Leica M Operating Instructions Manual page 126

EN
• The following can be used with restrictions
Despite the high precision of the range finder on the camera,
exact focusing with 135mm lenses with an open aperture
cannot be guaranteed due to the very low depth of field.
Therefore, stopping down by at least 2 stops is recommended.
• Possible, but excluded from the exposure metering
– Super-Angulon-M 21mm f/4
– Super-Angulon-M 21mm f/3.4
– Elmarit-M 28mm f/2.8 with serial nos. before 2 314 921.
122
Notes:
• The Leica Customer Care department can upgrade many Leica
M lenses with 6-bit coding. (Address, see p. 204).
• The use of Leica R lenses in conjunction with the R adapter M is
not expedient.