Originally posted by AirSupply
I heard Pentaxpoke said that he cleaned his 50-135 by a fiber clooth and the lens's SDM was dead after that.
What!?!
The way you wrote that implies that I said that the act of cleaning the contacts killed the SDM.
I never said that.
Cleaning the contacts with a microfiber cloth will not damage the contacts. What I said is that after the lens exhibited SDM intermittency, I took the steps that people are fond to recommend: clean the contacts. It had no effect.
"Clean the contacts" is one of the most overused recommendations there is. All modern lenses have contacts for different functions. How often do you hear that people need to clean them to get their lens to work properly? Cleaning lens contacts is one of those urban myths that somehow got started as a fix to SDM. What most likely happened is that the act of dismounting and remounting the lens "woke up" the SDM, as does spinning the focus ring sometimes.
Please be more careful when attributing a recommendation to another person. If you want to quote me, fine. But please quote what I actually said, and in context.
In fact, I will do it for you. Here is the thread where I talk about cleaning the contacts:
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/81128-more-sup...-problems.html
And here is exactly what I said on the subject of contacts cleaning:
Originally posted by PentaxPoke Before I get the inevitable "did you clean the contacts" question...the answer is "yes." I cleaned the contacts with microfiber cloth, and they are so clean and shiny you can see yourself in them. It is not the contacts! Also, I take immaculate care of my lenses, storing them in their protective pouches in an air conditioned environment when not being used.
So where are you getting that I cleaned the contacts, and then the SDM was dead?