A non-optical device that increases the distance between the lens and the film
This allows the distance between the lens to focus much closer than normally possible and thus, gave the increased magnifications
For Canon EOS camera owners keen on shooting close-up pictures even if they don't have a bellows unit or any of the three Canon EF Macro lenses
Adds just over 25mm of extension
The EF 25 tube is provided with a set of EF lens contacts that allow shooting data to pass between the lens and any EOS camera body. All camera exposure modes can be used but spot metering is not possible