Trinol — budget M42 105mm f/3.5 telephoto prime from a minor 1970s catalogue brand
Trinol was a minor third-party lens brand of the 1970s, distributed through photographic mail-order and department-store catalogues alongside numerous similarly obscure rebadged Japanese lens lines aimed at budget-conscious SLR buyers.
The 105mm f/3.5 is a moderate telephoto prime typical of the period, built primarily in M42 screw mount with a preset or semi-automatic aperture mechanism common to budget lenses of this class. Construction is mostly metal, with a manual focus throw typical of 1970s telephoto primes.
Optical performance is modest by design, with softer wide-open rendering and lower contrast than first-party 105mm lenses of the same era, improving when stopped down to f/8. It is not a lens noted for distinctive character so much as affordable telephoto reach.
Surviving examples are uncommon and typically found only in secondhand job lots rather than through dedicated dealers, reflecting the brand's minor market presence. Buyers should check the aperture mechanism operates smoothly and that the mount threads are not cross-threaded or damaged.