The EF-500 DG ST is Sigma's economical full-TTL flash, and has now been updated to also provide full i-TTL operation with the latest Nikon Digital SLR cameras (e.g. D70, D2-series).
Just as with many of Sigma's products, you will find features on the 500-ST that normally would only be associated with much more expensive flashes. The perfect economical all-around flash for any Digital or 35mm autofocus SLR shooter.
Bounce & swivel head
Flash can be tilted 90° upwards and 7° downward for close-ups. Also can be swiveled 180° to the left and 90° to the right
AF Assist
Autofocus auxiliary lamp helps the camera to focus in low-light situations.
Auto Power Off
Battery-saving mode shuts down power after 80 seconds.