Digital Camera Home > Digital Camera Reviews > Toshiba Digital Cameras > Toshiba PDR-M71

Toshiba PDR-M71

Toshiba introduces a feature-packed, value-priced 3 megapixel model!

<<Viewfinder :(Previous) | (Next): Exposure & Flash>>

Page 5:Optics

Review First Posted: 08/24/2001

Optics
A Canon 2.8x, 7.25-20.3mm zoom lens is built into the PDR-M71, the equivalent of a 35-98mm lens on a 35mm camera. Aperture can be manually or automatically adjusted from f/2.9 to f/8. The PDR-M71 employs a contrast-detection autofocus mechanism, with a focal range from 2.7 feet (80cm) to infinity in normal mode, and from 4 inches (10cm) to infinity in Macro mode. A Focus button on the back panel accesses the Macro mode, as well as three fixed-focus settings (1 meter, 3 meters, and Infinity). Though the PDR-M71 does not feature a focus lock button, you can manually lock focus by pointing the center of the frame at a specific part of the subject and depressing the Shutter button halfway, then reframing the subject while keeping the Shutter button halfway depressed. This locks focus and exposure until the Shutter button is either fully depressed or released.

In addition to the PDR-M71's 2.8x optical zoom, the camera also features 2.2x Digital Zoom, which is enabled through the Recording menu. Once activated, Digital Zoom is controlled with the Zoom rocker button on the back panel. Digital zoom is accessed by zooming past the normal telephoto range, which is indicated on the LCD monitor by a progress bar (the digital zoom portion is displayed in red). We always remind our readers that digital zoom is merely enlarging the center portion of the CCD, which decreases the overall image quality with excess noise and / or lower resolution.

Optical distortion on the PDR-M71 is a bit better than average at the wide-angle end, where we measured an approximate 0.65 percent barrel distortion. The telephoto end fared much better, as we found only one pixel of barrel distortion (about 0.05 percent). Chromatic aberration is a bit higher than average, showing about 3-4 pixels of red coloration and 5-6 pixels of green coloration along the target lines. (This distortion is visible as a very slight colored fringe around the objects at the edges of the field of view on the resolution target.) Overall, we'd say that the PDR-M71 has a fairly good lens, but it's plagued by excessive chromatic aberration and some softness in the corners.


Reader Comments! --> Visit our discussion forum for the Toshiba PDR-M71!



<<Viewfinder | Exposure & Flash>>

Follow Imaging Resource: