Originally posted by jonhock First, I don't even know if the tape would work, and secondly, if a piece of electrical tape did work I would be sure to change it whenever I used an SDM lens. I have Sigmas with HSM motors but I've never had a problem with them. As stated above, my copy of the SMC Pentax-DA* 50-135mm F2.8 ED [IF] SDM is on the way. I'll try it and see if it works.
There have been many many many people who have already tried this and found it does not work. It should not work since the SDM contacts (as stated in my reply above) do not have anything except power on them. They have nothing to do with the lens telling the camera it is SDM capable. People have had the SDM tabs on lenses and cameras come off in accidental impact only to find the camera and lens still want to use SDM.
Feel free to test but this has been well established already as not relevant.