Canon 1.4X Extender EF II

Lens Reviews / Canon Lenses i Lab tested
1.4x $349
average price
image of Canon 1.4X Extender EF II

Lab Test Results

  • Blur
  • Chromatic Aberration
  • Vignetting
  • Geometric Distortion

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Buy the Canon 1.4X Extender EF II

SLRgear Review
October 3, 2011
by Andrew Alexander

The Canon 1.4x lens extender extends the focal length of a lens by 40%, making (for example) a 200mm lens function as a 280mm lens. The 1.4x series was introduced 1988, and updated in 2001 with the version II model, the subject of this review.

Canon lens extenders were designed in the era of film, making them fully compatible with full-frame, APS-H and APS-C EOS digital cameras. The trade-off to the 40% extended range of the extender is the loss of one stop of light-gathering ability of the lens: accordingly, an ƒ/2.8 lens will operate as a ƒ/4 lens.

The 1.4x II Extender, while technically superceded by the newer version III Extender, is still available now, for around $320.

We'd like to thank for their loan of this extender for our testing: to rent this lens, click here.

We used Canon's 200mm ƒ/2.8L II USM telephoto lens to test the 1.4x II Extender, comparing the sharpness of the lens with and without the extender attached. Without the extender, the lens shows very good results at ƒ/2.8, becoming almost tack-sharp at ƒ/4 through to ƒ/11.

With the Extender attached, sharpness is slightly reduced, especially in the corners. You'll never get tack-sharp results with the 1.4x II Extender attached, but decent performance is still obtained at ƒ/5.6, where things are more or less even across the frame.

It's worth noting that you can stop down to ƒ/45 with the Extender attached, but you won't want to, as images are distinctly soft at this setting.

Chromatic Aberration
There is a noticeable increase in chromatic aberration introduced by the 1.4x II Extender, at all apertures; you'll want to consult our sample images for more detail.

Shading (''Vignetting'')
Using the 1.4x II Extender alleviates corner shading noticed without the use of the extender, at the ƒ/2.8 setting, but that's only because the ƒ/2.8 aperture is no longer available. Technically, you're still shooting the lens at its f/2.8 aperture, but the extender is focused on the center region of the glass, where shading does not reach. At the widest setting of ƒ/4, the corners are only a 1/4 stop darker than the center.

The 200mm ƒ/2.8L offers light barrel distortion in the corners and overall, very light pincushion distortion: adding the 1.4x II Extender to achieve 280mm introduces barrel distortion throughout the image (to a maximum of +0.5% barrel distortion in the corners).

Autofocus Operation
In our usage of the 1.4x II Extender, we did not really notice a significant impact on the autofocus performance of the 200mm ƒ/2.8L II USM lens, which is fast and snappy all on its own. However, Canon warns that there is an impact on autofocus performance with type II and III Extenders. Specifically, Canon suggests that AF drive speed is reduced by 50% when using the 1.4x Extender.

The 1.4x Extender has some useful implications in macro work, offering an extra 40% magnification without sacrificing the minimum close-focusing distance; in the case of the 200mm ƒ/2.8L II USM, this results in 0.22x magnification instead of 0.16x magnification.

Build Quality and Handling
The Canon 1.4x II Extender is heavy for its size, at just under 8 ounces, suggesting a fair amount of metal in its construction. The finish of the lens is white, to match Canon's upper-tier L-class telephoto lenses, for which the lens is designed to be paired. The design of the lens is quite simple, 4 lens elements in 5 groups, and there is only one control surface on the extender: a switch to release an attached lens. The extender can be combined with the 2.0x Extender for a significant increase in focal length, but at the cost of significant reduction in light-gathering ability: you would lose three stops of light for an additional 240% in focal length, making your 200mm ƒ/2.8 lens the equivalent of a 480mm ƒ/8 lens.


As this is our first foray into teleconverter testing, we have no other tests to compare with, but here is a list of the current alternatives in the 1.4x category:

Canon 1.4X Extender EF III ~$480

Sigma 1.4X EX DG APO ~$250

Tamron 1.4X SP AF PRO ~$225

Kenko 1.4X Teleplus PRO 300 DG AF ~$250

Of course, the question all of you will be asking is: how does the 200mm ƒ/2.8 with the 1.4x Extender attached, compare with the 300mm ƒ/4L IS USM? The irony is that we haven't yet tested that lens, but we've put it on our list to review so we can draw that conclusion.

These days, the question might be whether it is as useful to use a 1.4x Extender as opposed to an APS-C camera body, which offers an equivalent of 1.6x extension of the focal length, with no impact on image quality. In its own right, the 1.4x is a good optic: there is some slight impact on overall sharpness and chromatic aberration, and a slight impact on distortion, but otherwise, overall image quality is still very good.

