Olympus E-620

Noise Reduction (5.36)

Turning off noise reduction entirely to maximize image sharpness produced easily visible image noise by the time we reached ISO 400, and the problem accelerates rapidly from that point. The low noise reduction setting offers a major improvement at high ISO levels, but not enough to solve the problem. And while the two highest settings maintain sub-2% image noise across the board, the loss of image sharpness is readily apparent.

The E-620 noise curves are all tightly clustered for red, green, blue, yellow and luma (gray) noise, with no single component color spiking (which can be highly visible). More on how we test noise.

It isn’t easy to cram 12 million pixels into a Four Thirds-size sensor — the individual light receptors have to be tiny and closely packed, leading to elevated noise levels, as shown in our lab testing. The Olympus E-620 tested at approximately the same noise level as the Olympus E-30, which is to say, poorly. particularly at high ISOs. Even a noise reduction system that does sharply reduce noise levels, as shown in the chart below, couldn’t tame the problem, and as expected leads to noticeable loss of image detail. Overall the two trail the other cameras in our comparison group by a wide margin in this area.

We test image noise performance by shooting the X-Rite ColorChecker chart at each available ISO level under bright studio illumination (low-light performance is tested separately). When multiple noise reduction settings are available, we shoot at each of them, and the score is based on a camera’s overall performance. Ordinarily we turn dynamic range enhancement features off for this test, since this digital manipulation can increase image noise, but Olympus doesn’t offer ‘off’ as an option. Instead, we shot at the normal setting for ‘gradation,’ the Olympus term for dynamic range enhancement.

ISO Options

Available ISO values range from 100 to 3200. The ISO step value can be changed from the default 1 EV to 1/3 EV if you prefer finer increments.

In Auto ISO mode, both the default value to be used and the maximum allowable ISO can be set, from 200 to 3200 in 1/3 EV increments. ISO bracketing, a relatively unusual feature, is also available, providing a three-shot sequence with 0.3, 0.7 or 1 EV increments.

Focus Performance

The Olympus E-620 uses a seven-point autofocus system, with . There are two available modes. All-target autofocus lets the camera choose among the seven available points, while single target AF uses one focus point selected by the shooter. The focus point can be chosen by pressing the AF target button behind and to the right of the shutter, then adjusting using the control dial (pretty easy) or the four-way controller (pretty tricky if you have the viewfinder up to your face).

For an extra level of fine control, there are two settings for single-point autofocus. The default Normal setting uses an area slightly larger than the target indicated, while Small focuses only on that single tiny point.

Five focus modes are available when shooting with the viewfinder: Single, Continuous, Manual, Simultaneous Single Autofocus and Manual Autofocus (where the camera autofocuses, then you adjust manually), and Simultaneous Single Autofocus and Manual Autofocus (where you first set the focus manually, then the camera attempts to maintain that focus as the subject moves). Live View autofocus is described in the separate Live View section above.

There is no dedicated autofocus assist lamp on the Olympus E-620. Instead, the pop-up flash emits a series of quick bright pulses, effective over a greater distance than an autofocus assist light, but a bit less subtle if taking indoor candids or baby pictures were what you had in mind.

We found autofocus speed rather slow with the kit lens, especially in spot focus mode. Relatively dim indoor room lighting resulted in a notable lag in focus and, while popping up the flash did solve the problem, other SLRs do a better job dealing with similar lighting conditions. Once focus is achieved, though, the continuous autofocus system did a good job tracking all but the fastest-moving subjects.

Long Exposure (7.91)

Our long exposure test is a two-stage process, measuring both color error and image noise over a range of shutter speeds (1, 5, 10, 15 and 30 seconds). The Olympus E-620 outperformed the more expensive Olympus E-30 substantially in the color error testing, but both had mediocre results for long exposure image noise (as we’ll see in the Noise testing section below, image noise remains the Achilles heel of Olympus SLRs overall). As a result, the combined long exposure score for the E-620 is superior to the E-30, but far surpassed by the Canon Rebel XS and Nikon D90.

Our long exposure testing procedure calls for illuminating the X-Rite ColorChecker chart evenly at a low illumination level and shooting it at five shutter speeds, with and without long exposure noise reduction. Ordinarily we turn off any dynamic range optimization system for this test, since it can affect results. The Olympus doesn’t allow an ‘off’ setting, though. After some experimentation we went with the Normal setting for all of our test procedures. More on how we test long exposure.

As seen here, the Olympus E-620 maintained a strong, steady color accuracy performance across the range of shooting times, with only minor variation between photos shot with noise reduction on and off.

Image noise, shooting here at ISO 400, was also consistent, but on the high side (a shorter bar indicates lower noise levels). We did find it necessary to lower the illumination level somewhat to keep the 30-second exposure from blowing out and skewing the test results.

Based on previous testing experience, it doesn’t surprise us to note that, despite promises to the contrary, turning on long exposure noise reduction actually produced slightly inferior results. The concept of long-exposure noise reduction is that the camera takes a second shot, with the shutter closed, after the actual photo is taken, then digitally corrects the image based on the noise present in that second exposure. The problem is, image noise is inherently random, leading to corrections where none is required and missed opportunities for fixes in other areas.

Neither Olympus model excelled in our long exposure testing, though the E-620 does show improvement over the previous model.