Jesse Ashbridge House, built in 1854 -- NEX-5 & Pentax-K 28mm f3.5. Click to see larger.
I think I wrote many times that I love the small and beautiful early Pentax lenses, especially their screw mount version. This bayonet K-mount 28mm f3.5, probably inherits the same design as the M42 SMC Takumar 28mm f3.5, but has a 52mm filter size, versus the 49mm of the M42 version. It's also quite a bit larger. Both of them have exceptionally sharp optics. I also used the SMC-A version of the 28mm f2.8, but prefer this lens. It's sharper, better made, focuses silky smooth like the M42 Takumars.