Carl Zeiss Jena blc Rm-F 12X60 für Em 4m R40 (View 1)
Manufacturer/Model: Carl Zeiss Jena blc Rm-F 12X60 für Em 4m R40
Field of View: 5 deg = 86.6 m/1,000 m; APFOV 60 deg
Weight: 5.4 kg
Exit Pupil: 5mm
Serial #/Year of Manufacture: 299584 = 1943-1944
Notes: Although the data plate is missing from the top of the binocular, the serial number, 299584, remains on the underside indicating (according to the production information in the red pages of Seeger’s grey book) it was one of a batch of approximately 1,300 marked: “blc X 5° Rm.-F 12X60 für Em4mR40”: blc = 3 letter wartime German coding for the manufacturer Carl Zeiss Jens; X = a lubricant coding; 5°= field of view; Rm.-F 12X60 für Em4mR40 = Richtungsweiser-Fernrohr 12X60 zum Entfernungsmesser mit 4m-Basis i.e.direction finder binocular for the 4 meter R40 rangefinder.
This 12X60 60° inclined binocular was used for sighting the Zeiss four meter R40 stereoscopic rangefinder which was equipped with three 12X60’s (see View 2: www.flickr.com/photos/binocwpg/9548682719/in/photostream/ ). They were also mounted on other model rangefinders and sighting devices and are found with variations in color (grey or tan), reticle type, regenrohre (rainguard/sunshield) build, and markings. Unlike the D.F.10X80 flak glass (see: www.flickr.com/photos/46330704@N08/6063248432/in/photolis... ), all blc 12X60 60° inclined binoculars had anti-reflective coated optics.
This binocular has some unusual and interesting features: 1. Interpupillary distance (IPD) is adjusted by moving a lever underneath the left eyepiece assembly which eccentrically turns the assembly to the required IPD (see: View 3: www.flickr.com/photos/binocwpg/9548678013/in/photostream/ and View 4: www.flickr.com/photos/binocwpg/9548671307/in/photostream/ ). 2. Each barrel uses an Amici roof and 60° deviation prism cemented together (see View 5: www.flickr.com/photos/binocwpg/9548656535/in/photostream/ ). This prism system has two air-glass surfaces instead of the four present on most Porro I and roof prism binoculars which improves light transmission for a brighter image. Also, it deviates the image to a 60 degree angle making it suitable for an inclined binocular such as this one. 3. There is a Farbgläser (colored filter) knob (A) above the left eyepiece which is adjustable for dark grey, light grey and clear settings (see View 5). 4. There is a fixture (B) above the right eyepiece for an attachment to illuminate the reticle (see View 2). 5. A metal quicksight (missing from this example – only its screws (C) remain) was fitted to aid in locating a target. 6) The faceshield (D) can be raised or lowered for correct eye relief by turning the center knob (E). Moreover, its rubber pads can be flipped to either side (see View 6: www.flickr.com/photos/binocwpg/9548644135/in/photostream/ ), or the entire shield can be folded fully upward for easier viewing. 7. There are Trocken luft (dry air) ports (F) on each side of the binocular for dry air purging. Also, near the front there is a plate (G) which was probably removed for desiccation purposes – most likely the insertion of a Trockenpatrone (silica gel desiccant cartridge). 8. The large knob at the front (H) tightens a clamp at the bottom for fastening the binocular to the rangefinder (see View 7: www.flickr.com/photos/binocwpg/9548627963/in/photostream/ ). 9. A long regenrohre (rainguard/sunshield) (see View 2) was attached to the front of the binocular. Many Rm-F 12X60’s such as this example are missing this part possibly because they were removed by soldiers for ease of packing in sending the souvenirs home after the war. On this example only the latch (I) for disengaging it to fold downward remains. 10. Not visible in the photograph, there are two circular covers on the lower right side below the right eyepiece - one behind and one to the right of it - which can be rotated to access a Robertson (square) screw in each. These screws are for centering the reticle (see View 3).
The optical performance of this binocular is, as with almost everything made by Zeiss during the war, excellent. Compared to the cxn D.F. 10X80 45° inclined binocular, its image is brighter, has much better sharpness to the edge and shows more detail having an extra 2X magnification. However, the D.F. 10X80 has the advantages of a much wider 7.5 degrees field of view and a larger 8 mm exit pupil. It has a quickly found and exceptionally easy view while getting a good view with the RM-F 12X60 involves (for me, at least) a lot of IPD and eye relief adjustment before it’s just right. Actually, I find it easiest to use when the faceshield is folded fully upwards as in View 3.
Seeger reviews this binocular on pages 226-227 of his book, "Military Binoculars and Telescopes for Land, Air and Sea Service” 3rd Edition, Hamburg, 2005, and in the same book on pages 248-249 there is an excellent description of its optical design written by Kevin Kuhne.
Note: If you have a vintage binocular you either wish to sell or would just like some information about, I can be contacted at flagorio12@gmail.com .
