Olympus E-620

	Resolution Summary
• Decent resolution results overall • Chromatic aberration well controlled, particularly for inexpensive kit lens • Distortion problematic only at extreme wide angle • Sharpness holds up well, particularly at prime shooting settings • Limited dynamic range will impact detail in high-contrast shots
	Noise	Page 5 of 17	White Balance

Resolution (10.31)

While the Olympus E-620 didn't match the stellar resolution performance of the E-30, we are still very happy with the test results here, particularly when we factor in the fact that we are shooting the E-620 with the inexpensive 14-42mm f3.5-5.6 kit lens, while the more expensive Olympus E-30 is not sold in a kit and was paired with a $500 14-54mm f/2.8-3.5 lens for our review.

We test for three factors, distortion, chromatic aberration and sharpness, and score based on the last two. The E-620 demonstrated exceptionally low distortion in all but the widest focal length, respectable chromatic aberration results and performed very well in our sharpness testing.

We test resolution by shooting a custom chart at three focal lengths (the widest angle, the longest telephoto and the midpoint of the zoom range), under bright studio illumination, at three apertures for each focal length. The resulting images are analyzed using Imatest software to determine sharpness (a test that is independent of megapixel count), lens distortion and chromatic aberration. Click here for more on how we test resolution.

Distortion
Shooting at 42mm we found barely a trace of barrel distortion, and at 29mm it only reached 0.24%. This figure climbed to 2.46% at the 14mm focal length, which is to be expected given the extreme angles involved.

Chromatic Aberration
The only significant trouble spot where chromatic aberration is concerned shows up at the widest 14mm focal length, which is not surprising. Otherwise, we found very little visible fringing in the test images.

Sharpness
The highest sharpness results were found at the 29mm focal length when shooting at f/5.0, where the lens could resolve 1712 lw/ph horizontally and 1700 lw/ph vertically at the center.

	Image Sharpness and Chromatic Aberration
	f/3.5			f/13			f/22
14mm

At the 14mm setting we encountered significant horizontal chromatic aberration from the midpoint out to the edges. Sharpness was very good from corner to corner, especially when shooting at f/3.5 and f/13.0, and even at f/22 remained acceptable.

	Image Sharpness and Chromatic Aberration
	f/5			f/13			f/22
29mm

Sharpness at 29mm remains high, with only the fully stopped down f/22 shots showing any significant softness. Chromatic aberration becomes less of an issue, as expected, though there are still some notable horizontal flaws at those troublesome midway points.

	Image Sharpness and Chromatic Aberration
	f/5.6			f/11			f/22
42mm

Shooting with the lens at full zoom we found chromatic aberration controlled well for an inexpensive lens, and sharpness very good across the board, particularly with the lens wide open.

As shown below, the Olympus E-620 held its own in our resolution testing, posting slightly higher scores than the kit-lens-equipped Canon Rebel XS and Pentax K2000 and maintaining parity with the Nikon D90, which was shot with a more expensive lens attached.

Resolution Score Comparison

Picture Quality & Size Options (12.60)

The E-620 offers seven image size options, but they're not all available at once, which seems unnecessarily complicated. Three settings are offered at any given time: Large, Middle and Small. There is only one option for Large, but Middle has three possible settings, and so does Small. The size that currently corresponds to Middle and Small settings is determined via section G of the custom settings menu. It feels like it would be far simpler and more flexible just to present a dozen settings on a single menu, and let the user scroll quickly to the desired choice using the control dial.

There are four compression options for JPEGs: Super Fine (1/2.7 compression), Fine (1/4), Normal (1/8) and Basic (1/12).

RAW shooting is available in the Olympus .ORF file format, either as a standalone file or with an attached JPEG image. The JPEG is saved in Large format with Fine compression.

Dynamic Range (3.44)

The curse of high-noise images rears its head here again, affecting the ability of our analysis software to detect clearly delineated steps of dynamic range in the standard Kodak chart we shoot. The Olympus E-620 did not fare quite as poorly as the Olympus E-30 on this test, but it still ranks well below the competition.

