[Blue]

"This here is the most powerful hand holdable Pentax lens made. It can take the picture of a man's head 3 blocks away."

[Eastern Shore Charlie]

I bought both the *50-135 and *16-50. For a moment I was on top of the world with some fine Pentax glass in my camera bag. I had 2 16-50's both had focus issues and were sent back to Pentax service and they replaced them. The SDM died on my 50-135 and sent back to Pentax service and they replaced it too. After reading all the issues people where having with these lenses I sold both while they where still working fine. The 16-50 I do not miss, but I cried having to sell the 50-135. No choice knowing that it only had a year warranty.... I did not trust the SDM. I did learn Pentax service is the best when dealing with these types of issues and how they replaced the lenses without any hassles and taking months to make the decision to replace. Just finished fighting with Sigma for 6 months over a soft focsing lens that was not sharp at any f stop. Pentax service is the best.

[Blue]

Charlie, there are people that had problems with the Sigma HSM.

[brecklundin]

The opposite is actually true.
Better equipment makes better pictures, no matter what the skill level of the photographer is.

in this case "better" being a completely relative term...

[brecklundin]

I guess Dell did something to correct those problems. we just hope that Pentax does the same instead of ignoring it.

yeah, they convinced Michael Dell to come back to work and fired the current CEO. hehehehe....I too was one of those who, for years bought Compaq laptops then their build quality dropped and Dell became super, then they turned to crap (I too had three consecutive bad laptops from Dell), so, I switched hack to the HP/Compaq business builds for my last two.

The thing about Dell's situation was they went public with exactly WHY they made the change, acknowledged that quality had dipped, apologized about the off-shoring of consumer grade systems support (business support stayed in the US)...but they made public, very public, changes. But it was not enough to win me back. I burn through over $12,000 on three bad laptops, it's hard to convince me I can trust them again that they are no longer building laptops based on the fact many users would buy the 4-yr warranty so they build quality could be marginal and probably looked better on the quarterly reports but on longer term the costs for repairs had to eventually catch up with them. But, no, I will likely never buy another Dell product all because of a short 7yr period.

I feel Pentax needs to at least set things straight publicly on the SDM front, being burned once, I don't feel comfy spending near to a grand or more on a lense which may or may not last more that weeks beyond the warranty, of that long. And it is a shame because every one of the DA* lenses are superb in their class. But, these days money is harder to get, and products seem to be less well made, photography is a hobby for me though I also use it for business, so I need my lenses not seem to need an expiration date.

I bet if Pentax came out and just offered a 3yr warranty on the whole SDM line then offered existing owners an added two years they could instill trust for many of us.

Also, it seems to have gone over-looked in this thread, but to those naysayers, if there was not a real problem WHY would Pentax be so willing to just replace DA* lenses without the usual 3-4 trips to the shop most other MFG's will need before you can convince them you have a lemon.

Me? I think this PMA there might be an interesting announcement about Pentax itself...but that is better to the rumors sort of forum...

[Photomy]

I think SDM is reasonably fast. The only thing is it doesn't feel USM fast/quiet. Back when I owned the Canon 30D and a few lenses (among them the 28-70mm f/2.8 L and 35-90mm $20 cheap lens) I never noticed how fast Canon USM was (b/c in reality it WASN'T "fast" compared to my 50-135mm). The big difference was was how quiet and accurate the AF was. My 50-135mm would occasionally hunt around in doors (even outdoors it is EXTREMELY occasional). Also, SDM isn't super quiet at all. It may be much more quiet than the scratching sound of screw AF, but compared to USM (even non ring USM), SDM is comparatively loud. Don't get me wrong, it doesn't bother me at all, but it seems strange that Canon has had this technology since the 199 something and Pentax is only just starting to use it and even this technology is inferior to the super old 28-70mm i use to have.

I still have no idea why Canon USM is so fast...

I have never had a real problem with SDM before, but I have had to service my 50-135mm due to a loose MF ring. I later found out you can tighten this yourself...
I would still recommend it. If you have never tried USM before, then SDM should seem pretty fast/ quiet.

The AF hunting could just be my camera body though... the 30D apparently had super fast AF system.

I believe that Canon developed ring USM technology early on and it was a major step forward. They then committed simultaneously to changing their AF system around this and the mount to fully take advantage of the fully electronic EOS system. It was a gamble to piss off all of the FD mount customers, but it was such a good new system and AF was clearly the future at that time, they went forward with it. The rest is history and some companies are still playing catch up.

[PentaxPoke]

I believe that Canon developed ring USM technology early on and it was a major step forward. They then committed simultaneously to changing their AF system around this and the mount to fully take advantage of the fully electronic EOS system. It was a gamble to piss off all of the FD mount customers, but it was such a good new system and AF was clearly the future at that time, they went forward with it. The rest is history and some companies are still playing catch up.

Agreed. EOS was introduced in 1987. Canon basically went "all in" with the electronic lenses. Motorized focus, motorized aperture, etc. If you look at an EOS lens, you will see there are no mechanical connections at all. Canon camera bodies have no aperture or screw drive motors. Everything is done in the lens. It was a gamble but it paid off big-time. Especially with the ring-USM. If you have ever tried a ring-USM lens, you can tell the difference immediately.

I think this is where Pentax is having difficulty. They are literally 20-years behind in lens-motor implementation. And when they did decide to implement lens motors, they did it in a compromised way in order to allow older camera bodies to use newer lenses. Personally I think this was a big mistake. I can understand the desire to have newer bodies, use older lenses. All that takes is to add a motor to the body so that screw drive can be used. But the other way around is problematic. Glass is made to last. People change bodies all the time. I would have liked to see SDM done right (ring-type), and starting with the DA* lenses, only new bodies with SDM electronic connections could use the new lenses. Had Pentax done that, I doubt there would be this SDM "disaster."

IMO, as long as Pentax continues to use SDM micromotor-gear drive lens focusing, it will never approach the reliability and speed of the competition. The competition only uses that method in the cheapest kit-lenses.