Canon EF 200-400/4L IS USM Extender Review

The Canon EF 200-400/4L IS USM Extender is a unique lens in that it’s the only DSLR lens that I know of that has a 1.4x extender built-in. This changes the normal range of 200-400mm at f4 to 280-560mm at f5.6. The built-in extender has a number of advantages over the normal “add-on” extender:

1 – It’s faster. It takes just a fraction of a second to flip the lever from the 1x position (no extender) to the 1.4x position. Compare this with the time to remove the camera body from a lens, add on an extender, and remount the camera body. For situations where you are capturing action (e.g. Sports and Wildlife photography), this can be the difference between getting a shot and missing it. Essentially, it makes the lens a 200-560mm zoom.

2 – It’s safer. Not only is there no risk of dropping lenses while adding an extender, there’s no risk of dust, dirt, or rain getting into the camera while removing and replacing lenses when operating in adverse environments.

3 – Image quality. Normal extenders are made to work with a variety of lenses. For example, the same extender is used with the Canon 70-200/2.8L IS USM as with the 400/4 IS DO and the 600/4L IS USM (as well as the various other 300, 400, and 500mm lenses). There must inevitably be some degree of optical compromise with having to match so many different lenses. With the extender built into the 200-400/4L IS USM Extender, the optics only have to match those of the original lens and so can be optimized for that specific application.

4 – The extender is always with you, so you can’t lose it or the caps! It’s one less thing to think about when operating in a busy environment.

There is the question of why a 200-400mm lens. Why not a 200-500mm or 200-600mm or even 100-400mm? Why f4, not f2.8? Well, if you take a look at the specifications of the 200-400/4L IS USM Extender, you’ll see that it weighs 3.6kg (almost 8lbs). It’s 5" in diameter and 14.4" long. This isn’t a small lens, nor is it a light lens. In addition, it’s not an inexpensive lens either, with a current retail price around $11,800.

Anything faster and longer would be heavier and more expensive. Sigma has a 200-500/2.8 that weighs almost 35lbs and costs $26,000. I’d imagine a Canon “L” IS version of that might be closer to $35,000.

It appears that Canon designed this lens for professional and wealthy amateur Sports and Wildlife photographers. It can be handheld for short periods of time, and the zoom range of 200-560mm covers the range such photographers might be expected to use most.

The 200-400/4L IS USM is comparable in size and weight to the 500/4L IS USM. It’s just 3/4" shorter and 8oz lighter (but it costs $1300 more!).

Canon EF 200-400/4L IS USM Extender Specifications

Focal Length & Maximum Aperture Built-in extender at 1x: 200-400mm, 1:4.0
Built-in extender at 1.4x: 280-560mm, 1:5.6
Lens Construction Built-in extender at 1x:
25 elements in 20 groups (incl. 1 rear filter)
Built-in extender at 1.4x:
33 elements in 24 groups (incl. 1 rear filter)
Diagonal Angle of View Built-in extender at 1x: 12°-6°10’
Built-in extender at 1.4x: 8°50’-4°25’
Focus Adjustment Inner focusing system
Closest Focusing Distance 6.6 ft / 2m
Filter Size 52mm drop-in
Max. Diameter x Length, Weight 5.0 × 14.4 inches, 127.7oz / 128 × 366mm, 3620g

Top: EF 200-400/4L IS USM Extender; Bottom: EF 300/4L USM

The EF 200-400/4L IS USM Extender is by no means a small or light lens. As mentioned above, it is just fractionally smaller and lighter than Canon’s EF 500/4L II IS USM. You certainly can use it without a tripod, but at close to 8lbs in weight, it’s not really a lens you’d want to handhold unless you had to. While I have shot with it handheld for short periods of time, I’d imagine that after a while you’d wish you had a tripod with you (or at least a monopod).

The close focus distance of 2m is pretty good for a long telephoto, though not as short as some primes in the 200mm to 400mm range. I measured maximum magnification (560mm at closest focus) to be about 0.22×.

At the front of the lens is a black rubber ring with 4 buttons. This ring does not rotate but has the 4 AF stop buttons that can be used to hold AF. For example, this can be useful when something comes between the lens and the subject while AF tracking.

Just behind this is a white knurled ring that rotates though a short arc. This has two functions. One is to go to a preset focus position. The other is to control the power focus option for video. In power focus mode, rotating this ring slowly and smoothly shifts focus.

Behind this is a wide black rubber zoom ring that selects the desired focal length. Finally, there is another narrower rubberized ring that is used for manual focus.

There are three focus modes: manual focus, power focus, and autofocus. Power focus is typically used in video applications and allows slow, smooth electronic focusing via manual control as explained above.

There are three focus ranges, 2m to infinity, i.e. the full range. When you know your subject will be close, use 2m to 6m, and when you know your subject won’t be close, use 6m to infinity. The reason for limiting the range is to improve focus acquisition speed since it limits the range the lens has to search though if focus is lost for some reason.

