cleaning dust off 17-35mm f2.8 inner elements
Recently, the plastic ring with "Ultrasonic" printed on it
(in front of wider rubber zoom ring)
popped out of place, probably due to 100F heat;
immediately snapped it back in place without investigating what was exposed...
but am wondering if I can get at inner element dust
by popping it off again temporarily, then pssssst, psssst
canned air...? Do I risk alignment issues? Advice appreciated.