To paraphrase an estimable poster who undoubtedly knows, "Your 'zoom'
lens is in fact 'varifocal', meaning that the point of focus changes as
you zoom. ... A true zoom lens does not do this."
Alternatively, how many "True zoom" lenses are in use by contributors to
I posted a quotation from Mr Canon's polyglot leaflet included with the
EF24-70mm f/2.8L USM lens (not cheap):
"(!) · Be sure to finish zooming before focusing. Changing the zoom ring
after focusing can affect the focus."
There's one instance of non-true zoom confessions. Any others?
Is the effect of any practical ...