the shop replaced the lens for me. I took in some photos that clearly showed the problem.
The new lens is much better, although I think there may still be an issue with mis-focus from time to time. I haven't yet had a chance to try it out properly. I am going to Wales for a week soon, so will give it a really good test then.
Could you explain what you mean by EXIF data?
I always shoot in RAW mode. The EXIF data is retained with each image file & contains data such as aperture, shutter speed, time, date, subject distance, lens used & focal length at time of shot, plus much more info. I believe this info is also included when shooting in JPG output mode.
Most image editing/conversion programs have the option of viewing or extracting the EXIF data.
I hope this answers your question.