|
Forum: Lens Clubs
09-23-2013, 10:03 PM
|
| |
| |
|
Forum: Pentax SLR Lens Discussion
01-27-2011, 02:32 AM
|
| |
There have been so many posts about the problems with SDM in this model, and only a recent DIY fix, that I thought I'd add to the discussion, and let you know that the fix worked for mine.
Needless to say, I'm a bit pleased about it.
Nearly 12 months ago, the lens (attached to my K20D, where it had become the default optic) took a short tumble - about 150mm - into soft, sandy soil. Good sealing all round meant that a quick brush and blow or two later cleared off any grit-entry potential, but the SDM began to falter shortly thereafter, and eventually stopped altogether. Since then, it's had a few days of MF work on the K20D, but mostly stayed attached to the *istD (where the screw-drive functioned, at least) or in its pouch.
Discouraged by what I read in these forums, I left it there until the past few days, when I read of the Chinese Pentaxian who had dismantled the back of his 16-50 and manually worked the SDM rotor until it came back to life. I've attempted to find the post again, but it must be buried in one of the many threads about the SDM problem. It might not even have been on PentaxForums.
Regardless of all that, the technique has worked. What remains is to pin down precisely why the problem occurs (I've read some pretty unlikely theories about it, all asserted boldly, as they are) and whether we can be confident that there's now a standard, simple and inexpensive fix available.
It took me all of half an hour, including dismantling and reassembling, so that should be a reasonable benchmark for a professional bit of work, for which anyone worth their salt as a camera technician would probably charge a minimum of one hour's labour. The usual precautions about preparation, including cleanliness and proper lighting apply, of course.
I have to say that I am trained in Mechanical and Electronic Engineering, but I'm an Engineer, not a Technician. I'm more used to working on larger-scale devices (like motor-car insides, and then as a hobby), so I claim no special expertise. Until I saw the photos of the dismantled 16-50, I didn't really have the confidence to tackle this blind.
But it works! Maybe it'll need doing again in the future, but at least the spell is now broken, and a good independent Pentax technician should be able to pioneer a standard procedure and, if it needs it, a permanent fix.
Good luck with yours! (maybe a steady hand and your macro lighting setup might be better than luck)
Cheers
Rob
|
