| Version | Serial no | Date | Screws | Engraving | Notes
|
|---|
| F | 171011 < 171011 – 171721 > | Sep61 - 1963 | 0 | LMIJ | Early series has lens data on slanting ring which conflicts with photomic finders.
|
| F | 181011? < 181078 – 181562 > | 1963 - | 0 | LMIJ | Lens data on flat ring which clears photomic finder. New serial number block, start number possibly 181001 or 181011.
|
| F | < 181601. – 182640 > | - 1966 | 0 | LMIJ | Data ring with two small (screw?) holes following "50cm" and serial number. Most serial numbers followed by a dot.
|
| F | < 182841 – 183280 > 183318 | 1966 - 1968 | 0 | LMIJ | Focal length in mm but otherwise unchanged. Serial number appears continuous with previous version.
|