I would suggest "Ordinary" or the normal position without any filtration because at least one position of the knob must be where there is no colour filtration.
Printable View
Just dug my pair out and it's dark here now, but looking at the ceiling lights, "Dark/Day, Green/Grey (can't tell now!), definitely Yellow and Flying10Uk is probably right about the "O" being "Ordinary" or something similar. That last setting is the closest to clear.
Some photos off an old drive, and my pair.
Well! I finally got my hands on them, and I'm gobsmacked! The lenses are in very good condition with no cracks or chips an even very few micro scratches on the lenses, either ocular or objective. The eye cups are excellent as well. They adjust as they should and the filters work just fine with good positive click into position. There are no graduations on the reticle so I doubt they were artillery or infantry use, but what do I know? My brother speculates that they were perhaps naval glasses. There is no date on them and oddly enough, no military acceptance stamp that I can see, but I don't know if that's unusual. Could these have been made for the civilian market? Here are some pics I took today, so enjoy.
My understanding is that 7X50 is pretty much a standard size binocular for hand-held marine use binoculars. Anything with larger magnification would not really be suitable for "hand-held" marine use because of movement of the boat/ship and would need fitting to a base/support. Obviously 7X50 binoculars are not just used for marine use and can, of course, be used on dry land where 7X50 magnification is required.
Thank you all for your input. I had the good fortune to communicate with a VERY knowledgeable gentleman in Winnipeg and I've got it nailed down. These are indeed a '42-'43 R.E.L. made set of 7 X 50's that had the filter carousel retro-fitted by B.O.P. in the early '50's. According to the gentleman I was to-ing and fro-ing with, they were almost exclusively made for the Canadian Navy. They are in excellent condition as is the case. The optics are very clear and everything works as it should. From their condition, I'd venture to suggest that if they were issued, they saw very minimal use and definitely no abuse. All of my questions have been answered. All in all, a very nice piece of Canadian military history.
Yours have certainly seen much less use than many. One thing lacking from our knowledge is the anecdotal reports of those who actually used the. Must be plenty of officers from the 50's still around.
"Royal Canadian Navy" that is...! ;)
lawrence_n, I've been using almost the same binoculars, but only thermal type. I think it should be like model AGM Protector TM50-384 ( found it here: https://www.аgmglobalvision.com/thermal-imaging ). But the main question for me is - what is better, night vision scope or a thermal one? Did you use both of them simultaneously?
I'd have to say that I find the REL 7x50s to be decidedly underwhelming and I have a pair that are more or less new in the case. They are like the 6x30s a rework of a US design I believe.
Some enterprising outfit in the Far East should start making a marine binocular with a built-in compass and these filters. Glare and eye-damage from it is a real problem at sea.