M42x1 female to M39x1 (LTM) male thread adapter, infinity, rim

• Front side - M42x1 female thread
• Rear side - M39x1 male thread

This adapter allows using lens with universal M42x1 thread mount on rangefinder cameras with M39x26tpi thread (also known as LTM, Leica Thread Mount, L39) like old Leica, FED, Zorki.

Infinity focus is preserved.

The adapter consists of three parts:

• the base with the LRM male thread;
• the insert with the M42x1 female thread;
• the instant return diaphragm pressing rim.

This design allows the following features:

• infinity focus of M42x1 lenses on the corresponding cameras;
• adjusting the position of the lens witness mark if necessary;
• adjusting the position of the pressing rim (this may be necessary since I had M42x1 lenses that need 1.5mm different axial position of the point where the pin is pressed completely);
• removing the rim (this may be necessary for some lenses like Meteor 5-1, that can't be installed if the pressing rim is there).

Machined from high quality aluminium alloyWhy aluminium?.