Measured focus time from close focus to infinity (or vice versa) was around 0.5 seconds at 200mm to 0.56 seconds at 400mm. Switching in the 1.4x extender significantly slowed focus to around 1.2 seconds from close focus to infinity. Of course these are worst case times. Rarely would the lens be searching through its entire focus range. With the range limiter set for 6m to infinity, the focus time at 400mm with the extender switched in dropped from 1.2 seconds to 0.7 seconds, and without the extender, the focus time dropped to 0.4 seconds. These, again, are worst case values. In fact, AF in most practical situations was very fast indeed.

Focus with the lens I had and my EOS 7D seemed to be spot on with no microadjustment needed.

I made a few focal length measurements at a distance of 50m. I have previously calibrated my 500/4.5L USM lens’ focal length as being 500.15mm, so I used this as my reference measurement standard. At a setting of 200mm, I measured a focal length of 203mm. At 400mm, I measured a focal length of 382mm, and at 400mm with the 1.4 extender inline, I measured 537mm (a multiplier factor of 1.406x). These numbers are within the +/-5% that’s considered normal for focal length tolerance.

A distance of 50m should be a long enough that any difference at infinity focus should be very small. Just about all zooms exhibit “focus breathing” when close focused, i.e. their effective focal length becomes shorter at short focus distances. I would expect the 200-400mm to do this also. A quick “back of the envelope” calculation when close focused (2m) at 560mm (0.22x) gave a ballpark figure of around 325mm for the effective focal length.

The built-in extender engages via a simple lever on the side of the lens. There’s a lock that can either lock it in the out position (1x) or the in position (1.4x)

Image stabilization is turned on or off via a slide switch on the side of the lens. There are three selectable modes. Mode 1 is the normal IS mode for when the lens is in a fixed position. Mode 2 is the usual mode used for panning, which turns off stabilization in the direction in which the lens is being panned. Mode 3 is a new mode that is similar to mode 2 but that only activates when the shutter is fully depressed to allow for more accurate framing of subjects when panning at high speed.

Below the IS controls is the focus preset control. It allows a focus position to be recorded with the push of a button and returned to with the slight rotation of the focus preset ring (see above), with or without a confirmation “beep.”

The EF 200-400/4L IS USM Extender takes rear mounted “drop-in” 52mm filters. On a camera like the EOS 7D, with a built-in flash, it’s necessary to remove the camera from the lens in order to remove the filter. With an EOS 5D (MkI), the filter can be removed without removing the camera. Though I didn’t try it, it looks like that would also be the case with the EOS 5D MkIII.

The EF 200-400/4L IS USM comes with a sturdy plastic carrying case, along with a couple of carrying straps for the lens and an alternate tripod foot. The standard foot has mounting holes for both 3/8" and 1/4" threads. The smaller foot has a single mounting hole for 1/4" threads. The lens is supplied with a reversible hood and a Velcro fastening “cap.”

Image Quality

I’m not going to report extensive results from test charts here. The EF 200-400/4L is sharp enough wide open (both with and without the extender) that any working professional could market the images without any concerns about sharpness. It’s a sharp lens. Whether or not lenses like the 300/2.8L II IS USM or the 400/2.8 II IS USM are marginally sharper under ideal conditions is another issue. I suspect that on a optical bench that might be the case, but the difference is unlikely to be significant when the lenses are actually used in the field. I did compare the images at 560/5.6 with those from my EF 500/4.5L USM, and I’d judge them to be pretty much equally sharp. The 560/5.6 images have slightly lower levels of chromatic aberration at the edges of the frame.

Here’s a shot taken using an EOS 7D at 400mm with the extender in line (560mm f5.6):

And here’s a 100% crop of that image:

That’s at full zoom with the extender in and the lens wide open. Pretty sharp!

Here’s another example of 100% crop from a shot with a 7D, 560mm wide open at f5.6:

Chromatic aberration is very well controlled. Yes, at the corners of the image on high contrast edges, you can detect very slight color fringing, but it’s minimal in extent and consistent throughout the zoom range (including the extender). You’d have to be looking closely at the corners of large prints to even see it. I’d estimate the extent of the fringing at 560mm in the extreme corners of an APS-C frame at 2-3 pixels. Here’s an example:

The upper image is a 100% crop from the extreme corner of an image shot at 560mm and f5.6 with the extender in line, using an EOS 7D. If you look very closely, you can see slight green fringing on the left of the white section and slight magenta fringing on the right. You can also see slight green fringing on the top of the horizontal dark lines and slight magenta fringing on the bottom.

The lower image is a RAW image converted using Canon’s DPP program, with chromatic aberration correction enabled. There’s now essentially zero chromatic aberration visible.

Distortion is minimal, as you’d expect from a telephoto lens of this type. There’s the slightest hint of barrel distortion at 200mm and the slightest hint of pincushion distortion at 400mm, but you’d have to be shooting a rectangular grid and looking very hard to even see it—absolutely unnoticeable in normal images, even images of rectangular objects.

Vignetting wide open ranges from just under a stop in the corners of a full frame image at 200mm to a little over a stop at 400mm. At f5.6, it’s under 1/2 stop at all focal lengths, which is pretty much insignificant.

