[Jewelltrail]

This is really a sad and eye opening thread for me. It is hard for me to believe this many people have this problem with such a fine lens as the 50-135. Pentax had better do something, quick, or it is going to hurt them.

For example I am currently sitting on the fence of my ultra-wide lens purchase. One of the things which makes the third party lenses more appealing is their, in comparison to Pentax, extremely generous warranties. A thread like this, although I understand the 50-135 problem has nothing directly to do with performance of other Pentax AF lenses, might just be the deal-breaker in my next lens purchase.

I can't imagine a much more disheartening experience than saving for the 50-135, and then having to deal with this--even an extended warranty does not fully ease the pain of losing the lens while it is being repaired. So sorry for everyone afflicted here.

[jeffrey r]

You have every right to be concerned Jewelltrail. By now, the problems with the 50-135 focus mechanism is clearly not an isolated incident. In my case, I have not had any failures yet (knocks on wood), but compared to my DA limited lenses, and my Tamron zoom lenses for example (17-50 and 28-75), my 50-135 hunts for focus quite a bit more (especially in lower light) and is slower to lock focus. Yes, the SDM is very quiet, but I would trade that for the faster more reliable focus of my other lenses.

Since I bought my 50-135 used, I am sure I would need to come out of pocket for a repair if necessary, so hopefully I don't get to that point. These problems with the 50-135 are a shame, because it really is a stellar lens otherwise.

[Mik]

Anyone know if the HSM focusing on the Sigma APO 50-150mm F2.8 II EX DC HSM has similar problems on a Pentax? I was considering a DA* 50-135mm up until Pentax doubled the price in Canada and reading about all the problems people are having with SDM.

[Canada_Rockies]

Every time I mounted the lens, I would have to dismount, remount, fiddle and faddle as in the posts above. PITA.

In another thread, I was having trouble getting my M 400/5.6 to work properly with the AF 1.7X converter. It was suggested that I might have grease or crud of some description on the metal base of the 400 lens, and the converter needed to have a clean contact to short out the contacts to make it work. I cleaned the base of the lens thoroughly (not something I would normally do!) using microfibre cloth and alcohol from my eyeglass cleaning kit. Voila! problem solved. Yay!

Tonight I put the 50-135 on the camera for the first time in a couple of weeks and it worked first try. Perfectly. Quickly. Accurately.

I think I have a major coincidence here. I'm going to clean all my lens' bases. I'll keep you all posted if it acts up again. It kind of makes a warped bit of sense. If the contacts are dirty, no juice, and it is a heavy lens to turn.

[asdf]

This is really a sad and eye opening thread for me. It is hard for me to believe this many people have this problem with such a fine lens as the 50-135. Pentax had better do something, quick, or it is going to hurt them.

For example I am currently sitting on the fence of my ultra-wide lens purchase. One of the things which makes the third party lenses more appealing is their, in comparison to Pentax, extremely generous warranties. A thread like this, although I understand the 50-135 problem has nothing directly to do with performance of other Pentax AF lenses, might just be the deal-breaker in my next lens purchase.

I can't imagine a much more disheartening experience than saving for the 50-135, and then having to deal with this--even an extended warranty does not fully ease the pain of losing the lens while it is being repaired. So sorry for everyone afflicted here.

Hoya board of directors should all commit seppuku. My eyes are filled with tears and my heart with the deepest despair and haunting horror, as I kneel here beating my chest and tearing my clothes in anguish. I only wish the families of those affected eventual solace.

[Lloydy]

Every time I mounted the lens, I would have to dismount, remount, fiddle and faddle as in the posts above. PITA.

In another thread, I was having trouble getting my M 400/5.6 to work properly with the AF 1.7X converter. It was suggested that I might have grease or crud of some description on the metal base of the 400 lens, and the converter needed to have a clean contact to short out the contacts to make it work. I cleaned the base of the lens thoroughly (not something I would normally do!) using microfibre cloth and alcohol from my eyeglass cleaning kit. Voila! problem solved. Yay!

Tonight I put the 50-135 on the camera for the first time in a couple of weeks and it worked first try. Perfectly. Quickly. Accurately.

I think I have a major coincidence here. I'm going to clean all my lens' bases. I'll keep you all posted if it acts up again. It kind of makes a warped bit of sense. If the contacts are dirty, no juice, and it is a heavy lens to turn.

I've used one of these fiberglass abrasive pens for contact cleaning, mainly because that's one of the things it's designed to do.

| PCB Prototyping & ESD Handling | PCBs or Prototyping Systems | PCB Tooling | Hand Tools

I know some people will be shocked to hear of the use of an abrasive on a lens, but it really is so fine that when used gently there is no scratching.

An added bonus is, it's dry and accurate.

The link is to R.S. Components which is a U.K. Company, but any decent electronics supplier should carry a similar product.

[panoguy]

I have a relatively new DA*50-135 (B&H got it as part of a shipment in March), and what I've noticed is that the SDM focusing is rather slow and pokey compared to the version I tried in a local store (which was older). No difference after the 1.01-1.0.3 firmware update in my K20D, either. After a month of moderate use it hasn't failed to focus, but it's basically glacial compared to even a screw-drive equivalent.

