07-02-2021 10:43 PM
07-02-2021 10:48 PM
07-03-2021 09:38 AM
"For most Canon lenses macro just means close."
The word "macro", in this case, is a term created by the advertising department. Probably the biggest issue with these old or very old lenses is the lube gets dried out or sticky and otherwise doesn't, well, lube any longer. Some can be cleaned and re-lubed.
One other big factor is fungus. It tends to grow on the lens's surfaces. It is very difficult to impossible to remove.