Canon EF17-40mm f/4L USM Manual

The Canon EF17-40mm f/4L USM is a highperformance wide-angle zoom lens.

• "USM" stands for Ultrasonic Motor.

Conventions used in this instruction

	Warning to prevent lens or camera malfunction or damage.
	Supplementary notes on using the lens and taking pictures.

Features

1. Two aspherical elements and a Super UD element result in outstanding image delineation.
2. Ultrasonic motor (USM) for quick and quiet autofocusing.
3. Manual focusing is available after the subject comes into focus in autofocus mode (ONE SHOT AF).
4. A truly round aperture hole results in a nicer background blur.
5. Tight seal structure ensures excellent dustproof and drip-proof performance.
   • Since the front element of this lens moves when focusing (zooming), you need to attach a Canon PROTECT filter sold separately for adequate dust- and water-resistant performance. Without a filter, the lens is not dust or water-resistant.

Nomenclature

Mounting and Detaching the Unit

See your camera's instructions for details on mounting and detaching the lens.

• After detaching the lens, place the lens with the rear end up to prevent the lens surface and electrical contacts from getting scratched.
• If the contacts get soiled, scratched, or have fingerprints on them, corrosion or faulty connections can result. The camera and lens may not operate properly.
• If the contacts get soiled or have fingerprints on them, clean them with a soft cloth.
• If you remove the lens, cover it with the dust cap. To attach it properly, align the lens mount index and the O index of the dust cap as shown in the diagram, and turn clockwise. To remove it, reverse the order.
  

The lens mount has a rubber ring for enhanced water- and dust-resistance. The rubber ring may cause slight abrasions around the camera's lens mount, but this will not cause any problems. If the rubber ring becomes worn, it is replaceable by a Canon Service Center at cost.

Setting the Focus Mode

To shoot in autofocus (AF) mode, set the focus mode switch to AF.
To use only manual focusing (MF), set the focus mode switch to MF, and focus by turning the focusing ring. The focusing ring always works, regardless of the focus mode.

After autofocusing in ONE SHOT AF mode, focus manually by pressing the shutter button halfway and turning the focusing ring. (Full-time manual focus)

Zooming

To zoom, turn the lens' zoom ring.

Be sure to finish zooming before focusing. Changing the zoom ring after focusing can affect the focus.

Infinity Compensation Mark

To compensate for shifting of the infinity focus point that results from changes in temperature. The infinity position at normal temperature is the point at which the vertical line of the L mark is aligned with the distance indicator on the distance scale.

For accurate manual focusing on subjects at infinity distance, look through the viewfinder while rotating the focusing ring.

Infrared Index

The infrared index corrects the focus setting when using monochrome infrared film. Focus on the subject manually, then adjust the distance setting by moving the focusing ring to the corresponding infrared index mark.

Some EOS cameras cannot use infrared film. See the instructions for your EOS camera.

• The infrared index position is based on a wavelength of 800 nm.
• The compensation amount differs depending on the focal length. Use the indicated focal length as a guide when setting the compensation amount.
• Be sure to observe the manufacturer's instructions when using infrared film.
• Use a red filter when you take the picture.

Hood

The EW-83E hood can keep unwanted light out of the lens, and also protects the front of the lens from rain, snow, and dust.
To attach the hood, align the hood's attachment position mark with the red dot on the front of the lens, then turn the hood as shown by the arrow until the lens' red dot is aligned with the hood's stop position mark.
The hood can be reverse-mounted on the lens for storage.

• Part of the picture may be blocked if the hood is not attached properly.
• When attaching or detaching the hood, grasp the base of the hood to turn it. To prevent deformation, do not grasp the rim of the hood to turn it.

Filters

(Sold separately)
You can attach filters to the filter mounting thread on the front of the lens.

• To ensure dust- and water-resistant performance, attach a Canon PROTECT filter (77mm).
• Only one filter may be attached.
• If you need a polarizing filter, use the Canon Circular Polarizing Filter (77mm).

Filter Holder

There is a gelatin filter holder at the rear of the lens. Cut the gelatin filter to fit within the white frames. Then insert the gelatin filter into the filter holder.

• Only one filter can be used.
• When you use a gelatin filter, ghosting may appear in the image.

Extension Tubes

(Sold separately)
You can attach Extension Tube EF12 II or EF25 II for magnified shots. The shooting distance and magnification are shown below.

Manual focusing is recommended for accurate focusing.

Close-up Lenses

(Sold separately)
Attaching a 500D (77mm) Close-up Lens enables close-up photography.
The magnification will be as follows:

• Can be used at the 40mm end (magnification 0.30x - 0.08x)

• Close-up Lens 250D cannot be attached because there is no size that fits the lens.
• Manual focusing is recommended for accurate focusing.

Specifications

• The lens length is measured from the mount surface to the front end of the lens. Add 21.5 mm when including the lens cap and dust cap.
• The size and weight listed are for the lens only, except as indicated.
• The EF1.4X II/EF2X II extenders cannot be used with this lens.
• Aperture settings are specified on the camera.
• All data listed is measured according to Canon standards.
• Product specifications and appearance are subject to change without notice.

Safety Precautions

Safety Precautions

• Do not look at the sun or a bright light source through the lens or camera. Doing so could result in loss of vision. Looking at the sun directly through the lens is especially hazardous.
• Whether it is attached to the camera or not, do not leave the lens under the sun without the lens cap attached. This is to prevent the lens from concentrating the sun's rays, which could cause a fire.

Handling Cautions

• If the lens is taken from a cold environment into a warm one, condensation may develop on the lens surface and internal parts. To prevent condensation in this case, first put the lens into an airtight plastic bag before taking it from a cold to warm environment. Then take out the lens after it has warmed gradually. Do the same when taking the lens from a warm environment into a cold one.
• Do not leave the lens in excessive heat such as in a car in direct sunlight. High temperatures can cause the lens to malfunction.

Documents / Resources

Download manual

Here you can download full pdf version of manual, it may contain additional safety instructions, warranty information, FCC rules, etc.

Download Canon EF17-40mm f/4L USM Manual