7 lens elements in 4 groups with multi-coating offer excellent image performance with original and third party lenses. The teleconverter is mounted between the camera body and lens, transmits all exposure as well as distance data, and doubles the focal distance of the attached lens. A 75-300mm becomes a Super-Tele-Zoom with 150-600mm focal distance. With a length of only 43mm and a weight of 160g, the converter fits into any camera bag and is an ideal supplement for SLR equipment. When using the converter, manual focusing can become necessary (as of approx. speeds of 1:5.6-8) as 2x converters swallow 2 apertures of light from a physical point of view. The DG optimisation allows for best image results with digital as well as analogue cameras.