The newest design product, lens adapter combine helicoid macro tube. Support both MACRO SHOOTING with helicoid adjust and INFINITY FOCUSING.The length of this adapter is 14mm(min.) to 22mm (max.).It allows you to take close up/macro image more easier when full extended. It can focus infinity when closed of course. It is fit for the Leica M lens on the Canon EOS R camera body, saving you the expense of a costly and irreversible conversion. The adapter has no lens element so it does not effect optical performance. Vignetting may occur in full frame cameras. Switching on "Release shutter without lens" in custom menu C.Fn5, then switching shooting mode to M (manual) is recommended. Not suitable for Canon EOS film / digital SLR cameras and EOS M series EF-M mount mirrorless cameras. Focusing Reference28mm with minimum focus distance of 0.7m was able to focus at 0.2m -------- ELMARIT 28/2.8 ASPH35mm with minimum focus distance of 1m was able to focus at 0.28m -------- SUMMILUX 35/1.4 V150mm with minimum focus distance of 1m was able to focus at 0.43m -------- SUMMILUX 50/1.4 V1,NOCTILUX 50/1 V2,50mm with minimum focus distance of 0.75m was able to focus at 0.38m ----- SUMICRON 50/2 V575mm with minimum focus distance 1.2m was able to focus at 0.73m ----------- HEKTOR 73/1.990mm with minimum focus distance 1m was able to focus at 0.73m -------------- SUMMICRON 90/2 V3It is advanced model which have large focusing , you can easily to focus and more accurate.