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02-09-2011, 08:19 AM   #16
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QuoteOriginally posted by Tom S. Quote
Could it be because the 16-50 lets more light in enabling quicker focus? Unless you manually stop both lenses to the same F setting (and keep it there during focusing), the 16-50 will always get more light to the sensor.
No, it is not.
You can see this on this old K-7 SDM speed test I did with both the 60-250mm and the 16-50mm.


I guess the lens group that the 16-50mm needs to be changed is much smaller / lighter than the 16-50mm, so the same motor can use a faster transmission.

Cheers, Bert

02-09-2011, 08:25 AM   #17
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QuoteQuote:
The truth is there is no new or better generation of SDM.
My new DA 18-135 is labelled DC not SDM. So I'm guessing that is the new SDM, so if it says SDM, it is. Apparently DC is the "new better" SDM, but I bet they sell off old stock of all their SDM lenses before they retool their lines for the newer version.. and of course, it's the newer version of a lens from the same engineers that brought you SDM, so is it really going to be better? Or did they just change a few mounting screws and the name?
02-09-2011, 08:36 AM   #18
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I like the 60-250 so much that I ordered one too. Arriving tomorrow.
02-09-2011, 10:48 AM   #19
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QuoteOriginally posted by normhead Quote
My new DA 18-135 is labelled DC not SDM. So I'm guessing that is the new SDM, so if it says SDM, it is. Apparently DC is the "new better" SDM, but I bet they sell off old stock of all their SDM lenses before they retool their lines for the newer version.. and of course, it's the newer version of a lens from the same engineers that brought you SDM, so is it really going to be better? Or did they just change a few mounting screws and the name?
I don't think that's right at all. The DC is a completely new motor designed for the more 'budget' priced lenses. SDM has been retained in the most expensive DA* lenses.

02-09-2011, 11:18 AM   #20
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QuoteOriginally posted by GaryH Quote
I like the 60-250 so much that I ordered one too. Arriving tomorrow.
When you do get it, please place some results in:
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/114743-da*-60-...at-can-do.html

Thanks, Bert
02-09-2011, 07:13 PM   #21
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QuoteOriginally posted by GaryH Quote
I like the 60-250 so much that I ordered one too. Arriving tomorrow.
You need to get an extended warranty with that! Consider it a part of the price of the lens
02-09-2011, 07:31 PM   #22
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QuoteOriginally posted by JHD Quote
You need to get an extended warranty with that! Consider it a part of the price of the lens
Why buy an extended warranty? I bought the lens with still 9 months warranty left.
I have 4 sdm lenses with no issues. If i would have spent $$ on each for an extended warranty, I could have bought another lens. I buy products that I have faith in and I would rather not support 2nd party insurance companies. Others might have differing views, but at this point, I feel that if I do have a failure, i could afford to get it repaired on my own with the money i have not spent on extended warranties. BTW-I do not buy extended warranties for cars or anything else.
02-09-2011, 07:33 PM   #23
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QuoteOriginally posted by bymy141 Quote
When you do get it, please place some results in:
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/114743-da*-60-...at-can-do.html

Thanks, Bert
I sure will
If the SDM lasts long enough to get any pictures....Lol!

02-09-2011, 07:34 PM   #24
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QuoteOriginally posted by JHD Quote
You need to get an extended warranty with that! Consider it a part of the price of the lens
QuoteOriginally posted by GaryH Quote
Why buy an extended warranty? I bought the lens with still 9 months warranty left.
I have 4 sdm lenses with no issues. If i would have spent $$ on each for an extended warranty, I could have bought another lens. I buy products that I have faith in and I would rather not support 2nd party insurance companies. Others might have differing views, but at this point, I feel that if I do have a failure, i could afford to get it repaired on my own with the money i have not spent on extended warranties. BTW-I do not buy extended warranties for cars or anything else.
I've tried to explain this concept to JHD on several occasions (like here) but he's too distracted by his hatred of all things SDM (and maybe all things Pentax) to listen.

Obviously the concept of self-insuring against a possible (not probable) failure is a concept he'll just never grasp (or acknowledge).
02-09-2011, 07:38 PM   #25
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QuoteOriginally posted by dgaies Quote
I've tried to explain this concept to JHD on several occasions but he is too distracted by his hatred of all things SDM (and maybe all things Pentax) to listen.

Obviously the concept of self-insuring against a possible (not probable) failure is a concept he'll just never grasp (or acknowledge).
If I were so paranoid about a system, I believe I would pack up my toys and go play elsewhere.
C/N have forums of disgruntled people where he would fit in just fine. And as a bonus, there is a larger audience for him to amuse.
02-10-2011, 01:59 AM   #26
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With $7000 invested in Pentax, I dare say not everything Pentax makes is a photographic god send and that it is prudent to pick and choose wisely. This of course is where blind fanboyism parts company with the sage.
02-10-2011, 04:27 AM   #27
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QuoteOriginally posted by JHD Quote
With $7000 invested in Pentax, I dare say not everything Pentax makes is a photographic god send and that it is prudent to pick and choose wisely. This of course is where blind fanboyism parts company with the sage.
I haven't seen any "blind fanboyism" on this page. Not sure what you are reading.
02-10-2011, 05:32 AM   #28
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I wasn't calling out anyone specifically. However it seems like there is a tendency of insecurity among many folks who chose this brand and they feel it is their solemn duty to defend everything and anything Pentax - no matter what.
02-10-2011, 06:05 AM   #29
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It appears that the insecurities shown are by folks who are paranoid about Pentax products failing and want to try to muddy up any thread that invites discussion about a lens or camera with dire warnings that what ever they do, they are eventually doomed to the failure of their equipment and that they are somehow weak minded if they do not share the same paranoia.
I have had bad experiences with certain car makes and would never buy one again. However , I am not wasting my time on internet forums warning the fanboys of that car make that they are doomed. I am here for constructive advice about a hobby and that is all. My equipment choices are mine to own and I along with everyone else here are fully aware that there have been SDM issues with some users. Still, the choice to buy a certain camera or lens is up to the individual. Perhaps those who are passionate about their issues with SDM should create their own forum for those discussions. Maybe we should start a SDM haters thread and let those folks have at it.
02-10-2011, 07:03 AM   #30
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QuoteOriginally posted by JHD Quote
I wasn't calling out anyone specifically. However it seems like there is a tendency of insecurity among many folks who chose this brand and they feel it is their solemn duty to defend everything and anything Pentax - no matter what.
And at the same time it often appears that there are certain people who go out of their way to bash Pentax and take a shot at the brand every chance they get. Bottom line is neither behavior (either blindly supporting or constantly bashing) is very useful in terms of having a useful discussion.

I personally don't feel I blindly defend Pentax, nor do I feel any obligation to. I have a lot of Pentax gear, by my own choice. I have on many occasions stated that there are several things Pentax could have done to mitigate the "SDM issue", including extending warranties and/or allowing screw drive to be used on dual drive lenses. However, even if those things don't happen (which I am not going to hold my breath on), it doesn't mean owning and using DA*/SDM lenses is a bad choice. That is the position I have tried to "defend", however in no way are the opinions and thoughts I post "blind fanboyism". I believe the content of what I post (relating to SDM lenses) speaks to that.
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