Image stabilization is very effective. Canon claims up to 4 stops at all focal lengths and that’s about right according to my testing. I typically saw 3 to 3.5 stops and sometimes 4 stops, depending on conditions and how long I’d been trying to handhold an 8 lb lens! Note that the 200-400 has a new IS mode which only engages IS when the shutter button is fully depressed. Canon states that this makes panning shots of moving subjects easier because you don’t see the effects of the IS “fighting” the panning movement but the image is still stabilized. I don’t know if this adds anything to shutter lag time since Canon made no comment on that.

Image Examples

Here are some examples taken with the EF 200-400/4L IS USM Extender mounted on an EOS 7D body:

Above is the shot at 200mm and f4. The background is pretty smooth and the sharpness is excellent.

This is with the lens zoomed out to 400mm, still at f4. Again, the background is smooth and the overall image quality is very high.

Finally, this is the view when the 1.4x Extender is switched into the optical path, making the lens 560mm at f5.6. There’s no visible degradation of the image quality and the background retains its smooth out-of-focus character.

Here’s a second series of shots, again taken with an EOS 7D:

This is the whole frame with the lens set to 400mm and the extender inline, i.e. 560mm at f5.6.

This is a crop of the section around the moon itself.

And finally here’s a 100% crop of the moon’s upper left (Sinus Iridum area).


While the EF 200-400/4L IS USM Extender already has an excellent built-in 1.4x extender, it is possible to add Canon’s EF1.4x III and 2x III. There’s really no point in adding the 1.4x III to the lens to go from 400mm to 560mm since the built-in extender does that job. With the built-in extender in the optical chain giving you 560/5.6, you can then add an external 1.4x to go to 784mm at f8. With Canon’s high-end full frame DSLRs you still get AF using the center AF zone. You can also add the 2x III to the lens without the built-in extender in the optical path to give you 800mm at f8 again, and again you will have AF via the center AF zone with the 1D X and 5D MkIII. With the built-in extender activated you can add the 2x to get you to 1120mm at f11, but that requires manual focus.

Of course extenders will slow down the focusing speed of the lens somewhat, so that is a consideration for action shots requiring focus tracking. For static subjects it is usually of little concern.


The canon_200-400ext is a unique and highly useful lens. While its optical quality is excellent, it’s really the versatility of the lens that makes it so useful. All the Canon “L” series telephoto lenses are fast focusing and optically very good indeed, but on top of that the 200-400/4L Extender is a lens that excels in its ability to cover a wide range of focal lengths from 200mm to 560mm in a single package. For photographers dealing with rapidly changing situations, such as sports, wildlife, and news photography, that’s something that can mean the difference between getting a great shot and missing it entirely. In such situations it’s often not possible to switch lenses or add an extender without missing critical action. The ability to add the extender without opening the camera up to dust and moisture is also very important when working in less than ideal conditions.

Granted there may be circumstances in which the extra speed of a 300/2.8 lens or the extra reach of an 800/5.6 lens might be required, but for most photographers those situations are much less common than the need to optimally frame a shot or follow action with subjects changing in size as they move towards or away from the camera position.

The only negative comments I can make about the EF 200-400/4L IS USM Extender are that it’s very expensive and it’s neither small nor light, though there are certainly more expensive, heavier, and longer lenses in Canon’s lineup (for example, the 600/4L II IS USM). However, if I were a professional photographer making my living from my images and I was on safari in Africa with one big lens, the 200-400/4L IS USM is the lens I’d want with me!


Well, for $11,700 you could buy a canon_70-200/2.8Lis_II a canon_300/2.8L_II, a 1.4x III extender ($500), and a 2x III extender ($500) and still have $1700 in your pocket! Of course with 2 lenses and two extenders you’ve a lot more gear to haul around and you don’t have as much telephoto zoom capability, but you do have a faster 300mm lens and you do have 70-200mm (at f2.8) covered too. If you substituted the canon_300/4for the 300/2.8, you’d save another $4900, making the package just $5100, and if you substituted the canon_200for the 70-200/2.8 zoom, you’d end up with a total cost of only $3400. That’s $8300 less than the 200-400/4L IS USM Extender, but of course you now have 4 lenses to juggle and no ability to zoom.

Then there’s the tamron_150-600_5-6.3. It offers a wider focal length range, is much cheaper and much lighter, but it’s 2/3 stop slower and doesn’t have the same level of sophistication and optical performance as the Canon 200-400/4L IS USM Extender. However, for a typical amateur photographer, it is undoubtedly a much more cost-effective solution.

There’s also the sigma_120-300os for around $3000. Less telephoto reach, no built-in extender, but faster aperture and lower cost and weight. With a 1.4x attached, it becomes a 168-420/4 and with a 2x, it becomes a 240-600/5.6, which will still AF on all EOS DSLRs.

And of course there’s always the canon_100-400, which is about 15% of the cost of the 200-400/4L IS USM Extender, not to mention it’s much smaller and lighter. But it is slower and adding an extender takes it down to f8 where most Canon DSLRs won’t autofocus.

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