrast subjects such as the branches in the crop above left. Comparing to the earlier G1 and GH1, the GF1's detail rendering seems to be a bit better, and it also applies more sharpening in its JPEGs at the default settings. On some high-contrast subjects (like our resolution test target), the GF1's sharpening leaves noticeable halo artifacts, but on natural subjects such as those shown above, the oversharpening isn't nearly as evident. 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 some moderate noise suppression artifacts in the darkest areas of the model's hair, smudging individual strands together, though quite a few strands are visible in the lighter shadows. Overall detail is better than average, but there are some odd color blotches (particularly visible on the left edge of the crop above), that we believe may be the result of insufficient anti-aliasing filtering, and the de-mosaicing problems that produces. (We also saw these with previous G series cameras, but only in the very fine, reddish detail of the mannequin's hair. This is something that we've seen with a number of other cameras in the past, including several SLRs.) 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.

RAW vs In-Camera JPEGs
As noted above, the Panasonic GF1 produces sharp in-camera JPEGs. As is almost always the case, though, quite a bit more detail can be obtained from carefully processing RAW files than can be seen in the in-camera JPEGs. The Panasonic GF1's JPEGs are quite good straight from the camera, but it's surprising how much more detail is visible after processing in a good RAW converter. Take a look below, to see what we mean:

In the table above, mousing over a link at the bottom will load the corresponding crop in the area above, and clicking on the link will load the full resolution image.

SilkyPix (the RAW converter Panasonic bundles with their RAW-capable cameras) is pretty sophisticated in the controls it provides for tweaking your photos. In the crops above, though, we ignored its multiple in-application sharpening controls and used only its output unsharp masking, which we set to 350%, a radius of 0.3 pixels, and a threshold of 0. File output is actually a logical place to apply it, as you'll want to use different sharpening settings for printing at different sizes, but we found it awkward not being able to preview the effect of the unsharp masking on-screen.

Adobe Camera Raw 5.5 was used for the ACR conversion version. The image was then sharpened in Photoshop using unsharp masking at 300% and radius of 0.3 pixel.

As you can see, both RAW conversions contain a lot more fine detail than the camera JPEG: The Panasonic DMC-GF1 rewards RAW shooters with really excellent detail. The bundled SilkyPix RAW converter can give Adobe Photoshop and Camera Raw a good run for the money, when it comes to the detail department, but details in the pine needles above reveal that it's de-mosaicing algorithms aren't quite up to those of Photoshop. (We hadn't previously noticed this significant a difference; wonder if recent changes to either SilkyPix or Adobe Camera Raw have had an impact in this area.)

ISO & Noise Performance
Low noise up to ISO 400, moderate to high at higher ISOs.

The Panasonic GF1's images are quite clean at ISOs 100 and 200. We start to see a very fine, tight "grain" pattern at ISO 400, but detail is still pretty good, with just a bit of chroma noise creeping into the shadows. The grain is slightly more evident at ISO 800, there's more chroma noise and detail starts to suffer due to blurring caused by noise reduction. At ISO 1,600, we see additional detail loss, as well as purple and yellow blotches. At ISO 3,200, noise grain is much coarser and blurring stronger, resulting in the loss of most fine detail. That said, like the Panasonic GH1, the GF1's high-ISO images are improved over those of the earlier G1, and are generally better-looking than we've come to expect from Four-Thirds format cameras in the past. The Panasonic GF1 seems to deliver more acuity than either previous camera at low ISOs, and none of the "banding" we saw in the GH1 at the highest ISO settings. Perhaps because it shares the G1's sensor, though, it does show more noise in deep shadows than the GH1 did. Bottom line, we'd give the nod to the Panasonic GF1 over both earlier models when it comes to overall image quality, but do miss the cleaner shadows the GH1 provided at high ISOs. As always, see the Print Quality section below for maximum recommended print sizes at each ISO.

Extremes: Sunlit and low light tests
High resolution with good overall detail, but somewhat high default contrast and limited dynamic range. Very good low-light performance.

Sunlight. The Panasonic Lumix DMC-GF1 struggled a bit with the deliberately harsh lighting of this test, as contrast was a little high at its default setting, and the dynamic range somewhat limited. Although skin tones in the face are a bit dark at +0.7 EV with the default contrast, we preferred it to +1.0 EV exposure overall, because there were fewer clipped highlights. Depending on the photographer, you could lean one way or the other. Pros and advanced users will want to shoot darker, to hold highlight detail. For those DMC-GF1 owners that are going to want to just print an image with little or no tweaking, the +1.0 image would probably produce a better-looking uncorrected. The bottom line though, is that the GF1 had difficulty with the wide dynamic range of this shot, at least with its default settings.

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.)

Contrast Adjustment
As mentioned previously, the camera's limited contrast adjustment was at least some help in handling the harsh lighting.

At its lowest contrast setting, the Panasonic GF1 did a better job of preserving highlight detail, maintaining fairly natural-looking skin tones, and holding more in the shadows, but its limited dynamic range still makes it perform a bit below average in this regard.

