Ring USM or not

Started Sep 19, 2006 | Discussions thread
Lemming51
Lemming51 Forum Pro • Posts: 15,225
Re: Ring USM or not

Skyspotter wrote:

Hello all
i have done a search but i didnt have any luck, i have seen some
second hand lens for sale with USM focusing, i have read that there
two types ring type (the good one) and not ring type.
How do i tell the difference???

http://www.usa.canon.com/app/pdf/lens/EFLensChart.pdf
However, it is not reliable as there are several errors in the chart.

Generally, all the L USM lenses are ring-USM with either mechanical or powered full time manual focus (FTM). All of the USM primes are ring-USM, except for the EF 50 f/1.4 USM which is micro-USM but still has FTM.

Among the consumer zooms, ring-USM lenses with FTM will have inner- or rear-focusing (non-rotating front element) and the USM label and ring on the lens will be gold colored. These lenses are:
EF-S 10-22 f/3.5-4.5 USM
EF-S 17-85 f/4-5.6 IS USM
EF-S 17-55 f/2.8 IS USM
EF 24-85 f/3.5-4.5 USM
EF 28-105 f/3.5-4.5 USM I, II
EF 28-135 f/3.5-5.6 IS USM
EF 70-210 f/3.5-4.5 USM (discontinued)
EF 100-300 f/4.5-5.6 USM
EF 70-300 f/4.5-5.6 DO IS USM

Micro-USM lenses that do not have FTM usually have silver USM label and barrel stripe:
EF-S 18-55 f/3.5-5.6 USM
EF 28-80 f/3.5-5.6 USM I, II, III, IV
EF 28-90 f/4-5.6 USM I, II
EF 28-105 f/4-5.6 USM
EF 75-300 f/4-5.6 USM I, II, II
EF 75-300 f/4-5.6 IS USM
EF 70-300 f/4-5.6 IS USM

 Lemming51's gear list:Lemming51's gear list
Canon EOS 40D Canon EF 50mm F1.8 II Canon EF-S 15-85mm f/3.5-5.6 IS USM Canon EF 70-200mm f/2.8L USM Canon EF-S 55-250mm f/4-5.6 IS STM +5 more
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