Bought mine through B&H, it came today with a single piece of big bubble wrap around it in a very large box. So the lens itself had to have been clacking around the shipping box through shipment.
Tried it out. It is a small, light lens. Very similar in size and weight to the DA 18-135mm. My copy needed +2 AF adjustment no prob.
First impression, this lens sucks! And this lens also blows! No, really. When I turn the zoom ring, it sucks and blows air through the microphone port dramatically. If I unplugged the rubber port seal, I could probably clean dust off of lenses just by placing the dusty lenses near the microphone port of the K-1 and turning the 28-105's zoom wheel.
This is an issue with any non-internal focusing lens. It seems dramatic though with this 28-105 than my other lenses. Perhaps that means the weather sealing is decent-ish though. Both of the lens and in the K-1.
The extension parts of the lens also bind slightly in the middle of the zoom range. After watching it carefully, I can see they are slightly tilted upward maybe 1 mm at the most. Most people probably wouldn't have even noticed. It is a kit lens and it shows. But, for a kit lens, the IQ is nice enough. Not prime sharp, but I wasn't really expecting that. Still plenty of resolving power. Only minimal vignetting at 28mm and LR6 clears that away entirely.
And it seems at fastest aperture, there is a faint but visible dividing line in the frame of sharpness... somewhere around 2/3 to 3/4 out from center. That continues all the way to the corners which (the corners) are disappointing to me.
Used in crop mode that wouldn't be an issue as 1.5x crop would contain the entire 'circle' of sharpness.
I plan to take this lens out and test more... it might be going back for a second copy...
Anyone else experience the same things as I have with this lens? Anything else I need to look for while testing?