The shots above show the results of the minimum, default and maximum contrast settings. While you can see the extremes, it's pretty hard to evaluate small differences in contrast on small thumbnails like these, click on any thumbnail to go to the full-size image. That said, unlike the Saturation adjustment, the control for Contrast is not quite as subtle in its effect. It seems to basically leave the strongest highlights alone, and then apply a proportional boost to tones as it moves down the tone curve. To make the most of it in a shot like this, you'd want to drop the exposure to hold the highlights and then apply a good amount of contrast reduction (probably the maximum, the steps are pretty small).

The Panasonic GF1's contrast adjustment helps a little with the strong highlights here, but we'd really like to see more steps of this size, covering a slightly greater range. And even with the lowest contrast setting, the dynamic range isn't terribly impressive: While dropping the exposure slightly helped the highlights, and the contrast adjustment opened up the shadows somewhat, the camera still struggles with the deliberately harsh lighting of this test. (Which means it will also have issues with strong, direct sunlight.) Lowering the contrast helps the visual appearance of images such as these, but doesn't result in any significant extension of the tonal scale, in either bright highlights or deep shadows

Panasonic's iExposure
The above shots are examples of Panasonic's Intelligent Exposure (or iExposure) at work. There are three levels of iExposure available: Low, Standard and High, plus Off. All three settings were an improvement over the Off setting, doing a pretty good job of pulling detail up out of the shadows and delivering a better exposure overall. With the exposure compensation off here, the net result is much better highlight preservation as well. While there's good tonality in the mannequin's face, and good detail in both highlights and shadows, the images looked a bit flat and dull overall. We suspect that shooting with iExposure enabled, but at an exposure compensation of +0.3 EV might brighten things up a bit overall, without blowing the highlights. - But we had to draw the line somewhere on testing, in the interests of getting this review out and then getting on to other cameras in our never-ending backlog. Bottom line, though, iExposure seems to provide a useful extension to the practical dynamic range of the GF1. (It's not likely increasing the technically defined dynamic range of the sensor any, because you'll see increased noise in the deep shadows proportional to whatever detail you're saving on the highlight end. As you can see above, though, it can make for much more usable/printable images when working under tough lighting conditions.)

Face Detection
Like most Point & Shoot cameras these days (and most DSLRs in Live View mode), the Panasonic GF1 has the ability to detect faces, and adjust exposure and focus accordingly. The GF1 does it automatically in Intelligent Auto (iAuto) mode, when a Portrait scene mode is selected, or when Face Detection AF mode is selected. As you can see from the examples above, it really works, as the image with face detection enabled is better exposed for the face. We'd prefer a slightly higher exposure as the mannequin's face is still a little dark, but if combined with Panasonic's Intelligent Exposure (see the example above), we believe it would deliver very nice exposures, even under very difficult lighting such as this.

Low Light. The Panasonic DMC-GF1 performed well in our low light test, capturing bright images down to the lowest light level we test at, at all ISO settings. This darkest level equates to about 1/16 the brightness of average city street lighting at night, so the DMC-GF1 should be able to take well-exposed photos in almost any environment in which you can see well enough to walk around in. Automatic color balance was pretty good (just slightly cool), something that's not a given at such low light levels. Using the default noise reduction setting, noise is low to moderate below ISO 800. At ISOs 800, 1,600 and especially 3,200, noise is a bit high compared to most DSLRs these days, but with hardly any of horizontal banding we saw from the Panasonic GH1 at the same light levels.

The camera's autofocus system was able to focus on the subject down to below the 1/16 foot-candle light level unassisted, which is excellent for a camera using contrast-detect autofocus, but the fast f/1.7 20mm kit lens probably has a lot to do with that. The DMC-GF1 does have a focus-assist light option which allows it to autofocus in total darkness, as long as the subject is within range and has sufficient contrast.

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.) Thanks to their phase-detect AF systems, digital SLRs tend to do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects. The GF1 uses contrast-detect autofocus, as is found in most point & shoot cameras, so its low-light focusing ability is less than that of some SLRs with phase-detect systems. That said, though, the larger, more sensitive pixels of the GF1's sensor do better under dim lighting than do the tiny pixels of most point & shoots, (A useful trick 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.)

Print Quality

Excellent print quality, good color, sharp 13x19 inch prints from camera JPEGs, 16x20 inch ones from RAW files. (Even 20x30 prints from RAW are very usable for wall display.)

Like the G1 and GH1 before it, the Panasonic GF1's printed output is really impressive. Even JPEGs are great, except for the odd color shift we saw in yellows and oranges. Detail, though, is nothing short of amazing. JPEGs were able to produce good quality 16x20-inch images at ISO 100 and 200 with no trouble at all.

ISO 400 and 800 shots looked just fine at 13x19 inches, which is amazing. Naturally, ISO 800 shots showed some chroma noise in the shadows at this size, but it wasn't objectionable, and the detail is quite amazing.

ISO 1,600 shots looked great at 8.5x11 inches, and ISO 3,200 shots were usable at 8x10 and better at 5x7.

Colors do fade a bit as ISO rises, but not too badly, and blacks tend to fade as noise rises in those shades. Some colors oversaturate, like reds, at higher ISOs, but that too is expected. Overall, the Panasonic GF1 is an amazing performer, delivering good detail at a surprising range of print sizes. ISO 800 shots at 13x19 inches is an amazing feat.

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 Pro9000 Mark II studio printer, and on the Canon Pixma MP610 here in the office. (See the Canon Pixma Pro9000 Mark II review for details on that model.)