I was wondering if there is a site and/or someone who knows about future plans of Pentax about this system. In particular, I am very interested in knowing what are the next lenses Pentax is designing (I know two new ones are just come out, but am very curious) and if Pentax is going to address in some way one of the major issue of this system , shallow DOF . I don't know why no wide angle lenses can be stopped down beyond f:22 and why Pentax does not manufacture at least ONE tilt/shift lense for its system. The 75 shift is my opinion rather limited (architecture needs wider focals) and I think there's room for a 45 or 55 tilt/shift version. Although the cost of such a lense would be comparable to an entire 4x5 system, one could put up a system that would cover 99% of the needs of a landscape photographer.

-- Roberto Manderioli (rmander@libero.it), January 29, 2002

Answers

Roberto, I have made suggestions to Pentax about new lenses but heard nothing from them. The 55-100 zoom has f/32 at all focal lengths so it will do 3 1/2 feet to infinity at 55mm at f/32. This is an improvement over the existing wide lenses but you're right, the DOF issue is one that Pentax needs to address further. The 90-180 zoom has the right idea with its f/45. Going to f/90 or f/64 causes too much diffraction for 6x7 film size. 4x5 can get away with it due to the larger film.

-- Steve Rasmussen (srasmuss@flash.net), January 29, 2002.

Also concerning future lenses, I have designed a 35mm rectilinear aspheric lens as a suggestion to Pentax. It is a preliminary design and does not have glass types or surface radii but is a cross section showing the elements and types of sufaces when aspheric. I will send it to them soon.

-- Steve Rasmussen (srasmuss@flash.net), February 18, 2002.

How about a Quartz/Fluorite 55mm f/4 Ultraviolet lens. That would rock!

-- rolland elliott (rolland_elliott@hotmail.com), February 21, 2002.