The advantage of a wide dynamic range is the ability to maintain detail in both very bright and very dark areas, which comes in handy when shooting contrasty scenes (a light-colored building with dark shadows cast by slanted sunlight, for example) and, of course, zebras. We test dynamic range by lighting the 20-patch Kodak Gray Scale chart at an even 3000 lux, shooting it at each available ISO and a range of aperture settings. These individual images are evaluated using Imatest software, which then analyzes the results at multiple apertures to calculate an overall dynamic range performance evaluation at each ISO. Click here for more on how we test dynamic range.

Even at basic ISO 100 and ISO 200 settings, the dynamic range demonstrated by the Olympus E-620 is poor, with a top result of only four and a half stops, compared to over seven stops at ISO 100 for the $599 Pentax K2000. No matter what ISO you shoot at, you're going to lack flexibility and fine detail in high-contrast scenes when shooting with the Olympus.

Dynamic Range

This chart shows the relative dynamic range results among our comparison cameras when shooting at ISO 200. This is the second Olympus camera we've shot recently that produced poor results on this test, indicating an unfortunate consistency undoubtedly linked to the high-megapixel, small-sensor challenge.

Dynamic Range Comparison

Short bars reflect lower performance results in the following scoring chart.

Dynamic Range Score Comparison

Image Stabilization (5.81)

The Olympus supports three different modes of in-camera image stabilization. I.S. 1 is the basic setting for shooting with stabilization turned on. I.S. 2 is used for shooting when panning horizontally: horizontal stabilization is turned off, vertical stabilization is active. I.S. 3 is for panning vertically, with horizontal stabilization active and vertical turned off. As you would imagine, we tested using the I.S. 1 mode. And the results prove the system is useful, but doesn't offer the dramatic sharpness gain we found when shooting with the Olympus E-30.

To test the effectiveness of a camera's image stabilization system, we mount it in a custom-designed computer-controlled rig that recreates a consistent series of horizontal and vertical movements, designed to mimic the pattern of a person's shaking hands at low and high levels. We shoot a brightly lit chart repeatedly and measure the image resolution of each shot using Imatest. These results are then statistically sampled to reveal the underlying pattern. Click here for more on how we test image stabilization.

With a fairly low level of shake, roughly what you'd expect from a person standing still and trying to hold the camera steady with two hands, we found the image stabilization system produced a modest loss of sharpness at the highest shutter speeds, but from 1/125 second on consistently offered a modest improvement.

Olympus E-620 Image Stabilization: Low Shake
Horizontal: Sharpness Vs Shutter Speed	Vertical: Sharpness Vs Shutter Speed

Revving up the level of shake to about what you'd find when trying to shoot one-handed, or while moving, the pattern remains similar. The 1/500 second shutter speed results measuring horizontal movement indicate a larger improvement than we'd expect, which held true even when we reshot the test. On the vertical side, there are minor differences one way or the other between having the IS system on or off until you hit 1/60 second, from which point the system consistently delivers a slight improvement.

Olympus E-620 Image Stabilization: High Shake
Horizontal: Sharpness Vs Shutter Speed	Vertical: Sharpness Vs Shutter Speed

The two Olympus camera produced very different results, which is probably at least in part due to the different physical dimensions, balance, lens types and focal lengths involved. For the E-620, the system proved marginally useful, but shouldn't be considered a major selling point when considering your options.

The chart below summarizes the image stabilization scores for three of our comparison cameras (test results are not available for the other two).

Image Stabilization Score Comparison

The chart below will help visualize the actual differences reflected in the data above. These are representative same-size crops taken from photos in our test group, at each horizontal shake level and shutter speed.

	Image Stabilization Comparison Table
	Low Shake IS Off	Low Shake IS On	High Shake IS Off	High Shake IS On
1/500
1/250
1/125
1/60
1/30
1/15
1/8