First, you have to turn the focusing ring until infinity, so the rear glass will move to its maximum outside reach .
Now, make a kind of cardboard bridge, we don't want anything metallic or too hard near our Leica glass.
For my calculations, the "legs" could be 10.2 mm long, but I made them a bit shorter to be on the safe side.
As you can see, the rear Leica lens glass itself will not hit the Sigma's camera body internal dust-protection window.
But the Leica lens barrel protective ending will.
Measure how much the rear end of the barrel has to be grounded off and make a mark at the both sides with a needle.
Now we have to protect the lens, I use raw cotton that also will trap metallic particles.
Also I use a piece of paper tape that will make possible to file it easily.
Now, we can start filing until we reach the marks.
When you reach the marks, turn the lens upside down and remove the cotton protection.
Remove the few metal particles that trespassed the protection.
I use our plastic tool wrapped with cotton.
Now check the result with your cardboard bridge.
I painted the exposed metal with my flat black marker from Micro-Tools.
Painted, now we can remove the Leica bayonet and install the Leica-Sigma one.
And you can see in this picture the Elmarit 28/2.8 reaching infinity without any problem on Sigma cameras.
Back to Leitax
Back to Nikon page