Sirius — manual-focus 80-200mm f/3.9 telephoto zoom sold across multiple 1980s SLR mounts
Sirius was a third-party lens brand marketed in the 1980s by independent distributors selling Japanese-made manual-focus zooms for the era's major SLR mounts. The 80-200mm f/3.9 was a mid-range telephoto zoom aimed at photographers wanting portrait-to-sport reach without buying primes.
The lens uses a one-touch push-pull zoom action, a macro-focusing setting common on zooms of this class, and an automatic diaphragm. Build is mostly metal and engineered plastic typical of 1980s independent zoom lenses. Exact element count, filter thread, weight and minimum focus distance are not confirmed from a verifiable source and are omitted.
Optical performance is typical of budget 1980s zooms: usable sharpness in the centre through the middle of the range, softening toward 200mm and at maximum aperture, with contrast and colour rendering below contemporary first-party lenses of the period.
These zooms are inexpensive on the used market and mostly bought for mirrorless adaptation or as budget telephoto options for film cameras. Check the zoom and focus rings move smoothly, confirm the specific mount fitted, and inspect for haze or fungus between elements.