Well, nearly. Thanks to reader Sven Bernert for pointing out a set of articles on the Carl Zeiss website which confirm that the lenses used in both the DSC-S70 (and we therefore assume S75 and CD300) and DSC-F505/F505V were designed by Carl Zeiss. "...multicoating guarantees vibrant pictures with superior definition and natural color rendition. With these features, the camera is sure to meet the demands of professionals and will even be used with enthusiasm by particularly ambitious photographers..."

From the Carl Zeiss website:

Carl Zeiss Vario-Sonnar® 2,8/7,1-35,5 lens for Sony digital still cameras DSC-F505 and DSC-F505V

The Carl Zeiss Vario-Sonnar® 2,8/7,1-35,5 lens is a high performance 5x zoom lens integrated with the digital still cameras Cyber-shot DSC-F505 and DSC-F505V from SONY.

The Carl Zeiss Vario-Sonnar® 2,8/7,1-35,5 lens is composed of 10 lens elements in 7 groups. Modern high-performance optical glass types are used throughout. Images are crisp, brilliant, and color is saturated due to Carl Zeiss multi-layer coating.

The optical design of the Carl Zeiss Vario-Sonnar® 2,8/7,1-35,5 lens is optimized for the filtering and protection elements of the Sony´s CCD. Optical performance is extremely high and evenly distributed over the entire image field, even with aperture wide open. So the full creative potential of this fast zoom lens can be used without technical constraints. During manufacturing Carl Zeiss Vario-Sonnar® 2,8/7,1-35,5 lenses undergo elaborate quality inspection including MTF (Modulation Transfer Function) measuring.

Carl Zeiss Vario-Sonnar® 2/7-21 lens for Sony digital still camera DSC-S70

The 7-21 mm Vario-Sonnar® f/2 lens from Carl Zeiss has been specially designed for the high-resolution 3.3 mega pixel chip used in the Sony DSC-S70 digital camera.This fast zoom lens provides an optical zoom range of 3x which corresponds to focal lengths of 34 mm to 102 mm in 35 mm photography. The lens is composed of 8 elements in 7 groups.

The use of 4 moving zoom groups and 2 aspheric elements in the 7-21 mm Vario-Sonnar® f/2 lens ensures that the lens displays exceptionally high image quality and well-corrected distortion over the entire zoom range. In addition, the Carl Zeiss multicoating guarantees vibrant pictures with superior definition and natural color rendition. With these features, the camera is sure to meet the demands of professionals and will even be used with enthusiasm by particularly ambitious photographers.

Phil: this adds further confusion into the mix, it's clear that the design of the lens used on the S70 is identical to that used on several other 3 megapixel digital cameras (Canon G1, Toshiba PDR-M70, Casio QV-3000EX, Epson PhotoPC 3000Z), however the current theory goes that only the Sony digital cameras can claim "Carl Zeiss" because of the glass / coating used... None of this is confirmed.