Canon EF 50-200mm f/3.5~4.5L zoom lens

The EF 50-200mm f/3.5-4.5L has no USM configuration , instead, it incorporates an Arc-Form Drive (AFD) motor for all of its autofocus operation and thus, manual focusing during AF operation is not possible. Manual focusing is possible via switching the mode switch to "M" where you find the MACRO setting is also located. The Electromagnetic Diaphragm (EMD) control eliminates any mechanical linkage with most new/old EOS cameras. Similar to the standard consumer version, this L-lens also uses popular 58mm filters.

Canon EF 50-200mm f/3.5~4.5L zoom lens

This high-performance zoom lens joins Canon's professional line of 'L' series lenses and features superior optical performance by utilizing two fluorite glass elements. It is compact and lightweight, with a 4X zoom ratio covering the standard to telephoto focal lengths. The single push and pull zoom control ring also offers full range macro mechanism allows focusing as close as 4 feet with a magnification power of 0.23X (Macro: 1.2m (3' 11-1/4"); Normal: 1.5m (4' 11").

Technical Specification for Canon EF 50-200mm f/3.5~4.5L AFD Standard-to-Telephoto-Zoom: -

Type: - Autofocus standard-tele zoom lens type
Focal Length: Variable zoom range from 50mm- 200mm
Focus Adjustment:- Autofocus type
Manual Focusing:- possible via AF/M switch; Full time Manual focusing NOT possible
Zoom Adjustment:- Ring controlled zoom action via zoom ring control with indicator zoom range 50mm, 70mm, 100mm,135mm & 200mm
Closest Focusing Distance:- 1.2m (3.9 ft) MACRO setting: indicated via M switch (Closest Focusing Distance: macro 3' 11-1/4"'(1.2m) normal 4' 11" '(1.5m) 
Maximum Magnification:- 0.23X
AF Drive (motor) System:- AFD (Arc Form Drive)