Out of curiosity, are you in the neuro field with photography being your hobby or something?
Yes and yes.
I read the Canon release on the new EF-S 55-250 zoom and there is no mention of USM, so it has the painted silver ring.
If a lens has USM, it will always be in the full name of the lens (for an overview, see the EF Lens Lineup page
But, even that doesn't tell the whole story. Ultrasonic means the AF motor is silent (from a human hearing perspective, at any rate), but there are two kinds of USM - micromotor USM and ring USM. Of the two, ring USM is superior, and is what's found in L-series lenses, DO lenses, and the better quality non-L lenses. Ring USM is faster than micromotor USM, and often more accurate. Micromotor lenses focus more slowly, and usually do not offer full-time manual focusing (meaning you need to switch the lens to MF before moving the focus ring, else you may damage the lens).
To find out which type of USM a particular lens has, you usually need to dig into reviews (e.g. TDP
) or specs page (e.g. PhotoNotes
). For a few examples, the 28-135mm f/3.5-5.6 IS USM lens has ring USM, whereas the 70-300mm f/4-5.6 IS USM has micromotor USM. All five of the EF-S lenses with USM have the ring-type USM. The 85mm f/1.8 USM has ring USM, whereas the 50mm f/1.4 USM has micromotor USM (although it has a unique clutch mechanism to allow full time manual focusing, which is probably one of the reasons the lens' AF system is reportedly prone to breaking).