You should be pleased with this lens. The black ones are of later manufacture (yours was made in 1977 as you can tell from the serial number) and usually do not require focus mount relubrication. The J-8's accept the plentiful 40.5 mm filters, a bonus.
The Jupiter-8 lenses seem to be among the more trouble-free of the Russian lenses, particularly with regard to focus problems.
Enjoy using your J-8, it is a fine, sharp lens. You will continue use it, even if you should later add an additional 50mm.
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