The Asahi Pentax 17mm f/4 SMC Takumar is an ultra-wide fisheye prime for the M42 screw mount, dating from the Super-Multi-Coated Takumar era of the early 1970s. It was designed to deliver an extreme angle of view on 35mm SLR bodies and is commonly paired with Spotmatic-generation Pentax cameras, though it adapts readily to modern mirrorless systems.

UK auction activity for this lens is thin: the three hammer results on file, all from 25 November 2025, each sold for £90, giving an identical low, high and median of £90 at saleroom level. Because these figures are wholesale auction hammers (excluding commissions), retail dealer asking prices in 2026 typically sit meaningfully above this band, and clean, haze-free copies with original caps and case tend to command the upper end of what the fisheye Takumar is worth today. Collector demand is driven by the SMC coating and the lens's reputation as a characterful specialist optic rather than an everyday wide.