Canon's full-frame, wideangle-to-fisheye zoom lens attempts to offer more than just a one-trick effect. Mat Gallagher finds out whether this lens really should have a place in your kit bag
Features and build
The styling of this 8-15mm lens is in keeping with other L-series zooms, with the signature red ring around the barrel. The zoom ring sits at the back and offers a fairly free adjustment of less than a quarter of a turn. However, with both internal focusing and focal length adjustment, there is no need to worry about lens creep.
The manual focus ring sits at the front of the lens and is only very slim, as this lens is less likely to be operated in manual mode for the majority of users. The autofocus employs a ring ultrasonic motor (USM) for fast and quiet operation, and manual override always remains active should it be required. The focus window shows the small adjustment in focus point required for the widest 8mm focal length in red.
The front element is extremely concave and is protected by a removable lens hood, over which the lens cap attaches. Due to this large, domed front element there is no filter thread available, nor is there a rear filter slot, although with an APS-C sensor it is possible to cover the field of view with a standard square filter – if held in front of the lens.
The construction is fairly complex, comprising 14 elements in 11 groups including one aspherical and one ultra-low dispersion element. All elements are coated with Canon’s Super Spectra coating to reduce ghosting and flare, while the inside of the front element also features a subwavelength structure coating (SWC). The front and rear elements have a fluorine coating for water resistance.
At its 8mm setting, the lens offers an 180° field of view, although for APS-C and APS-H cameras this view is cropped, mostly in the vertical axis. The aperture maintains a constant f/4 maximum, which is more than adequate for a lens this wide, and with a minimum focus of just 15cm, a very shallow depth of field is achievable. As with most L-series optics, the mount includes a rubber ring to seal the unit against moisture and dust when attached to the camera body.