[david94903]

Well my SDM failed again, after the warranty was up of course. Back to manually focusing with my 16-50. I think rather than spending another $200 fixing the lens, I'll spend a $100 on a Katzeye split screen (I put one in my K20d and it was great - eliminated all the front focus/back focus issues that the camera had) and just keep it a manual focus lens. I'm keeping away from the SDM lenses, I don't trust them.

[woodywesty]

Well my SDM failed again, after the warranty was up of course. Back to manually focusing with my 16-50. I think rather than spending another $200 fixing the lens, I'll spend a $100 on a Katzeye split screen (I put one in my K20d and it was great - eliminated all the front focus/back focus issues that the camera had) and just keep it a manual focus lens. I'm keeping away from the SDM lenses, I don't trust them.

That REALLY sucks! Seems like I read on the forum that Pentax had redesigned/fixed the bad parts in the lens so that they wouldn't fail?? Maybe that information was incorrect. This is unfortunate for me as well because I've been seriously considering the 16-50 as my main lens. Now I'm not so certain. Would be nice if Pentax would offer a multi year warranty for their SDM lenses for a little more money. I'd be tempted to call the Pentax offices in Denver and raise holy hell!

[david94903]

It is a great lens, the IQ wonderful, and the focal range is really great too. I have a Nikon buddy who has a similar Nikon lens and he can't get to the same level of IQ on his. Makes him crazy because he paid quite a bit more than I did. I really love it. I'm just bummed about the AF. I use MF a lot, I don't really trust AF for getting things perfectly sharp but it's real nice convience having it. Just luck of the draw, go a lemon on AF. My recommendation is get the lens if you're thinking about it, it's worth it. If the SDM fails, it fails. Mine is an older lens, so it may have other issues too. I don't hear to many complaints about the newer lenses.

[woodywesty]

It is a great lens, the IQ wonderful, and the focal range is really great too. I have a Nikon buddy who has a similar Nikon lens and he can't get to the same level of IQ on his. Makes him crazy because he paid quite a bit more than I did. I really love it. I'm just bummed about the AF. I use MF a lot, I don't really trust AF for getting things perfectly sharp but it's real nice convience having it. Just luck of the draw, go a lemon on AF. My recommendation is get the lens if you're thinking about it, it's worth it. If the SDM fails, it fails. Mine is an older lens, so it may have other issues too. I don't hear to many complaints about the newer lenses.

I feel for ya... but I'd still call Pentax in Denver and see if there is anything they can do to fix a defective product. Especially since you've had it fixed twice already. I plan to call B&H and chat with them and see if they will give an opinion or if they know whether Pentax actually did redesign/fix the autofocus parts. I think that this lens is the best option for me at this point but I need to see if I can learn more about the problem being fixed.

[Andi Lo]

I suggest you really look at post #4 in this thread. Convert the lens to permanent screwdrive. I haven't attempted it (sweared off SDM years ago) but lots have done so succesfully.

Imho the sdm issue is unacceptable but Pentax community is so great, we actually made our own fix

Out of curiosity which lens is the Nikon one that your friend has? Is it the 16-85 or 17-55/2.8?

[david94903]

I've thought about doing the screw drive conversion, and may go that route. And you're right about the Pentax community being great. Having PF in my back pocket, as it were, has done a tremendous amount for me since I've joined. Including to sticking with Pentax (hear that Ricoh!?!) My Nikon friend has the 17-55mm F2.8, it's a nice lens but my 16-50mm beats it every time. And it doesn't matter if it's on my K20d, my K-5 or my K-01. It's just spectacular. Except the SDM issue. Which is sort of embarassing.

[aleonx3]

I've thought about doing the screw drive conversion, and may go that route. And you're right about the Pentax community being great. Having PF in my back pocket, as it were, has done a tremendous amount for me since I've joined. Including to sticking with Pentax (hear that Ricoh!?!) My Nikon friend has the 17-55mm F2.8, it's a nice lens but my 16-50mm beats it every time. And it doesn't matter if it's on my K20d, my K-5 or my K-01. It's just spectacular. Except the SDM issue. Which is sort of embarassing.

I am just curious about your SDM failure the second time; I have both DA* lenses replaced with the newer SDM motor. I have not had any problem since then, although I am still a bit worrisome that it may fail again. I do not use them as often since I like using primes. So far so good for me, but I can understand your frustration as well. When I am not using the lens, I store them upside-down standing up rather than lying horizontal (which I did before my DA* 50-135 failed) but not sure if it helps or not. Just a thought...

[snake]

Really unfortunate. I asked someone in another thread where their SDM also failed to see if they can get us the parts and somehow confirm if there are redesigned parts, as we've heard every year for four years now (look it up on DPR!). I'll wait and see.