| Author | Message | ||
     Arfd Tinkerer Username: Arfd Post Number: 29 Registered: 01-2013 Rating: N/A |
Firstly, I have not worked on that zoom lens, but are you absolutely certain the front element needs removing? Usually in telephoto zooms the front focusing group comprises 3 elements, the 3rd group being held by a retainer inside the barrel. To access the whole front tube must be unscrewed, this is sometimes possible by looking for a focus stop screw under the grip leatherette. When unscrewing the front tube make a note where it detaches from the helicoid, it will make reassembly much easier. A trick I have found useful on stubborn retainers is to apply a few very small drops of WD-40 to the edge of the ring, let it soak in for 30 minutes then apply some drops of acetone. As well as loosening any glue the acetone seems to 'push' the WD-40 into the threads. Of course, this treatment has the potential to produce oily smears on glass surfaces that are difficult or 'impossible' to reach! So use with caution. |