The Canon EF 17-40mm f/4L USM Lens is an ultra wide-angle zoom lens that offers excellent image quality and a constant maximum aperture. Its compact, lightweight body makes it an ideal travelling companion.
- Superb optical performance throughout the zoom range
- Fast autofocus speed
- Highly resistant to dust and moisture
- 28cm minimum focusing distance at all focal lengths
Ultra-wide or standard zoom
The EF 17-40mm f/4L USM acts as an ultra-wide angle zoom on film or full-frame digital EOS cameras. On DSLRs equipped with APS-C sized sensors it acts as a standard zoom, giving an angle of view equivalent to a 28-70mm lens on a full-frame camera.
Minimum focusing distance is just 28cm throughout the entire zoom range.
Superior optical performance
The EF 17-40mm f/4L USM has 12 lens elements arranged in nine groups. Super Spectra coating ensures excellent colour balance and minimises ghosting and flare. To provide superb image quality over the complete 17-40mm zoom range the lens uses three aspheric elements. Super UD (Ultra-low Dispersion) glass prevents chromatic aberrations.
A ring-type ultrasonic motor drives autofocus extremely quickly, and in near silence. Excellent holding torque ensures the point of focus is reached accurately, without overshooting. Furthermore, full-time manual override is available, making it possible to adjust focus without leaving AF mode.
Non-rotating front element
The front of the lens does not rotate, which makes using specialised filters, such as polarisers and graduates, easier. A drop-in gelatine-filter holder can be found at the back of the lens.
Smooth background blur
A virtually circular aperture diaphragm gives out of focus regions a softer, more uniform feel. Sharp foreground objects stand out against a smooth blurred background.
Highly resistant to moisture and dust, the EF17-40mm f/4L USM is ideally suited for use in harsh environments. Environment friendly lead-free glass is used throughout its construction.
|Angle of view||Horizontal: 93° - 49°20'
Vertical: 70°30' - 34°
Diagonal: 104° - 57°30
|Lens construction||12 elements in 9 groups|
|No. of diaphragm blades||7|
|Closest focusing distance||0.28m|
|Max. diameter x length||83.5 x 96.8mm|
- Canon EF 17-40mm f/4L USM Lens
- E-77U Lens Cap
- Rear Dust Cap E
- EW-83E Lens Hood
- LP1319 Soft Case