[bigben91682]

Yeah, and since that first post I re-ordered from amazon and got another $700 paper-weight. I've given up for the time being. Looking for a used one that has been tested but that may be a tall order, 'cause once you get a good one, why sell it??

[dmadden]

Thats annoying. Why dont u try sending it straight to the manufacturer? better off letting them fix it i tihnk. But is it sigma or tokina that made the lens for pentax?

[bentax]

tokina make a copy so maybe them?

are there any mailorder stores that will specially test a lens before they send it out?
if not, why not.

[aegisphan]

I don't see how the Sigma would make this lens, since this is co-designed by Tokina only.

As for me, I just ordered the lens together with the K20D. If my copy turns out to be bad, I think I would send it to Pentax for them to fix it. I've not heard any fail attempt from Pentax.

[dmadden]

I dont recall stating sigma or tokina as the manufacturer.
I do however recall asking who was

[300xcw]

I've received sn 9019439 in the last month from Adorama and have taken all sorts of shots from tripod on line drawings taped to the wall at different focal lengths and apertures and gone out and shot all sort of everything around the house at all different focal lengths and apertures. Since people seem to have problems with this lens I thought I would try some tests before I kept it. Did the ff and bf test and it came out perfect on the K10D at all lengths.

I have used the lens on a ist*DS and a K10D and have had all sorts of pictures from tack sharp to blurry. Some have distortion on the left and some don't. I'm keeping the lens because I've seen some very sharp shots, even at 16mm f2.8. 50mm f/2.8 works great too. I've also taken some blurry edge crap at both settings (even at high shutter speed). F/4 on up I get all sorts of results from reading DNA on a bug skin to "what's this a picture of?" . . . It seems to work much better with the istDS (gee, what's that noise??) than the K10D, not sure why. with the K10D it can take wonderful shots or crappy shots with the same settings, but it seems to have more crappy than good. I'm sure there's a truckload of operator error somewhere, but I haven't really figured out the intricacies of this lens yet. . . .especially from the K10D. Since I get some crystal clear shots from both camera bodies, I figure the bad ones are my fault, but I can't help but wonder why the shots from the istDS seem sharper.

The 50-135 I have is sharp everywhere on the K10D, it is almost too easy . . .

[Canada_Rockies]

I dont recall stating sigma or tokina as the manufacturer.
I do however recall asking who was

The design was done in cooperation with Tokina for a number of the lenses. If the lens on a Tokina advert has the same specs as the Pentax lens, it's the same optical formula. The Pentax lenses have the Pentax coatings. I have not seen both to compare mechanical build quality. Both my DA* lenses are great. Very happy with them. Lucky me. First try, too.

IMHO, if the lens were bum, I'd send it to Pentax and get it fixed right rather than hassle with trying out lens after lens.

[roentarre]

Da* 16-50 can be daunting with backfocusing on k10d. On k20d, it is actually quite a performer. I get less hunting with AF and it is becoming a pleasure to use.

[dugrant153]

I'm using it on a K100D, so the DA* is run on the screwdrive not the HSM. Mine has actually been refurbished and recalibrated by Pentax.

There's the occasional non-focus problems, but this one is definitely a lot better than the other 4 I tried, each one in different stores/conferences. I'm still really happy with it and it's 98% of the time bang on (and if not, I adjust with the manual focus ring). Coupled with the Pentax flash, this lens shines.

I've noted some purple-fringing (CA) wide open, and the F2.8 is a bit soft (nothing like my DA and M primes. those things are pretty sharp wide open) but overall it's still a good lens that can take good pictures. I've learned to live with it's faults so far....I consider them part of the character of the lens. But that being said, there are a few copies of this lens that seriously need some work (as was the case of the first 4 that I tested... and didn't buy).

[lithos]

I'm guessing it's a Tokina.

Hmmm. The Tokina even claims to have a special coating to repel "water or fingerprints."

It's sad that a flagship lens is actually, pretty much, not a Pentax save for a few bits on the outside. And, clearly this is something Pentax needs to address.

There're also a lot of lenses on the Tokina page that make me really wonder who's making them for Pentax - there's a 35mm f2.8 macro, a 12-24 f4 ultrawide, a 50-135...

Very depressing. Do Pentax still make any lenses? It seems a clear-cut case of dodgy outsourcing.

[flyer]

I'm guessing it's a Tokina.

Hmmm. The Tokina even claims to have a special coating to repel "water or fingerprints."

It's sad that a flagship lens is actually, pretty much, not a Pentax save for a few bits on the outside. And, clearly this is something Pentax needs to address.

There're also a lot of lenses on the Tokina page that make me really wonder who's making them for Pentax - there's a 35mm f2.8 macro, a 12-24 f4 ultrawide, a 50-135...

Very depressing. Do Pentax still make any lenses? It seems a clear-cut case of dodgy outsourcing.

As far as I can remember, Pentax as always outsourced the manufacturing of some of it's lenses, if not all.

[selar]

Looks like your lens has overcorrected spherical aberration/

[kent vinyard]

This is really interesting. Where have you guys been? It has been stated MANY times that the lens was co developed with tokina and manufactured in Pentaxes plant in Vietnam. My first copy had the usual problems of not focussing at the 16 to 24mm range. I had my dealer send it to Pentax for warrenty repair and 3 weeks later they sent me a brand new lens. This one seems to be steller.

[ricosuave]

hope you get a better copy.

[janneman]

I'm guessing it's a Tokina.

Hmmm. The Tokina even claims to have a special coating to repel "water or fingerprints."

It's sad that a flagship lens is actually, pretty much, not a Pentax save for a few bits on the outside. And, clearly this is something Pentax needs to address.

There're also a lot of lenses on the Tokina page that make me really wonder who's making them for Pentax - there's a 35mm f2.8 macro, a 12-24 f4 ultrawide, a 50-135...

Very depressing. Do Pentax still make any lenses? It seems a clear-cut case of dodgy outsourcing.

They just co-developed the formula. Two teams combining their knowledge and resources.
Then, each his own route, including construction. Pentax added SDM and kept the screw, Tokina got rid of the screw (at least the Nikon lens does not work on the non screw D40). Pentax added sealing.
And a star...
And a gold band...