the new ELECTRONIC FLASH MACRO EM-140 DG. ELECTRONIC FLASH MACRO EM-140 DG is designed to work with both AF 35mm film and Digital SLR cameras of all-popular manufactures. The EM-140 DG Ring Flash is ideal for photographing subjects in fine detail when the shadowless mode is used, and is extremely effective for scientific and medical applications. Dual flash tubes can fire simultaneously or separately. Using only one flashtube creates modeling, which can give a three-dimensional feeling to the subject. The flash features a guide number of 14 w/ISO 100. The Modeling Flash function makes it possible to check for reflections and shadows before actually taking the flash picture. Compatible with Nikon D-TTL & i-TTL standards.