Olympus E1 SLRThe first "Four Thirds" system (almost) sees the light of day!<<Optics :(Previous) | (Next): Shutter Lag & Cycle Time Tests>> Page 6:Exposure & FlashReview First Posted: 06/24/2003, Updated: 03/16/2004 |
Exposure
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For long exposures, the E-1 offers both Noise Reduction and "Noise Filter" settings. Noise Reduction decreases the amount of image noise in long exposures by using a dark frame subtraction method to minimize fixed pattern noise. When enabled through the settings menu, Noise Reduction automatically engages on exposures longer than two seconds, or when an image has significant dark areas in it. The Noise Filter option addresses random pattern noise, which typically occurs in images captured at high ISO settings or in large areas of solid color, such as blue skies, regardless of exposure duration.
The E-1's Noise Filter option appears to use a pretty sophisticated algorithm that attempts to take image content into consideration when setting local noise-suppression thresholds. - The trick is to suppress random pattern sensor noise, without also suppressing more or less random fine detail in the subject. Olympus hasn't offered a detailed explanation of their Noise Filter algorithms, but the sketchy information given thus far sounds like they work in much the same way as some advanced Photoshop "actions" available on the market. The general idea is to first pass an edge-enhancement filter over the image to generate a mask through which the noise suppression filter is subsequently applied. Regions with high edge detail are deemed to contain useful image information, so the noise suppression filter is throttled back in those areas. (Conveniently, sensor noise will also be much less visible in areas where there's a lot of subject detail present.) By contrast, in flat areas of the image with little subject detail, the noise suppression algorithms are given free reign. Like the Shading Compensation feature, the Noise Filter option involves some pretty intense image processing, so it slows the writing of images to the memory card. - A SHQ-quality JPEG that takes 2.5 seconds to write normally requires roughly 14 seconds when Noise Filter processing is enabled. (Note too, that this special "Noise Filter" processing is additional image processing over and above the normal noise suppression algorithms that are applied to all images by essentially every digicam on the market.)
The E-1 has three metering modes available: ESP, Center-Weighted, and Spot. Exposure compensation is adjustable over an unusually wide range of -5 to +5 exposure equivalents (EV) in one-third-step increments, though you can also opt for one-half or full-step increments through the setup menu. If you're not sure about the exposure, an Auto Exposure Bracketing function can automatically capture a series of either three or five images at different exposure settings. (You can set the auto bracketing exposure increment to one, one-half, or one-third step sizes.) The AE Lock button on the back panel locks exposure and focus when pressed, the lock remaining in effect until the button is pressed a second time, the Shutter button is halfway pressed, or the shutter fired. Through the settings menu, you can set the button to lock only the exposure, only the focus, or both together. Light sensitivity is adjustable from 100 to 800 ISO equivalents, with an Auto setting available. If the ISO Boost option is enabled, however, the range expands to include settings for 1,600 and 3,200 ISO equivalents.
The E-1's white balance system appears to be quite a bit more sophisticated than those on most digicams out there, including many professional SLRs. For starters, it uses a hybrid system for determining the color balance of ambient lighting, with an independent white balance sensor on the camera's front, that works in conjunction with white balance information gleaned from the CCD. (The vast majority of digicams base white balance solely on image data collected from the CCD.) In my shooting, the E-1's white balance system generally seemed quite sure-footed. although the auto white balance option did leave more color cast in the incandescent-lit Indoor Portrait shot than I'd have liked. It's like that the external white balance sensor will have the greatest impact with unusual subjects dominated by a single color. Subjects like this can trick normal white balance systems into thinking that there's a color balance problem with the lighting when in fact it's the subject itself that has an overall color bias. This is the case with my "Musicians" test poster, which has an abundance of blue in it that often tricks digicam white balance systems into over-compensating, producing overly-warm images. The E-1 did indeed seem to be largely immune to this effect.
White balance options on the E-1 are quite extensive, with a full range of Kelvin temperature settings available, in addition to the custom settings. Twelve temperature settings are available in all, from 3,000 to 7,500 degrees K. (I'm pleased to see a wide range of Kelvin-calibrated white balance settings, but would *really* like to see it extend to lower values. - Common household incandescent lighting extends down to color temperatures of 2,400K and below, but Kelvin-based white balance options rarely extend that low.) Each of the Kelvin white balance settings can be adjusted across a range of +/- 140 degrees K, via the White Balance Compensation menu option that lets you shift the color a couple of MiReDs at a time. (MiReD stands for Micro Reciprocal Degree, each MiReD unit corresponding to roughly 10K of color shift, depending on the base color temperature you're correcting. The white balance adjustment in the E-1 shifts the color balance roughly 20K for each step, and has seven steps of adjustment above and below the primary setting.)
In addition to its wide range of Kelvin settings, the E-1 also sports an Auto option, and no fewer than four separate manual white balance settings. Each manual white balance setting can save a white balance value independently from the others, allowing you to store and quickly access four entirely different custom white balance values.
A White Balance Bracketing mode captures three frames in a series, with color adjustments in arbitrary units of +/- 1, 2, or 3. A Color Space option offers your choice of sRGB and Adobe RGB color spaces, and the camera also offers a very flexible Saturation adjustment. Under the Saturation adjustment, you can increase or decrease the overall saturation for all three RGB channels, or selectively boost saturation for specific colors. The overall control offers a total of five settings, corresponding to the default value plus two steps with higher or lower saturation. The color-specific saturation boosts don't offer any adjustment for the amount of the boost (it'd sure be nice if they did). Saturation can be boosted for reds, greens, blues, or for a softer red, corresponding to flesh tones.
The E-1 is also unusual (although not entirely unique) in the ability it gives the user to "edit" the RAW image data in-camera. Through a menu option, you can create new JPEG files from the RAW originals, changing color space, contrast, saturation, sharpness, white balance, and final image size.
A Self-Timer setting offers either a 12-second or two-second delay between the time the Shutter button is pressed and the time that the camera actually takes the picture. The E-1 also has a Remote Control mode, for working with either the wired or wireless (IR) remote control accessories. A two-second Remote mode enables a two-second delay between the press of the remote shutter and the time the camera takes the picture.
Sequential Shooting
Through the camera's Drive setting (which also accesses the Self-Timer and Remote Control modes), the E-1 offers a Sequential Shooting mode. Olympus states that the camera can capture approximately three frames per second, at the lowest resolution and quality settings, with a maximum of 12 frames in a sequence. While not as "deep" as the buffers on some professional SLRs, 12 frames is a pretty good-sized buffer, and three frames/second seems to be a pretty typical shooting speed among the majority of pro SLRs that I've tested. In my testing of the E-1, the camera did indeed capture a full 3.0 frames/second, and did so regardless of image size/quality/format setting. (That is, it captured 12 frames at a full 3.0 frames/second whether using TIFF, RAW or JPEG file formats.)
Flash
The E-1 features an external flash hot shoe as well as a PC sync socket for connecting external flash units. Though the camera does not offer a built-in flash, it does feature a Flash mode button, presumably for controlling the external flash unit's operating mode. Mode choices are Auto, Manual Auto, Red-Eye Reduction, Slow Sync, Slow Sync Second Curtain, and Fill for exclusive flash. Through the settings menu, you can also adjust the flash output, from -2 to +2 EV in one-third-step increments.
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