Olympus E-420 Exposure

Saturation & Hue Accuracy
Accurate color and saturation, with only minor shifts in hue and intensity.

Saturation. The Olympus E-420 pushes strong reds, blues and some greens just a little, but actually undersaturates other greens, and cyan tones slightly. Thus, color saturation is a little truer to life than many 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. In this case, the E-420 did render skin tones a bit on the pale, pink side in most cases. Still, results are quite reasonable, well within an acceptable range. 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 E-420 showed only a few small color shifts relative to the correct mathematical translation of colors in its subjects, but had pretty good accuracy overall. Most noticeable was a shift in reds toward orange, and orange toward yellow, with some shifts in cyans and blues as well. Hue is "what color" the color is.

Saturation Adjustment
The Olympus E-420 lets you adjust the image saturation, contrast, and sharpness in five steps each. As can be seen below, the saturation adjustment worked moderately well, providing a reasonably fine-grained adjustment over a fairly useful range of control. The saturation adjustment also has almost no impact on contrast. That's how it should work, but we've often found interactions between saturation and contrast (and vice versa) on the cameras we test.

The table above shows results with the default as well as lowest and highest available saturation settings. See the Test Shots or Thumbnails index page for more (look for the files named E420OUTSAT0x.JPG). Click on any thumbnail above to see the full-sized image.

Exposure and White Balance

Indoors, incandescent lighting
Auto white balance is quite warm, but Incandescent, Manual and 2,700 Kelvin white balance settings produce good color. Slightly above average positive exposure compensation required.

Indoors, under normal incandescent lighting, the Olympus E-420 produced very warm color with its Auto white balance setting. The Incandescent setting wasn't too far off the mark, but had a slightly warm cast to it. Both the Manual and 2,700-degree Kelvin settings produced more accurate results. It was a bit of a toss-up between them, as the Manual setting was a hint warm and the Kelvin option a little more true to white value. Though the Manual setting did preserve a touch of the original mood, the 2,700-degree Kelvin mode produced the most accurate overall color. At +1.3 EV, slightly above average amount of positive exposure compensation was required for this shot. Color looks good throughout the frame, with only the slightest purplish tints in the blue flowers. (Many digital cameras reproduce these flowers with a dark, purplish tint, so the E-420 actually performs a little better than average 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
Good colors overall, though a tendency toward a warm cast and high contrast hurts both highlight and shadow detail. Above average exposure accuracy outdoors.

Outdoors, the Olympus E-420 tended to lose highlight detail under harsh lighting while requiring a lower than average amount of positive exposure compensation of +0.3 EV. Contrast was quite high, resulting in clipped highlights in Marti's shirt and some of the flowers, and lost shadow detail in the darker areas. (This reinforces our dynamic range measurements, which showed that the E-420 has less dynamic range than most SLRs currently on the market.) The outdoor house shot has good exposure and natural looking color.

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

Resolution
Very high resolution, 1,650 ~ 1,700 lines of strong detail.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,700 lines per picture height in the horizontal direction, and about 1,650 in the vertical direction. Extinction didn't occur until past the 2,000 line limit of this chart. 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
Pretty good detail, but images are a little soft overall. Some noise suppression visible in the deep shadows.

Sharpness. The Olympus E-420 captured a lot of detail, but its images straight from the camera are slightly soft overall. Even in the high contrast shot above, there's only slight edge enhancement visible along the edges of the house and thicker branches. These images take unsharp masking fairly well, however. 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 visible noise suppression in the shadows, though quite a bit of fine detail in the strands of hair remains visible. 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, Olympus E-420 JPEGs are pretty detailed, but a little soft. As expected, more detail can be obtained from carefully processing RAW files, though, without additional sharpening artifacts. 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. Examples include in-camera Super Fine JPEG, RAW file processed through Olympus' Studio software, and the same file with sharpness increased by 2. Note the increase in overall contrast. The fourth crop was processed in Adobe Camera Raw 4.4.1, using 300% unsharp masking with an 0.3 pixel radius.

ISO & Noise Performance
Low noise at ISO 100 and 200. Noise visible from ISO 400 up, but fine-grained. Good subtle detail retention, even at ISO 1,600.

The Olympus E-420 produced low noise at its lower sensitivity settings, however we start to see some fine-grained noise at ISO 400. As you'd expect, noise becomes more apparent at ISO 800, but noise is still quite fine-grained and not much detail has been lost to noise reduction. There is also very little sign of chroma noise, which some find more objectional. Even at ISO 1,600, the highest sensitivity supported by the E-420, though noise pixels are quite bright, noise remains fairly fine-grained, and there is still quite a bit of subtle detail to work with. Chroma noise is still low, but you can see some yellow and magenta blotches in the shadows. See the Print Quality section to find out what the recommended maximum size print is at each ISO setting.

