100mm F2.8 W/R Macro

That's not bokeh though that's change, but it's great that there is prove I'm right for once, read my post above.

Only the highlights look rounder but if you look at what's further in the background then you won't see any difference so the difference in the out of focus blur is very minimal except for the highlights.

Interesting and quite impressive I must admit, but I guess my DFA 100 isn't suddenly performing any worse than it was

Thanks for the heads up Richard

You may recall that I recently did exactly the same as you! But I would never spend the asking price for the D-FA WR version , I will put up with 8 sided red LED's!

Someone has asked Dominique (tcom) to do some shots at smaller apertures than f4.5, maybe the results could be smoother :. I will do a test myself just to satisfy my curiosity as I've never really had any issues with my FA 50 macro which also has an 8 blade (non-circular) iris.

EDIT
Just tried smaller apertures, doesn't improve much, you have to shoot wide open to get a circular bokeh, even 1/2 stop down, you begin to see the shape of the blades, but that would be the same for any non-circular iris, even ones with more blades. Not a massive issue for me as I've always preferred the bokeh from the Pentax 100 compared to the Tamron or Sigma offerings. The new WR version just puts it into a different league for the same price as the non WR lens.

Maybe we could petition Pentax to introduce circular blades for ALL their lenses as I doubt it costs any more (judging from their own pricing)!

Can someone enlighten me as to the mechanical and image advantages of the * lenses?

From Pentax.com
"The tightly sealed, weather-resistant and dust-resistant construction enhances durability for use in both rainy and dusty conditions, making the DA Star lens a perfect companion for the weather-resistant PENTAX DSLR bodies."

Optically together with the limited range of primes they sit on the Pentax top tier

Thanks Greytop. So there is no specific optical advantage to a * lens, other than the practical benefits of improved weather resistance?

Like greytops says.

They are always the "pro" lenses, so wider aperture better optictical performance etc. and you pay for that.