What does a Screwdrive Converted Pentax DA* 50-135mm F2.8 lens sound like?

Tom__Brown wrote:

brandrx wrote:

OnTheWeb wrote:

It was captured with decent quality microphones so hopefully this gives you some idea what to expect after you convert your lens to screwdrive once your SDM fails, which is inevitable.

I completely disagree with this part of your statement, " ...once your SDM fails, which is inevitable."

If you had written, "...if your SDM fails.", and left off, "...which is inevitable." then your post makes some sort of sense. Otherwise it just seems to me to be Pentax bashing.

Just my opinion.

Hi Ron.

Thanks for suffixing your post with "Just my opinion." That's more than fair.

The "which is inevitable" is open to debate and certainly not proven. It seems like hyperbole to me. That is something this forum has plenty of.

Time will tell how many of these SDM systems are still functioning 10 years into their lives but I fail to see why it is necessary to "spin" the forum narrative in favor of Pentax.

There are a few people who will counter any reports of SDM failures with something like, "Well, I have an SDM lens that has not failed so this is a perception problem, not a real problem." Do you jump on those people?

My hunch is that there will be examples of SDM lenses that last more than a decade without failure. The 50-135 seems to have lower reliability so fewer working examples of that lens may make their 10th anniversary without repair, we won't know. That could be due to the focal length lending itself to being used less frequently or it could be a design issue. Either way, there are plenty of reports of failures and you don't have to go beyond this group to find plenty of those reports.

There is a good chance the 16-50 and 50-135 have more failures because they sell in larger numbers than the other lens, They've also been around longer.

There will be more 10 year old 50-135 and 16-50 still running purely because more are made and sold, it makes no odd unless your look at number of failures Vs lens sold.

As Pentax do not release these figures you can only get an approximation of failure rates by educated guessing.

This man had a failed lens. The SDM issue is real. Pentaxians need to deal with it.

Is it,? again show me your figure that prove SDM 'issue is real.?

Plenty have SDM failure me included that doesn’t mean that SDM issue is real unless you can show figures that show SDM is more failure prone than anyother ultrasonic drive system.

This you will fail to-do as sticktion is an issue of piezo drives not SDM unduly

I'm happy to believe you and join a crusade to sink Pentax but not on the say so of web zealots with no facts to back them up.

Web forums are a nest of misinformation due to human nature.

Those with fully functional SDM are taking picture not posting.

Those with failed SDM seek out somewhere to vent.

Ron

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Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'
'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx

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-- Tom