Olympus C-4040 ZoomOlympus introduces a top-of-the-line 4-megapixel model with noise reduction technology, optimum image enlargement, and newly designed interface<<Viewfinder :(Previous) | (Next): Exposure & Flash>> Page 5:OpticsReview First Posted: 07/23/2001 |
Optics
The Olympus C-4040 Zoom provides an all-glass, aspheric lens design, with 10 elements in seven groups. The 3x, 7.1-21.3mm lens provides a focal range equivalent to a 35-105mm zoom on a 35mm film camera. We were very pleased by the speed of the lens (measured by its maximum apertures), which was an impressive f/1.8 at the wide-angle setting, and f/2.6 at telephoto. This doubtless contributed to the excellent low-light performance we experienced with the C-4040.
Focusing distances range from 2.6 feet (0.8 meters) to infinity in Normal mode, and 7.8 inches to 2.6 feet (0.2 to 0.8 meters) in Macro mode. The macro focusing produces a minimum capture area of approximately 3.5 x 2.5 inches, about average among top-end digital cameras we've tested. Autofocus is determined through the lens, using a contrast detection method. This means that the autofocus will work properly with auxiliary lenses. The green LED next to the optical viewfinder glows solid as soon as the subject is in focus (flashing means there's a problem focusing and you may need to switch to Manual Focus or Macro mode). Though the C-4040 doesn't feature an automatic focus lock, you can manually lock it by centering the target portion of the subject in the frame, pressing the shutter button halfway, and then recomposing the image while continuing to hold the shutter button halfway.
The C-4040 Zoom's Manual Focus mode is activated by holding down the Menu button for approximately one second, until the focus distance scale appears on the LCD monitor. By pressing the Right Arrow button, and highlighting the MF (manual focus) icon at the bottom of the scale, Manual focus is engaged, and you can then use the Up and Down Arrow buttons to focus. As you focus, the image is automatically enlarged in the LCD monitor to better see small details. You can save the focus setting by pressing and holding down the Menu button for one second, and likewise, cancel the saved setting in the same manner.
You can opt to keep the camera in continuous autofocus by activating the Full-Time AF mode in the Shooting menu. Full-Time AF means that the autofocus is constantly engaged as you move the camera from subject to subject, instead of waiting for the shutter button to be depressed halfway. This is useful for action photography like fast-paced sports or children playing, but it is an additional drain on the battery because the focusing mechanism is constantly at work. (We also didn't find that continuous autofocus made for a dramatic improvement in shutter delay.) You can also designate whether the camera determines focus from the center of the image (Spot) or the entire image area (iESP), by choosing the appropriate AF Mode option in the Shooting menu.
The C-4040 Zoom's exterior lens barrel incorporates 41mm filter accessory threads that couple to Olympus' lens adapter tube, the CLA-1. This optional adapter extends the threads outward (and increases their diameter to 43mm), so they are flush with the front of the lens when it's fully extended. It's important to note though, that this adapter is made to work with Olympus' own accessory lenses, all of which use an additional adapter ring to step up the threads to the diameter needed by the auxiliary lenses. The consequence of this is that the CLA-1 design requires another threaded adapter ring, because it doesn't extend far enough for 43mm filters to clear the lens barrel. The 43mm filters will interfere with proper lens operation, and could damage the lens mechanism itself! Therefore, if you buy a CLA-1 adapter unit, be sure to also buy a step-up ring to whatever filter size you use, just to give you the extra millimeter or two necessary for the lenses to clear the front of the lens barrel.
The C-4040 Zoom also provides up to 2.5x Digital Zoom, which must be turned on in the Shooting menu. Once activated, a Zoom scale appears on the left side of the monitor. The bottom half of the scale (colored white) indicates the optical zoom, while the top half (colored red) specifies the digital zoom. The Digital Zoom is only accessible when the LCD monitor is engaged; when the LCD is turned off, the zoom returns to the 1x setting. It also cannot be used with the uncompressed TIFF mode.
Though we are very impressed with the low-light capabilities of the C-4040 Zoom, one consequence of the unusually "fast" lens design is that optical distortion is rather high at the wide-angle end, where we measured approximately 1.0 percent barrel distortion. The telephoto end fared much better, where we found approximately almost no pincushion distortion. Corner sharpness also suffers a bit at wide-angle, and chromatic aberration is a little higher than average. All forms of distortion improve markedly toward the telephoto end of the lens's range. Center resolution is very high, easily extending to 900 lines per picture height in both horizontal and vertical directions, and with strong detail visible all the way out to 1,200 lines on our resolution target.
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