[Waheed_Sadaf]

I have been recommended the DA* 50-135mm from someone and have looked into it and it's what I have been looking for, nice sharp optics.
However, I have read some reports of its SDM focus issues/failure. Not sure how much truth there is to it but want to ask that:

Is the SDM failures too much exaggerated or there is issues with it and its down to maybe luck as to whether i get good copy or not?

Has the SDM failure been addressed and new lenses made are safe to buy?

Should i be worried/concerned about this issue when considering any SDM lens?

Any precautions you take to avoid such failure?

This would help me decide. As there are two paths am looking into now, one is this long focal length scale i.e. DA* 50-135mm and the other is wide angle i.e. DA 12-24mm or Sigma 10-20mm. its going to be one or the other

Thanks

EDIT: I dont want to be missing out on the prices these lenses are going at the moment or is there any reason/link to the SDM issue. Am too confused!

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Last edited by Waheed_Sadaf; 11-23-2009 at 08:26 AM.

[innershell]

I'm interested in this lens too and the answers to the questions asked above. Subscribed!

[sebberry]

I am also interested in picking up the *50-135, but I don't want problems with the SDM system, especially when the warranty is a pathetic two years.

Mods: Perhaps we should have a sub-forum dedicated to 'Pentax SDM". Maybe that would get the attention of the Pentax people who read these forums.

On one hand they don't want to admit there is a problem because that would open up a can of worms for all the broken lenses people had to pay to have repaired, but on the other the lost business due to people wanting to stay away from SDM lenses (ya know, those expensive DA* ones..) is mounting.

[PentaxPoke]

All copies of my SDM lenses (3x 16-15 and 2x 50-135) have had QC problems. Personally, I am staying away from all SDM lenses. There are some here that swear by them. Many of us however, swear at them.

My recommendation to people is to stay away from SDM lenses. IMO they were rolled out as a "me too" product, and have a much higher failure rate than any other Pentax lens product. I have been buying Pentax glass since the early 80's and have NEVER had a problem with any of them...until the DA* line.

I agree berry that Pentax can never admit there is a systematic problem with the SDM line of lenses. To do so would open a returns floodgate that would cost millions.

[jpzk]

I totally agree with this, sedberry.
I recently contacted Pentax Canada regarding SDM failures on at least two lens models,and all they could answer was that :We ship defective lenses to Japan"! Hilarious?!
I also contacted Ned Bunnell (or replied to one of his thread on Photo.net) regarding the hyped-up concerns with the K7 ... no reply.
I am for a sub-forum dedicated to "SDM" lenses, whatever focal lengths they are.
JP

[xGene]

Just pasting my recent reply to the "SDM Problems" thread started by PentaxPoke:

PentaxPoke;

I experienced the EXACT same symptoms as you on my 50-135: it would take about 30-40 seconds to wake-up then it would work OK until I put it away and then it would act the same THE NEXT DAY! I have a K10, 2-K20's and now a K7 and it would exhibit the same problem on all bodies. Cleaned the contacts, played with the focus and zoom rings to no avail. It was like there was a timer in the damn thing!
Went to Pentax Canada here in Mississauga (I work on the next corner), they would of course deny any knowledge of any problems with SDM's, on any lenses! It was quite funny (not really, in retrospect) while I was there arguing with the Pentax rep., when the representative of a reputable distributor here in Toronto walked-in with not one, but two (!) 50-135's with failed SDM's!!!!
They finally took the lens back and gave me another one, one week later, which works OK so far, although the serial number is older that the one I "surrendered". I assume it's a refurb.

To Little Laker's comment: I respectfully disagree. I use this lens or a very regular basis, at least twice a week, and this should NOT be happening. We are not talking about storing the lense for six months to a year here.

Gene

[netuser]

I have DA*300 but want other sdm lenses and WILL NOT BUY until there is a solution for this problem.

[sebberry]

Here's an idea:

Pentax develops a new SDM system and markets it as "SDM II". The primary *business* reason for the revised system would be to eliminate the problem component of the current SDM system causing the filures. They would also modify the motor so that it would focus a bit faster.

It would then be *marketed* as a faster system. Pentax wouldn't have to admit fault to a shoddy first-gen SDM system, and future SDM buyers could have more confidence in the system. New SDM II systems should come with a 5 year warranty for increased consumer confidence and the warranty on the old SDM system should be extended to 5 years on the SDM system only.

I would hazard a guess that many Pentax shooters using DA* lenses are aware of SDM problems. This isn't something Pentax really needs to keep quiet about and it could be a big oppertunity to market an improved SDM system and sell more DA* lenses.

[xGene]

There may never be a solution to this problem. It is not in Pentax' "culture" to admit to a quality and/or design flaw. On the other hand, I would assume (?) that Pentax addressed the issue on current production units.

Gene

[sebberry]

There may never be a solution to this problem. It is not in Pentax' "culture" to admit to a quality and/or design flaw. On the other hand, I would assume (?) that Pentax addressed the issue on current production units.

Gene

The problem with making that assumption is that for the people who are willing to invest $1,000-$2000 in a DA* lens want to know with a reasonable degree of certainty that the problem has been resolved.

I have been on the fence about buying a 50-135 for about a month now. The fact that they are on sale at a local retailer doesn't help. But not knowing if my $1,000 lens was made from the crap parts is keeping me from pulling the trigger.

To do nothing is costing Pentax, and potentially swaying some customers to Canon or Nikon's USM/SWM systems.

[Talisker]

Well, I'm sorry about everyones problems, honestly, as these things aren't cheap, but I'm one who swears by mine The 50-135 is superb optically - mine went down to the antarctic last year and over to Greenland this year - gets cold, wet, splashed with seawater and still comes back for more. The 16-50 I bought this year is fine as well so far.

As far as being a 'me to' product they're damned if they don't and damned if they do - before the SDM lenses were launched the complaints here were that Pentax needed to move on from screw-drive lenses. Of course they will have a higher failure rate than earlier lenses - there is more to fail once you start sticking motors in lenses. What was there to fail in an SMC-M lens as long as it was screwed together properly and you didn't drop it? I'm sure more motorised Canikon lenses fail now than twenty years ago...

[sebberry]

That's why I would like to know what component of the SDM system is failing. Is it due simply to it being a more complicated piece of equipment or is something in there cheaply made and breaks because of a design flaw/poor quality material.

Most of the SDM failures I am reading about here aren't because of abuse or misuse. They're simply dying unexpectedly.

[Waheed_Sadaf]

Well if I am to buy a lens that cost too much then surely I expect to keep it for some time without problem as many will say this too that SLR body wouldnt matter that much but its how good glass you use and how you use it that make excellent result.

By the way, is there similar issue with sigma HSM?

[bymy141]

KNOCK KNOCK!!

I haven't got a DA*50-135mm, but I do have a DA*16-50mm (an early 2008 copy) and a DA*60-250mm (last august purchase).
The 16-50 has got over 20,000 and the 60-250 has got over 4,000 images taken without any problems or SDM failures.

Both lenses have been used in harsh conditions (heath, cold, rain, frost), I do not use special equipment bags, instead I'm treating them somewhat careless.
Dust, losts of dust, moisture, rain, its all been around them.

Based upon my experience, these SDM lenses are GREAT stuff!

Of course you will hear the few with problems load and clear, and of course you will not hear all the thousands of happy users to compensate these stories.

I believe the money spend on my SDM lenses was worth every penny!....
(See my avatar [K-7 + DA*16-50mm])

- Bert

[sebberry]

By the way, is there similar issue with sigma HSM?

Probably even worse, knowing Sigma's quality control.