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Author Message   Contaxfan Tinkerer Username: Contaxfan Post Number: 1 Registered: 07-2010 Rating: N/A Votes: 0 Posted on Thursday, July 22, 2010 - 05:46 am:    For this kind of zooms which using the front group of optics for focusing you need not to remove the front elements. Here is the procedure for 30A 1. Remove the rubber grip on focusing ring 2. Zoom the lens to 200mm and infinity to set the reference point 3. Using marker to mark the position of all rings and the front portion of the lens related to the marking line (you can draw a line from end to end along the lens). 4. Remove all tapes which are used to stick two rings together on focusing ring. Please make sure you do use the marker to mark the position of these rings. 5. you will find two screws which are used to guide the focusing group (aka the front portion of the lens). 6. remove these two screws 7. Place you lens in vertical position 8. turn the focusing group in anticlockwise "SLOWLY". It will separate with lens body within a turn. And don't put this portion out when you find the "point of separation". 9. Using marker to mark the point where the separation point is. Later you need to put back the lens at the same position. 10. Then you can separate the front portion of the lens!!! 11. after cleaning, just turn the front group back to the lens body at the point where it comes out. 12. Try using 95% alcohol to clean the lens surface. Then using water steam to clean the residues. You also can use peroxide mixed with wetting agent ammonia to kill the fungus on the lens first then by alcohol then by steam. In my opinion it is no way to remove the fungus spores from all lens surfaces. The reason is that our air is full of spores. If someone told you he can remove all the spore from the lens, he is telling lie. Once the lens came out from the clean room in factory the fungus spores will get into the lens when you use it. To kill the remain fungus in the lens you can use the UV lamp (UVa) or simply under the sun. You also can kill the fungus by fungicide but it is not easy to get them in open market. Most of them are sold to libraries and labs. The best way to prevent the fungus infection is to keep the lens dry and use them regularly.