Should PENTAX make a prime lens of f/1.0 or faster? It doesn't have to cover full frame. Perhaps a lens like "
smc PENTAX-DA* 50mm f/0.9 ED AL [IF] SDM"? What is your opinion? Such a lens may be very expensive, and most of the super-high-speed lenses I have seen are for mounts with short back focus distances, such as rangefinders and mirrorless cameras, so such a lens would be very difficult to design for an SLR lens mount. Additionally, the depth of field would be extremely shallow wide open. It's not impossible, however, and if such a lens is built, it could be the standout lens for the K mount.
On a side note, the fastest aperture lens the KA mount contacts appear to allow is about f/0.85; see this
Bojidar Dimitrov article.
Last edited by bwDraco; 06-02-2011 at 11:36 AM.