Carl Zeiss Jena blc Rm-F 12X60 für Em 4m R40 (View 1)
Manufacturer/Model: Carl Zeiss Jena blc Rm-F 12X60 für Em 4m R40
Field of View: 5 deg = 86.6 m/1,000 m; APFOV 60 deg
Weight: 5.4 kg
Exit Pupil: 5mm
Serial #/Year of Manufacture: 299584 = 1943-1944
Notes: Although the data plate is missing from the top of the binocular, the serial number, 299584, remains on the underside indicating (according to the production information in the red pages of Seeger’s grey book) it was one of a batch of approximately 1,300 marked: “blc X 5° Rm.-F 12X60 für Em4mR40”: blc = 3 letter wartime German coding for the manufacturer Carl Zeiss Jens; X = a lubricant coding; 5°= field of view; Rm.-F 12X60 für Em4mR40 = Richtungsweiser-Fernrohr 12X60 zum Entfernungsmesser mit 4m-Basis i.e.direction finder binocular for the 4 meter R40 rangefinder.
This 12X60 60° inclined binocular was used for sighting the Zeiss four meter R40 stereoscopic rangefinder which was equipped with three 12X60’s (see View 2: www.flickr.com/photos/binocwpg/9548682719/in/photostream/ ). They were also mounted on other model rangefinders and sighting devices and are found with variations in color (grey or tan), reticle type, regenrohre (rainguard/sunshield) build, and markings. Unlike the D.F.10X80 flak glass (see: www.flickr.com/photos/46330704@N08/6063248432/in/photolis... ), all blc 12X60 60° inclined binoculars had anti-reflective coated optics.
This binocular has some unusual and interesting features: 1. Interpupillary distance (IPD) is adjusted by moving a lever underneath the left eyepiece assembly which eccentrically turns the assembly to the required IPD (see: View 3: www.flickr.com/photos/binocwpg/9548678013/in/photostream/ and View 4: www.flickr.com/photos/binocwpg/9548671307/in/photostream/ ). 2. Each barrel uses an Amici roof and 60° deviation prism cemented together (see View 5: www.flickr.com/photos/binocwpg/9548656535/in/photostream/ ). This prism system has two air-glass surfaces instead of the four present on most Porro I and roof prism binoculars which improves light transmission for a brighter image. Also, it deviates the image to a 60 degree angle making it suitable for an inclined binocular such as this one. 3. There is a Farbgläser (colored filter) knob (A) above the left eyepiece which is adjustable for dark grey, light grey and clear settings (see View 5). 4. There is a fixture (B) above the right eyepiece for an attachment to illuminate the reticle (see View 2). 5. A metal quicksight (missing from this example – only its screws (C) remain) was fitted to aid in locating a target. 6) The faceshield (D) can be raised or lowered for correct eye relief by turning the center knob (E). Moreover, its rubber pads can be flipped to either side (see View 6: www.flickr.com/photos/binocwpg/9548644135/in/photostream/ ), or the entire shield can be folded fully upward for easier viewing. 7. There are Trocken luft (dry air) ports (F) on each side of the binocular for dry air purging. Also, near the front there is a plate (G) which was probably removed for desiccation purposes – most likely the insertion of a Trockenpatrone (silica gel desiccant cartridge). 8. The large knob at the front (H) tightens a clamp at the bottom for fastening the binocular to the rangefinder (see View 7: www.flickr.com/photos/binocwpg/9548627963/in/photostream/ ). 9. A long regenrohre (rainguard/sunshield) (see View 2) was attached to the front of the binocular. Many Rm-F 12X60’s such as this example are missing this part possibly because they were removed by soldiers for ease of packing in sending the souvenirs home after the war. On this example only the latch (I) for disengaging it to fold downward remains. 10. Not visible in the photograph, there are two circular covers on the lower right side below the right eyepiece - one behind and one to the right of it - which can be rotated to access a Robertson (square) screw in each. These screws are for centering the reticle (see View 3).
The optical performance of this binocular is, as with almost everything made by Zeiss during the war, excellent. Compared to the cxn D.F. 10X80 45° inclined binocular, its image is brighter, has much better sharpness to the edge and shows more detail having an extra 2X magnification. However, the D.F. 10X80 has the advantages of a much wider 7.5 degrees field of view and a larger 8 mm exit pupil. It has a quickly found and exceptionally easy view while getting a good view with the RM-F 12X60 involves (for me, at least) a lot of IPD and eye relief adjustment before it’s just right. Actually, I find it easiest to use when the faceshield is folded fully upwards as in View 3.
Seeger reviews this binocular on pages 226-227 of his book, "Military Binoculars and Telescopes for Land, Air and Sea Service” 3rd Edition, Hamburg, 2005, and in the same book on pages 248-249 there is an excellent description of its optical design written by Kevin Kuhne.
Note: If you have a vintage binocular you either wish to sell or would just like some information about, I can be contacted at flagorio12@gmail.com .