An Unusual Barr & Stroud CF5 Binocular

Here is an interesting pair of Barr & Stroud binoculars. The model is CF5, but it does not correspond to either of the two CF5 models described in William Reid's We're Certainly not afraid of Zeiss¹, and has some of the features associated with each. 

Two Documented CF5 Models 

The CF5 was the only B&S binocular model designation that was used for more than one distinct binocular model. Reid¹ details two CF5 models:   

The first is a CF5 Porro-I 8x0.9inch (23mm) model, which is one of the 'first eight', and is the central focussing version of the CF7.

The 'first eight' porro-prism binoculars made by Barr & Stroud, (CF1-CF8), were produced, beginning in 1919, and continued in production until the end of the 1920s. The B&S logo, shown here on the left, was engraved on the metal prism cover.

The distinguishing features of the 'first eight' models, compared to later models are: metal prism covers; the B&S logo shown above on the left; a knurled knob at the base of the hinge pillar, used to loosen/tighten the hinge for adjustment of the interpupilary distance; the binocular strap is attached to a single metal loop/slot on each of the two binocular barrels. The 'first eight' CF5 looks similar to the CF1 pictured here on the right.

The second CF5 model is a Porro-I 6x24, pictured on the left here, which replaced the CF1, and was the central focussing version of the CF19, with a field of view of 138 yards at 1000 yards. It was introduced in 1929/1930, and continued in production until 1962.

The distinguishing features of this later model are: Bakelite prism covers; the molded B&S logo shown here on the right; no knurled knob to tighten the central hinge pillar; the binocular strap is attached by two loops/slots on each side, one molded into the edge of each of the upper and lower bakelite prism covers.

An Undocumented CF5 Model? 

This unusual Barr & Stroud CF5 model binocular, recently acquired at auction, differs from the two documented models described above, in several important respects: 

This central focussing model is 6x23, and has no serial number that I have been able to find. The field of view is 8^o (140 yards at 1000 yards). It has Bakelite prism covers (similar to post-1929 models), but the embossed logo is the same graphic design as those of the 'first eight'. Sadly, on this binocular, the top right hand prism cover has broken loop for the binocular strap. 

The left Bakelite prism cover has the circular B&S logo, around which is marked Barr & Stroud Ltd. Type CF 5. 

The right Bakelite prism cover is marked Glasgow & London around a circle enclosing the words 6 x 23 O.G. 8^o. 

The oculars appear similar in design to those of the 'first eight'.The hinge column is similar design to those of the 'first eight', including a knurled knob to tighten the hinge.

The case looks as though it may have been made by B&S, but does not have the usual mark of the company name.

It looks to me as though it is a modified first-eight CF1 design with the metal prism covers replaced by Bakelite ones, and with no strap hoops on the barrels (strap hoops integrated into the prism covers instead). If that's what it is, it could be a prototype for the later CF5, which replaced the CF1. If so, it is likely to be dated c1929, during the redesign from the earlier CF1 6x23 to the later CF5 6x24. In any case, it appears to be a (possibly unique) ex-production model.

If you have any more information about this unusual pair of binoculars, please let me know in the comments below, or contact me by email (see 'Contact' tab).

For more information about Barr & Stroud, and many other optical instrument makers throughout history, please see reference 2.
 

References

(1) We're Certainly not Afraid of Zeiss. Barr & Stroud Binoculars and the Royal Navy. William Reid. National Museums of Scotland Publishing Ltd., 2001. ISBN 1-901663-66-3.

(2) Brass and Glass: Optical Instruments and Their Makers. Tony Benson. 2024. ISBN 978-0957652774.

All photos and text are © copyright Tony Benson, not to be re-used without permission.