Canon lens with a catch
One thing you could try after putting the screws tight again is to put a dap of nail varnish over the head with just enough to go on to the part the head sits into. Hopefully that will have enough resistance to stop the heads from coming loose again, but not so much of a lock than if you used loc-tight on the actual screw threads. Which might be problem if the lens needed to be opened up for cleaning or service in the future.
|Orange-tip Butterfly by anisah|
from Nature's Colour Palette
|Windswept juniper by Kreber|
from Wind power