Nikon SB-29s Macro Speedlight system is designed for close-up flash photography in combination with Micro-Nikkor lenses. The SB-29s is an easy-to-use unit offering M1/32 flash output to assist in achieving the correct exposure using digital cameras with high sensitivity. It's electronic construction is of automatic insulated gate bipolar transistor (IGBT) and series circuitry. It has a flash coverage of 20mm to 24mm and film speed range in TTL auto flash mode of ISO 25 to 1000 (based on camera).