This mini-article is showing how to open Light Lens Lab 1.4x viewfinder magnifier for Leica M
LLL 1.4x magnifier is an excellent alternative to few times more costly Leica 1.4x magnifier, and many shooters prefer it also for compact size and for convenient diopter correction. My copy is excellently made with proper stiffness of diopter corrector ring that stays in place great. In some copied though the rotation of diopter ring is quite loose, which leads to frequent accidental rotation and missing optimal setup.
Disassembly
First remove thread adapter and attach the stock rear cap to the LLL 1.4x magnifier, remove rubber eyepiece cover. Then use one rubber band and wrap it around magnifier base together with rear cap for a good grip. Use another rubber band to unscrew the retention ring (you may use spanner wrench, but I prefer to keep the surface clean without accidental dents from spanner wrench).
Once retention ring is unscrewed, pull out the smaller cylinder - it is the diopter control ring.
You will notice factory grease. For more stiff rotation you will need to clean up all grease and replace it with one with higher viscosity level.
There are two grooves on the inner side of diopter ring that need to match two brass pins during assembly. It's visible from here that diopter ring and most likely all magnifier body is made of durable brass. In case you have scratches on surface they can be easily darkened by e.g. Birchwood Casey acid.
