| Author | Message | ||
     Glenn Tinkerer Username: Glenn Post Number: 794 Registered: 07-2006 Rating: N/A |
Marco, I had a feeling that you had a nFD (serrated) lens cap on a breech lock lens. Now Mark (Agno3) is quite correct in stating that the nFD cap will fit a breech lock lens and the cap can only be put into the mount in one position due to the key effect of the larger lug - just as in the nFD mount, but fitting a worn nFD cap to a breech lens always runs the risk of the combination jamming - the breech ring does not always rotate when the cap is pushed in, depends on the lube used on threads of alloy ring ( I like a fairly heavy grease on these threads so ring does not self rotate on my bL lenses). You say that you can see part of one lug - correct? Is this the lug opposite the triangular position marker on the rear of the cap (this lug has a raised stop on its lefthand end, viewed from rear of lens and is longer than the other two lugs) and if so, can you see the end of the silver lens locating pin positioned in the lug's location slot? The locating pin can be hidden for two reasons, the breech ring has rotated enough to cover the pin or the cap has become misaligned and pin is under the lug. I am trying to ascertain the actual radial positioning of the cap in the rear mount - Is it correctly positioned, but due to sloppy fit/wear the cap has rotated clockwise (viewed from rear) in the mount, thus becoming jammed under the breech ring without releasing the breech ring lock that stops the ring from being turned. In this instance the breech ring will obviously appear to be jammed, only by forcing the cap to rotate anticlockwise will allow separation. The aforesaid raise stop on the end of the longer lug can also get jammed under the breech ring, but in this case none of that lug will be visible - well only about 1/16" peeping out from under the ring so to speak. This really requires a well worn cap and a very ham fisted operator to achieve - in this instance the ring could be locked or unlocked. Clearly my comments on turning the breech ring in my first post are only valid if the ring stop is released. As this is impossible to actually see, you should always try turning the cap anticlockwise first unless the lens locating pin is clearly visible in the lug's slot. As you have both BL and nFD lenses and correct caps I suggest you examine both closely and I think you will soon see the areas that can cause problems. Knowing these I think you will find the solution much easier than writing about it! |