Extremes: Sunlit and low light tests
High resolution with strong overall detail, though details are slightly soft. High contrast and limited shadow detail, however. Fairly good low-light performance, capable of capturing bright images under average city street lighting, and much darker conditions with manual intervention.

Sunlight. The Olympus E-420 had a hard time with the deliberately harsh lighting of the above test, producing rather high contrast with washed-out highlights and deep shadows. Though Marti's face still looks a little dark at +0.3 EV, I preferred that shot to the image at +0.7 EV, which had too many blown highlights for my preference. (In "real life" though, be sure to use fill flash in situations like the one shown above; it's better to shoot in the shade when possible.) 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.)

Contrast Adjustment
We really like it when a camera gives us the ability to adjust contrast and saturation to our liking. It's even better when those adjustments cover a useful range, in steps small enough to allow for precise tweaks. While the E-420 gives you five settings each for contrast, saturation and sharpness, we wished it had a little more range on the low side for the contrast adjustment.

At its lowest contrast setting, the E-420 did a fairly good job of preserving highlight detail (some were still blown, hence the desire for more range on the low end of the settings), maintaining natural-looking skin tones, and holding nice detail in the shadows. The E-420 captures good color outdoors, though just slightly on the warm side. Overall, very good results here, especially when the contrast setting is tweaked.

The series of shots above shows results with several different contrast adjustment settings, showing the default as well as both extremes. While you can see the extremes, it's hard to really evaluate contrast on small thumbnails like these, click on any thumbnail to go to the full-size image.

One very nice feature of Olympus's contrast adjustment is that it has very little effect on color saturation. Contrast and saturation are actually fairly closely coupled, it's a good trick to be able to vary one with out the other changing as well. Olympus did a good job here.

Olympus's Gradation Settings
Similar to dynamic range optimization systems from other manufacturers, the E-420's Auto Gradation setting applies local contrast adjustments in an attempt to preserve shadow detail and prevent highlight clipping. Below are examples of the various settings available applied to our outdoor portrait shot.

As you can see by comparing to the crops from the Normal setting, the Auto setting does a very good job of preserving most of the highlights in the flowers, while simultaneously lightening the shadows below the bouquet. Shadow noise is more apparent; however, this is quite normal when darker tones are lightened. The Low Key setting applies Gradation for dark subjects (in the crops above, you can see that it preserved the highlights but didn't lighten the shadows), while the High Key setting does the opposite for bright subjects (preserving shadow detail but not toning down the highlights). Note that the Contrast setting is ignored when Gradation is set to anything other than Normal.

Low light. The Olympus E-420 performed reasonably well on the low-light test, capturing usable, if not bright images at the lowest light level with the lowest sensitivity setting (ISO 100). Images are a little dim at the lower light levels though. This appears to be an issue with the E-420's metering, as one would expect the exposure duration to double for each decrease in light level in the table above, as the aperture is constant. You can always add exposure compensation or use manual mode to get around this limitation. Color balance is just a bit warm from the Auto white balance setting. Noise was fairly low up to ISO 400, but as expected, became more noticeable with higher ISOs. Some slight horizontal banding was evident at higher ISOs as well. There were also a few bright pixels visible when noise reduction was turned off at the lowest light level, but that's quite normal. The camera's autofocus system was able to focus on the subject almost down to the 1/8 foot-candle light level unassisted (and in complete darkness 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. (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.)

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.) Digital SLRs like the Olympus E-420 do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects.

Print Quality
Good print quality, great color, great 13x19-inch prints. ISO 1,600 images are surprisingly good at 8x10, even better at 5x7.

Output from the Olympus E-420 was good enough to produce sharp 13x19-inch prints. At 16x20, its prints were softer looking, but perfectly fine for wall or table display. ISO 200 images are a bit soft for 13x19, but better at 11x14 inches. ISO 400 images held together for very good 11x14-inch prints, and ISO 800 also withstood 11x14-inch print size; it's a little soft, but not at all bad. ISO 1,600 made good 8x10-inch prints, barely distinguishable from ISO 800 at the same size. They clean up more at 5x7, but would serve well at 8x10. Overall, pretty impressive printed performance from the Olympus E-420.

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.)