Of course, the last SDM-type lens I had was the Canon 70-200 f/4 L, which was a comparative speed demon, even when the AF on the body was hunting. Plus, I rarely used it, and once after nearly 2 years of sitting (the rubber grips had started to go white!) the motors would still zip right up, nice and tight.

I wasn't terribly impressed with the Pentax 17-70 SDM and got the Sigma (while louder, it is faster and quite crisp), and I really wonder why it seems I'm "expecting too much" from this now $1700 CDN lens! (If I had paid that price, I'd expect it to at least equal an "L series" in performance.)

Frankly, I think Hoya/ Pentax should hold these DA* lenses to the same QA and standards that the Limiteds go through. These are modern "pro level" lenses in spec and cost, and should act like it *and* stay that way.

1. The Sigma (I'm guessing you're talking about Sigma 17-70) is slower where it actually matters: at the long end.

Uh... yeeeaaah... I guess focus speed doesn't mean much. Maybe it was a bum copy at the store, but the DA17-70 I tried was basically "quieter" but fell short of the Sigma 17-70 in everything else (sharpness, bokeh, focus speed, close-focus distance, build quality). But, hey, that's my experience and opinion... YMMV.

2. DA 17-70 sells for $750 CAD at Aden Camera. (Were you referring to a different lens?)

Read the post and thread title again. We're talking about the 50-135, and I brought up the 17-70 as another example where Pentax is charging too much for SDM and their name. The Sigma is simply a great alternative to the DA 17-70 (and I paid $550 CAD at Henry's of all places!).

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Last edited by panoguy; 05-03-2009 at 11:21 AM.

[PentaxPoke]

The other odd thing my 50-135 started doing, is that the quick-shift would not always work. I would spin the ring, but the lens would not change focus. It is as if the SDM motors were frozen, and holding up the focus, but not the outer ring. Once I could get the motors moving again, then the quick focus would work.

I repeat again, it is NOT a dirty contact problem.

[Canada_Rockies]

The other odd thing my 50-135 started doing, is that the quick-shift would not always work. I would spin the ring, but the lens would not change focus. It is as if the SDM motors were frozen, and holding up the focus, but not the outer ring. Once I could get the motors moving again, then the quick focus would work.

I repeat again, it is NOT a dirty contact problem.

That sounds very much like a problem to have repaired. I feel for you. The lens is so great when it works properly, I cannot imagine being without mine for any length of time.

[asdf]

Uh... yeeeaaah... I guess focus speed doesn't mean much.

I was referring to the aperture. Sigma is slower at the long end (f/4.5 vs. f/4 for the Pentax).

About your mileage comment: from what I've seen so far, the camera operator is what seems to affect the mileage most.

[PentaxPoke]

That sounds very much like a problem to have repaired. I feel for you. The lens is so great when it works properly, I cannot imagine being without mine for any length of time.

Thanks Albert,

What makes it worse, is that I really was counting on using that lens for my daughters recital that is coming up at the end of May. Her yearly recitals are one of the main reasons I bought the lens in the first place. The problem is that my warranty runs out at the same time! I went ahead and boxed up the lens and sent it off to Pentax. Depending on where I have to sit, maybe I can use my DA 70 Limited instead.

I am batting 1000 on DA* lenses...every one I have owned has had a manufacturing defect of one type or another.

[Canada_Rockies]

Thanks Albert,

What makes it worse, is that I really was counting on using that lens for my daughters recital that is coming up at the end of May. Her yearly recitals are one of the main reasons I bought the lens in the first place. The problem is that my warranty runs out at the same time! I went ahead and boxed up the lens and sent it off to Pentax. Depending on where I have to sit, maybe I can use my DA 70 Limited instead.

I am batting 1000 on DA* lenses...every one I have owned has had a manufacturing defect of one type or another.

That is the excrements (substitute appropriate four letters + s word as desired). Here I am with three camera bodies and eight lenses and they mostly work as they should. The FA 28-30 power zoom switch fell off, of course, and the 50-135 has acted up in the past, but generally speaking I've been on the lucky side of the street.

Let us know what Mr. Pentax has to say about it.

[xxxxx]

Scary. My copy's working fine, it's also near end of 1 year US warranty. Supposedly my credit card should extend it another year. We'll see. :S

[frogger]

14 months old (bought it used) and mine is starting to act up. First time it after turning it on takes about 15 seconds to wake up and eventually focus. After that it works ok. Leave it idle for 10 minutes and it needs the long focus time again.

[NeverSatisfied]

I was referring to the aperture. Sigma is slower at the long end (f/4.5 vs. f/4 for the Pentax).

About your mileage comment: from what I've seen so far, the camera operator is what seems to affect the mileage most.

Obviously based on your flippant remarks thoughout the thread, YOU haven't been affected by any of these problems. Luck of the draw! So according to your theory then if we all became better photographers like you, Pentax's quality control problem would just simply disappear...