abstract:Low dispersion glass (LD glass) is a type of glass with low dispersion. Crown glass is an example of a relatively inexpensive low-dispersion glass.
It differs from its predecessor, the DP1x, because its lens now includes one "F" LowDispersionglass element to correct aberrations, and its resolution has grown by moving from Foveon's 14.6-megapixel APS-C size image sensor to the 46-megapixel APS-C image sensor found in the company's flagship SLR, the Sigma SD1 Merrill.
The use of Special LowDispersion (SLD) glass accompanied by aspherical lens elements not only compensates for a variety of aberrations, but also allows for a more compact size.