Photoclubalpha

I can't speak for others, but in my case there wasn't much for me to respond to in your posts. I don't have a Sony 300mm f2.8 so that wasn't of much interest. I don't live in the UK so the local repair place you found or that David recommended were of no interest. I have already had a poor experience with Sony service in the U.S. so what can be said about your experience other than I am not surprised. I suspect many people didn't reply since about all they could have said was: Good luck!

Anyway, good luck!

I have the lens back and it's now perfect again.

I can highly recommend the repairers and here is a link to their website:

http://www.1staidrepairs.co.uk/

A question for David maybe.

They gave me back the damaged front element (it's very much thicker than I imagined) and it's obvious that it's coated on both faces. If I had gone the 'filter way' would you expect a filter to be coated both sides?

Just being inquisitive.

MickH

Glad you got it fixed Mick, and useful to know about the repairer.

Mick - thanks for the info. Yes, current filters of the right quality are multicoated on both sides and the nanocoatings on the front are very hard and resist water, oil, dirt. It is unlikely that the lens would benefit from a thick filter, but it would benefit from extreme planarity and parallelism of surfaces. That is easier to do working with a relatively thick, stable optical blank which is not flexible when being plane polished.

Long lenses like the 300mm aree extremely susceptible to loss of resolution overall, if a poor quality filter is ever used in front of them. Wide-angles show patches of resolution loss, and many of the current pols and UVs from China have visible patches of poor plane-parallelism (they are not perfect optical flats).

This is the difference between Hoya Pro1, Marumi, and Kenko Pro - all brands from the Hoya works, but in order of optical quality. Put a Kenko filter on a long zoom like the 70-400mm and you'll think the lens is poor. Even the top line Hoya is not always perfect. That's why some other brands like B+W, Heliopan, Rodenstock have been more expensive. But Hoya has caught up.

The front protector of the 300mm must be absolutely the best glass, as you can't remove it to use the lens 'pure'. So the genuine part replaced at reasonable cost is a great outcome.

David