Hello, I can not share the criticism from Vorbewerter "behak". Bought over Hong Kong for 10 Euros this ring. When screwing the ring possibly the seat of a key ring file must od with fine sandpaper to be reworked. what can you expect for 10 euro already? But it is important to ensure the placing on the Objetiv sure that the aperture of the plunger is pushed Rollei lenses clean under the mounted metal tab of the ring, just so I can adjust the aperture. This ring has certainly aroused my beloved 135mm Zeiss Sonnar on my EOS back to life! If blurring occur at infinity, it may be due to the different focus distance between the Rollei film plane and the Canon EOS-CMOS. One can not always have everything for cheap!
