I've searched but can't find any commentary on... how does the 15mm limited compare to, say, the 16-45 or 16-50 at 16mm??

Does that 1mm make significant difference? And is the rendering of an f4 prime much different than the zooms at f4?

Not asking for zoom vs prime comments, just optical characteristics at (almost) similar focal length and same aperture. More subjectively, do those that have the 15mm feel it offers enough different optics than one of these zooms? thanks

[designinme_1976]

I had a similar situation comparing the two, and decided for the 15mm over the zooms. Now I don't actually have the 15mm *yet* - hopefully UPS brings it to me tomorrow. From my reading/research it seems the reason one would pick the 15mm over the zooms are .. ( and the reasons I went for it as well )

- Smaller size ( much smaller in fact )
- Punchier color straight out of camera
- Sharper wide open
- Better build quality ( compared to the 16-45 )
- Screw drive focus instead of SDM ( 16-50 )

The resale value for this lens holds up VERY well. The 16-45 doesn't. If you lean towards the zoom, I would suggest the 16-45 from the market place. Seems like a great lens to purchase used for the savings.

[twitch]

Have a look at photozone.de/pentax , all the lenses mentioned are test there for distortion, CA and shaprness.

There was a thread here a couple of months ago where someone showed the same scene shot @ 16mm with a 16-45, and @ 15mm with a DA15. From memory the scene was from the side of a hill looking down into a valley framed by a tree on the right side, sorry can't remember what the thread was though.