SMC Pentax-M 28mm f2.8 brand_Argus This model features mirror lockup

This model features mirror lockup for steadier long-exposure shooting (Pentax 67 shutters are notoriously jostly)

and shutter speeds are good

It has a convenient accessory shoe for a viewfinder (viewfinder not included) and a 1/4" threaded tripod attachment point on its base

The Tamron Adaptall 28mm f2

SMC Pentax-M 28mm f2.8 brand_Argus This model features mirror lockupThe SMC Pentax M 28mm f2. 8 is a compact wide angle lens that's about the same size as the standard 50mm lens but with a substantially wider field of view. Great for groups and architecture, with a still pretty fast f2. 8 aperture. In excellent condition, with minor cosmetic wear, clean glass with light dust.