Pentax DA 40mm F/2.8 SMC

The Pentax DA 40mm F/2.8 SMC is only 15mm in length and, incredibly, only protrudes from the body a bit more than a standard body cap would normally do! 

The Pentax DA 40mm F/2.8 SMC focal length transfers to a film-equivalent focal length of 60mm on a Pentax D-SLR, so it’s a little longer than you’d expect with a standard prime. While not quite pocketable once on a D-SLR, the combination of the two (even with the Pentax K-7) makes it a very neat proposition.
The Pentax 40mm features a maximum aperture of f/2.8, so it’s quite fast. The build quality is excellent – with the majority of the construction metal, including the lens hood and lens cap.
AF is pretty quick and locks on without hassle, but as there’s no AF motor, it’d be fair to say that there’s quite a bit of AF buzzes and whirrs during operation. 
As you’d expect from a lens only 15mm thick, the manual focus ring is thin, but it’s very finely grooved and the balance is perfectly weighted for control – and very satisfying to use.

www.pentax.co.uk