50-135 2.8 SDM

I would love to comply, but I have sold my K10D in the mean time and the K20D doesn't allow screw drive with the DA*s. I suppose I could block the powerzoom contacts by inserting some insulating material, but to be honest I prefer not to subject my lens to this.

I didn't note the exact observations.
Here's my review after some limited time with my DA*s:
http://wim-pentax.blogspot.com/2007/08/about-one-month-and-half-ago-i-ordered.ht...

My measurements were not scientific, they are just observations, but I compared extensively and the DA*50-135/2.8 hunting from infinity to closest focus matched up against my Sigma EX70-200/2.8 hunting up and down most closely. After the upgrade the comparisons were the same.

I would love to provide hard figures and facts, but you will have to take my word for it.

BTW, I'm really not alone in this statement. Other owners who tried have confirmed this. Pentax doesn't claim speed improvement either. I seem to remember reading this in an interview with a Japanese member of the engineering team behind the lenses.

Wim

I wasn't doubting your claim, but hard scientific evidence is always better than a personal impression.

I have the DA* 50-135mm lens too, and have no complaints about it's focussing abilities. So far, I've mostly used mine in a concert environment where the light is less than ideal. The lens performed very well.