Originally posted by Caat I wasn't trying to argue that Pentax chose to start at 28mm because they didn't want to follow the crowd. I was suggesting that there are considerations around it that are different for Pentax than for Canon (for example), including 28mm being easier to design at a higher level of performance than 24mm, Pentax having more limited resources and less recent 35mm lens design experience and a need to time the lens release with a major camera announcement (the K-1).
Of course, in an ideal world I am sure Pentax would have loved to have produced a 24mm to 100mm+ lens at that point in time.
Yep.
When you choose to do 24mm instead of 28mm, that's got a big impact on image quality.
Distortion and vignetting on a full frame lens are higher, the light is no longer just coming in parallel to the ground. Wide angle lenses are harder to design than teles. The customer will have to pay for the engineering to make it any good - often size as well as dollars.
APS-C is the same story. Nikon and Canon know all this and their kit zooms are 18mm, not 16mm.
Back in the 35mm film days, a standard trio of lenses was the 28mm, 50mm and then something like an 85, 105 or 135mm.
I have the 28-105, and it's a pretty amazing lens we Pentaxians have available to us.
It's so good - sharp, fast and silent AF, WR, nice size - it possibly cannibalizes sales of the professional 24-70 f2.8. Great for us buyers, not great for Ricoh.