Originally posted by martin s How frequently has this lens been returned for calibration?? My lens seem to lack sharpness, and I was wondering if this is a common problem??
I seem to remember some QC problems.
Has Pentax been cooperative for problems like this??
Also, have the returned lenses actually been sharper after the calibration??
Please advise.
Martin
Martin,
There have been
numerous threads on this subject.
You might want to search the forum for them, before reacting some more.
There is even a thread collecting serial numbers of good and bad 16-50mm lenses.
You might want to compare your lens sn with there.
Most issues seem to be a combination of the camera and the lens.
People do report back focus issues somewhat more than front focus I believe.
Most of these issues seem to be camera problems, to be corrected by Pentax. Send the camera in for tuning.
Also people have lenses with lack of corner sharpness.
If this is what you experience, return the lens for a new copy.
Since the f2.8 DOF is very shallow, there has been a lot of discussion how to properly test this.
I advise you to have a look at these discussions as well, before returning your lens.
Most of the problems seem to stem from the earlier batches produced, while not all lenses were having problems.
My copy is fine, my K10D is fine, while the guy with the lens with my serial number + 1 has problems.
It also seems that Pentax finally got most QA problems under control now and we have seen little issues reported lately from the latest batches produced.
Success,
- Bert