I’ve been using this lens for a little less than a year now, which is just long enough that I’m comfortable writing about it.

Like my other lens reviews, I intend to focus more on the ergonomics of day-to-day use than on optical performance. This is a conceit I must make for lack of money or equipment—optical benches are just so stupidly expensive. I’m also uncomfortable just making it up, or at least pretending that what I say has any objective meaning. What’s tack sharp to someone else may be a mushy mess to me, and vice versa. If you want hard numbers, I suggest you do what I do and head over to DXO Mark’s page for this lens.

The 70-200mm focal range has been the “pro” grade mid- to short-telephoto lens space for as long as I can remember camera companies making pro-grade zoom lenses. These lenses sacrifice 100mm on the long telephoto end that their consumer grade 70-300mm cousins have to insure the image quality is pro level. In fact, it’s only been recently that advancements in optical design have allowed for comparative quality 70-300 lenses; even then, there are still compromises.

Which 70-200 is right for me?

Canon’s 70-200mm range is a venerable smorgasbord of choice. Canon has elected to produce 4 variations on the theme, varying in max aperture (either f/2.8 or f/4) and inclusion of image stabilization. Quite honestly, I think this was a brilliant move, as it’s placed high quality lenses from $700 to $2600 and leaving the photographer to choose the features they want based on their needs and budget.

The advantage here is that you can avoid paying premiums for features that may be unnecessary. Don’t need to shoot in low light? The f/4 models will save considerable weight and money. Is all your work in a studio with strobes? The f/2.8 version without IS will save big money over the IS version and still get you the fast aperture for smooth buttery backgrounds.

The Canon EF 70-200mm f/4L IS USM

Size, Build, and Handling

This brings us to the EF 70-200mm f/4L IS USM, unlike its f/2.8 brethren the f/4L IS tips the scales at only 1.7lbs. (760g) and is a mere 3 inches in diameter and 6.8 inches long. By comparison, the EF 70-200mm f/2.8L IS II USM weighs 3.2 lbs. (1490g) and is 3.5 inches in diameter and 7.8 inches long.

Standing next to Canon's EF 100-400mm f/4.5-5.6L IS USM, very similar in size to their 70-200mm f/2.8Ls.

The smaller size and weight means two things. First, the lens can bTe hand held longer and easier than the larger f/2.8s. Second, and more importantly, the lens will fit in the secondary lens compartments of more bags than the f/2.8 versions will.

When I was writing about Think Tank’s StreetWalker Pro backpack, I noted that 7 inches is about the ideal depth for a bag, as most primes under 200mm and small zooms will fit in that space. In my StreetWalker Pro, I can carry this lens in one of the side lens slots instead of having to give up the main compartment. As a result, I can pack 2 bodies and a 70-200/2.8 or 100-400 in the main compartment and this lens in the side compartment with room to spare.

Loaded up in a StreetWalker Pro, it's may not look like it, but the bag closes just fine and the 70-200 isn't crushed in the slightest.

The control’s follows Canon’s pro style design traits; the focus ring is at the front and the zoom ring to the rear. The both the zoom and focus rings are wide and rotate smoothly. Like most Canon lenses, focus can be set past infinity, which is something to watch out for when focusing manually. Additionally, like other full-time manual capable USM lenses, the focus ring will rotate indefinitely, without a little more resistance indicating that the lens elements have reached the ends of their movement.

The EF 70-200mm f/4L IS USM is an internal focus and internal zoom lens; its length never changes regardless of focus or zoom position. Moreover, because of that the filter-rings are essentially part of the outer lens barrel and don’t rotate, which is good for creative filters like polarizers and split ND filters.

Unfortunately, there is one negative to the front filter rings. At 67mm, they are 10mm smaller than the filter rings on Canon’s other pro lenses. If you’re like me, that means a 67mm to 77mm step-up ring is in order. I’d also consider ordering a rubber lens hood, like this one, since you won’t be able to use the Canon one while using a CPL either.

A side effect of this is that it’s easy for Canon to weather seal the lens, and in fact this is a dust and weather sealed lens. It’s not waterproof, only water resistant. