Ww_1 Binocular navy

[Erasmo]

Hello,anyone known a Pierre“Strembel Vendee”16x50 ?

[KizmeRD]

7 x 50 were standard Admiralty pattern. 
(There was a trade-off between magnification and susceptibility to shake due to engine vibration onboard ships).

MB

[Erasmo]

It's not from the navy, so ... I think it's French made anyway ... thanks for the clarification🙂

[MikB]

21 hours ago, KizmeRD said:

7 x 50 were standard Admiralty pattern. 
(There was a trade-off between magnification and susceptibility to shake due to engine vibration onboard ships).

MB

... and poor imaging at night from overmagnification of a 50mm objective's light-capture.

[KizmeRD]

Thanks for that added tit bit of information - I never tried using binoculars at night myself, but back in those days they wouldn’t have had night vision optics!

Anyway, clearly not naval binoculars, and obviously French manufacturer.

Apparently being offered on Ebay (auction ended today).

MB

[MikB]

56 minutes ago, KizmeRD said:

Thanks for that added tit bit of information - I never tried using binoculars at night myself, but back in those days they wouldn’t have had night vision optics!

Anyway, clearly not naval binoculars, and obviously French manufacturer.

Apparently being offered on Ebay (auction ended today).

MB

Just to be clear: I meant that 16x is too much magnification to get good image contrast in low light from a 50mm. objective. 7x50 is good, and is practically a worldwide standard for all-weather day and night marine use. High quality lens and prism glass can make only a marginal difference to this - it's a mathematical constraint.

[Erasmo]

Ok,7x50 it’s optimal in the navy...these is British navy binocular ? I do not know if is 7x50 or 6x30 🤔

[KizmeRD]

Who is the maker? What marks are displayed? 

There were thousands of binoculars made, for many purposes - not all are naval.

MB

[MikB]

7 hours ago, Erasmo said:

Ok,7x50 it’s optimal in the navy...these is British navy binocular ? I do not know if is 7x50 or 6x30 🤔

 

Because of the straight-through line from objective to eyepiece, and an apparent age that predates effective roof-prism instruments, what they look like is a Galilean glass with pretend prism cases to imitate prismatics. Magnification on these doesn't usually exceed 5x , and ~3x is more common. Diameter of the objective can be determined with a rule.

They can be a decent glass for users with myopia and some other eyesight issues, but it's not accident or clever advertising that made prismatics supersede them almost universally.

[KizmeRD]

Question for @MikB - Is it true that in-line Galilean binoculars were no longer that common in Royal Navy usage during the the Great War period?

On the other hand, as I understand it, army infantry units were still getting supplied with standard issue non-primatic binoculars (for general use), but with machine gun detachments and artillery spotters being issued the superior prism type. 

Army officers could of course purchase their own binoculars (and often did) - although wartime demand had caused commercially available binoculars to be in relative short supply.

MB

[MikB]

49 minutes ago, KizmeRD said:

Question for @MikB - Is it true that in-line Galilean binoculars were no longer that common in Royal Navy usage during the the Great War period?

On the other hand, as I understand it, army infantry units were still getting supplied with standard issue non-primatic binoculars (for general use), but with machine gun detachments and artillery spotters being issued the superior prism type. 

Army officers could of course purchase their own binoculars (and often did) - although wartime demand had caused commercially available binoculars to be in relative short supply.

MB

I don't know whether Galileans remained much in naval service.

There are plenty of photos of trench warfare in WW1 showing both types in continual use. Galilieans with big objectives and low magnification could still have useful value for night use.

All types of 'optical munitions' were in critically short supply, especially in late '14 - mid '15, and any official policies for supplying different branches of Army service with different types should be taken with a pinch of salt - the actual situation appears to have been more chaotic, with everyone using whatever they could get. It was even said that the War Office approached the German Government to purchase glasses! Many were purchased, loaned or donated from foreign (chiefly French) and domestic civilian sources, marked up with Broad Arrows, registration numbers and a 'Specials' grading system for issue.

[KizmeRD]

Thanks, plenty for me to still uncover and discover regarding the military's use of optical devices.

MB

[Erasmo]

so, it has a small magnification ... the creator is "prism" I think it is French, but are the lenses as good as those of "bausch & Lomb"?

[MikB]

On 16/11/2021 at 01:20, Erasmo said:

so, it has a small magnification ... the creator is "prism" I think it is French, but are the lenses as good as those of "bausch & Lomb"?

I'd agree it's French - Watson's book 'Binoculars Opera Glasses and Field Glasses' shows an extremely similar pair on p.19, described as dating from c.1910 and of only about 2x magnification, with imitation prism cases to look like more modern prismatics. If they are inscribed 'Prism' this would suggest either that they're deliberate fakes (legal constraints against such practices being quite sketchy around that time) or (very unlikely IMO) that they're an early model with Porro-Abbe or roof prisms. 

It's also unlikely the lenses match Bausch & Lomb's in quality - not only do the pressed and folded bridge components suggest cheap construction, but Galileans - if such they are - don't really require, and can't really make the best use of, very high quality lenses.

Edited 17 November , 2021 by MikB

[KizmeRD]

Seems likely to be ‘Prisma’ Paris (field glasses).

MB

[Erasmo]

Ah,I didn't know that at the beginning of the twentieth century there were already imitations ... but also military binoculars or only civil ones?  uhmm, it seems that prism-free binoculars were even worse than a telescope that perhaps had more magnification?  thank you both for the explanations, I learned good things about military binoculars 

[MikB]

3 hours ago, Erasmo said:

Ah,I didn't know that at the beginning of the twentieth century there were already imitations ... but also military binoculars or only civil ones?  uhmm, it seems that prism-free binoculars were even worse than a telescope that perhaps had more magnification?  thank you both for the explanations, I learned good things about military binoculars 

If they were military, they'd have an 'MG' (Ministere de la Guerre) marking, French equivalent to the British Broad Arrow. 

Imitations have been around as long as there've been visible characteristics identified with quality. At one time English potters were glazing red earthenware in white to imitate Chinese porcelain... 

Some WW1 writers, for example the sniper Hesketh Prichard, always preferred the telescope to binoculars for its far higher magnification, and greater length, permitting a steadier hold - the penalty of course being smaller field of view and more awkward handling.

Edited 23 November , 2021 by MikB

[Erasmo]

therefore, they were still current in ww-1, I think to observe from a fort, but the naval telescopes were longer than those supplied to the ground troops which had it seems to me only two elements against the five of the navy or was the opposite ?

[KizmeRD]

Telescopes went out of favour in naval usage once prism binoculars came in. If you were a ship’s lookout, or officer of the watch, it was far easier to scan the horizon with binoculars than with a telescope. The main advantages were greater practicality, increased field of view and depth of vision. Of course if you were only interested in a small objects, and you were already pretty sure where to look for them, then the greater magnification provided by a telescope still had its place - e.g. for navy signalmen who wanted to clearly identify a flag flying from the yardarm of another ship (and I guess similar may have been true for army snipers).

MB

[MikB]

13 hours ago, Erasmo said:

therefore, they were still current in ww-1, I think to observe from a fort, but the naval telescopes were longer than those supplied to the ground troops which had it seems to me only two elements against the five of the navy or was the opposite ?

By the early 19thC, most good telescopes for terrestrial or marine use would have at least 6 elements: a doublet or triplet achromatic objective, a 2-lens erector cell and a 2-lens eyepiece cell. The erector and eyepiece cells would typically be housed in separate brass tubes that screwed into opposite ends of the smallest drawtube. In prismatic telescopes and binoculars, the erector cell's function would be taken over instead by the prisms, which also could be used to shorten the instrument.

Powerful telescopes remained in use in navies not just to read signals, but to identify ships beyond the limits of binoculars. Telescopic functions were of course also incorporated in other instruments, such as rangefinders.

[Erasmo]

Hello,so the six elements were better than the three elements or if I understand correctly, the three elements had the roof prism?  but is it true that the naval telescopes were made of brass?

[MikB]

15 hours ago, Erasmo said:

Hello,so the six elements were better than the three elements or if I understand correctly, the three elements had the roof prism?  but is it true that the naval telescopes were made of brass?

Not necessarily to either question. Other prism configuration than roof prism exist, and in some cases carry out an erector function. There are many designs of telescope, especially astronomical, and hybrids incorporating features of more than one. It's worth the price and time to read a decent book on telescopes/binos and their development, and there are many of these.

Handheld naval telescopes tended to be made of brass because it's easy to shape, cut and machine, and it resists corrosion well if looked after. Another good material, lighter, stronger but more expensive, is cupro-nickel, also called 'nickel silver' or 'German silver' although it usually contains no silver. Steel is strong but heavy and rusts horribly in wet and salty air.

[Erasmo]

eh, yes, steel is more resistant than iron but it resembles it, but those with nickel were brass-plated, that is, in a brass bath or nickel was part of the copper + zinc

[Erasmo]

I would not have other questions but I still have a curiosity about my telescope: from the eyepiece side and not from the objective a sort of needle protrudes for about three mm ... what is the use?  thanks, to you for your patience😉

[KizmeRD]

Telescope eyepieces would normally have a focussing mechanism to allow small adjustment for the user’s eyesight. Without seeing a picture, I would guess that this is what you must be referring to. Is your telescope from the Great War period?

MB