I have a pair of Carl Zeiss 8 X 30 jenoptem. Serial number 3710539. How old are they and what would be their approximate value? I can't find any info on them

fixya does not do appraisals.

They were made in 1979

http://www.europa.com/~telscope/zeissbin.doc

From this site

http://www.europa.com/~telscope/binotele.htm

Got from this site

https://www.birdforum.net/threads/carl-zeiss-binos-serial-numbers-list.105944/

From this search query after correcting your spelling

https://www.google.com/search?safe=off&rlz=1C1QJDB_enCA643CA644&sxsrf=ALeKk02gRMSoPXB3LEXi4JM23kb3qn8C6Q%3A1610920925119&ei=3bMEYKO_Bqyi5NoPrKCquAQ&q=Carl+Zeiss+Jena+Jenoptem+8x30w+binoculars+serials

..

If you are happy with the performance, why worry ?

It's 2017 - went up just over a week ago. Old Moore's Almanac will give you further details.

You likely have a set built between 1919 and 1930. If you go to this site (
The history of the telescope the binocular ) and scroll down (or search) to areas with Zeiss Binoculars, there are a number of files that have the information on runs. In my case, I looked at the Spreadsheet attached to the Zeiss Binocular Models entry, which , between lines 150 and 168, notes that binocs with the Lena logo were made from 1904 to 1945, and that serial numbers above 1 million began in 1919 and above 1,550,000 began in 1930, putting your pair in there more or less in the middle.

Cheers!

Google several vintage binocular web sites like this one:
http://www.collectorsweekly.com/military-and-wartime/world-war-two

and check Ebay for similar items.

Genuine CZ Jenoptems made in DDR have a 7 digit s/n.

Yours are probably made in Japan and may or may not be licenced by CZ Jena, Search on the web for fake jenoptems and all will be explained.

Genuine ones have 7-digit serial numbers, not 6, with no letters, so it's a good indicator that they are genuine. Yours were made in 1988.

Unfortunately if they are out of alignment you need to take them to a service center. It can't really be fixed at home without a device known as a collimator. Binoculars can fall out of collimation if they have been knocked or dropped. Jenoptems were made by the defunct East German Carl Zeiss Jena. Zeiss was split in two after WW2 with Jena being on the east. The current Zeiss firm is the West German company. Zeiss Jena ceased to be after the fall of the Berlin Wall. It is unlikely that the current firm would fix these for you. If they did the price would be greater than several pairs of Jenoptems.

Before you do take them check to see if they have a seven digit serial number. If it is six digits they are fake Jenoptems. There were many fake Jenoptems sold in the eighties by UK dealers. There is even a myth that they were made under licence in Japan. A myth is all that information is. There is no documentation to substantiate this and was probably spread by sellers trying to legitimise an inferior product.

take it into an outdoor shop and they can check the mirror alignment, seems that it may have "altered' itself