This brand new Macro Extension Tube Set for M42 (42mm x 1.0) screw mount includes 3 extension tubes – 7mm, 14mm, 28mm adapters. You may mount the tubes between lens and camera body to get your choice of macro ranges. There are totally 7combinations.
Use this set will not downgrade the optical quality of your lens. Sharpness and Saturation can be still maintained. But they are not meter-coupled. They do not preserve the automatic diaphragm. It should be used with manual lenses with their own aperture dial.
When using the extension ring with a M42 body, the camera should be set in the ‘M’ mode.
It work with all M42 mount cameras