2Wire E-100 ZOOM RSOl manual Importance of Match- ing Lens to CCD

The Importance of Match- ing Lens to CCD

More than 200 years ago, Newton showed that white light was composed of multiple wavelengths, (RGB) which are now called photons. These waves of light pass through a lens on a camera and are supposed to be “imaged” at the same point, onto film emulsion for example. When the pho- tons are not imaged properly onto the film plane, chromatic aberration occurs and is most commonly caused by using single lens construction. Incorporating two lenses made of different materials can solve chromatic aberration with film camera lenses. The net effect of chromatic aberration is un- intended color artifacts such as halos and wild colors.

The marriage between lens and CCD is critical to delivering the best possible images. Post imaging processing can only do so much to help a poor image. Remember the old axiom, garbage in - garbage out.

The same holds true for uncorrected lenses made for digital cameras and the net effect it causes are unwanted artifacts, noise and a degraded image. Unbeknownst to many in the industry, digital camera lenses require different construction than film camera lenses. If a manufacturer, (and some do) tries to place a lens designed for a film camera onto a digital camera, the net effect is chromatic aberration and only a small portion of the lens will actually throw light onto the CCD. This gross under-utilization also causes a loss in edge-to-edge sharpness that could be delivered to the CCD.

The digital camera lens construction of the CAMEDIA E-100 ZOOM RS contains a concave element that forces photons coming through the lens into a straight-ahead alignment to the 28 MHz high-speed progressive scan CCD. All CCD sen- sors are very picky about how light is delivered to them and they don’t like oblique angles of light hitting them, which

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causes a digital form of chromatic aberration. Film emulsion layers are designed to read light from an oblique angle and the fall-off from the lens. Olympus found that in order to get the best possible images from a digital camera, the light coming into a CCD must be straight on.

The CAMEDIA E-100 ZOOM RS Lens

Elements and Interaction with the CCD

Lens Elements

Film

Emulsion

Layers

Lens Elements

CCD￿

Sensor

Light - Photons