Product Photos

Sample Photos

The VFA target should give you a good idea of sharpness in the center and corners, as well as some idea of the extent of barrel or pincushion distortion and chromatic aberration, while the Still Life subject may help in judging contrast and color. We shoot both images using the default JPEG settings and manual white balance of our test bodies, so the images should be quite consistent from lens to lens.

As appropriate, we shoot these with both full-frame and sub-frame bodies, at a range of focal lengths, and at both maximum aperture and ƒ/8. For the ''VFA'' target (the viewfinder accuracy target from Imaging Resource), we also provide sample crops from the center and upper-left corner of each shot, so you can quickly get a sense of relative sharpness, without having to download and inspect the full-res images. To avoid space limitations with the layout of our review pages, indexes to the test shots launch in separate windows.

Canon 1.4X Extender EF II

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Canon 1.4X Extender EF II User Reviews

9.6/10 average of 7 review(s) Build Quality 9.9/10 Image Quality 9.4/10
  • 10 out of 10 points and recommended by charley (6 reviews)
    light and very well built

    I use this with my 70-200 L f/4 IS USM. When attached this lens compliments my lens very nicely and takes some excellent pictures. IQ is fantastic, build quality is great.

    reviewed September 2nd, 2010 (purchased for $299)
  • 10 out of 10 points and recommended by climber (11 reviews)
    The best TC, allmost no loss in IQ when used with prime lenses

    This TC is amazing. I use it a lot with my 200mm f2.8 L prime. There is allmost no loss of image quality.

    Superb piece of equipment.

    reviewed April 22nd, 2009 (purchased for $350)
  • 10 out of 10 points and recommended by Badmono (15 reviews)
    Killer piece of kit for use with 'L' primes - You must have one
    None whatsoever

    Used with 'L' series primes this convertor works fantastically well, IQ and sharpness lose nothing from the standard lens.
    A no brainer - just buy one if you use 'L' series primes
    Doesn't work well with 'Hell' ZOOMs but hey Zooms are for snappers only, this convertor merely magnifies their shortcomings

    reviewed December 1st, 2008 (purchased for $250)
  • 9 out of 10 points and recommended by hitendra (11 reviews)
    Build & Image quality

    I am mostly using this with 70-200/4 IS here are the results

    reviewed October 24th, 2007 (purchased for $299)
  • 9 out of 10 points and recommended by mxwphoto (12 reviews)
    Weather sealing, solid construction
    Pricier than competition

    I have this TC mated to my 100-400L. There's nothing to complain at all here! The build is as solid as the best L lenses, it includes a weather sealing O-ring, and the image degradation is minimal. In fact, I have to squint hard between an image with and without the TC to even notice a difference at 100%(other than one being more magnified, that is). For those who worry about having a lens that will stop af because it's not f/2.8, simply do a tape mod and things will work well again. The only downside to this TC is that its 3rd party competitors can be had at similar optical qualities for roughly $100 less. But then again, they lack the solid L build and weather sealing. You do get what you pay for!

    reviewed January 2nd, 2007 (purchased for $260)
  • 10 out of 10 points and recommended by garys (12 reviews)
    minimal loss of image qualilty
    none for what it is

    Modest impact on image quality over the naked lens, especially for primes. My experience is generally that lens magnification of any type produces better results than enlarging in post processing.

    reviewed January 1st, 2007 (purchased for $250)
  • 9 out of 10 points and recommended by mebailey (21 reviews)

    I bought to use with my 100-400L. It is a high quality piece of glass but does noticebly degrade the image on that lens. I have used it on my 180mm macro with better results. I understand that it even works better with Canon super teles but have not tried it myself.

    reviewed December 14th, 2006
  • 10 out of 10 points and recommended by terryf (10 reviews)
    Greater reach with minimal loss of image quality.

    Well over half of the images that I capture with my 300mm L f4 IS lens are made with the 1.4x Extender mounted. Any loss of image quality is very minimal. It is important to note that both AF and IS are maintained when I use this combination on my 20D. It is true that the AF does seem to take a little longer to find focus when the Extender is mounted but that has not been a big problem, even when photographing wildlife. The only real disadvantage that I can see is the loss of a stop in speed but even that is minimized since I have IS on the lens. I find that I can use this combination handheld quite effectively. Interestingly, I have never found any reason to use the teleextender on any of my other lenses. The purpose of this accessory is to obtain greater reach and so it is only used on the longest lens that I own.

    reviewed December 4th, 2006 (purchased for $280)