I think I need to make the collar from something harder, aluminium is a bit soft.. but it may work. We can try it over next week.. if you have the courage :-)
One thing I just realised - the collar with the grooves will need to taller than the screw-head, to fully reach all the filter threads in the lens. There is only about 5mm or so of space in front of the lens. I hope that makes sense...
One thing I just realised - the collar with the grooves will need to taller than the screw-head, to fully reach all the filter threads in the lens. There is only about 5mm or so of space in front of the lens. I hope that makes sense...
Cheers,
V
It does, very much so.
Maybe I will have to trim the screw head that holds the roller/collar a bit to prevent a damage to glass.
Can you make a rough cross-section drawing (or better image) of the front glass assembly with some measurements?
Attached are some images I just took. If you need any more, or I've missed something then don't hesitate to ask.
First off, the front of the lens to show the diameter of the central obstruction and how much glass there is around it. (It doesn't look that dirty usually! I presume it's the light highlighting all the dust.)
Second, the depth of the primary lens from the front of the body. It's actually about 10mm, not the 5mm I mentioned before.
Lastly, the outside of the body, showing the 5mm gap between the end of the lens body and the fully retracted dew shield / light guard.
I had to scale them down a long way to fit under the file size restriction here. Let me know if you need bigger images and I'll get them to you.
It's a very hefty contraption, that's for certain. I never thought to measure how thick it was, so I'll agree that it looks about 2mm thick from the photos.
As for the damage, you can see it in my post in page 1 of this thread. The top-down view I gave doesn't really show it clearly.
Just a quick update - Bojan's had a look at the lens and his magic tool isn't able to straighten the thread. When the lens got dropped, the impact both bent the threaded area and squashed the threads, so rolling the dent out will not restore the thread.
My option now is to perform surgery on the lens to remove all the internals and then have the lens body machined down a bit to remove the damaged section.
This will also give me the opportunity to see if any of the internals are out of position and hopefully restore the optical qualities of the glass and mirrors.
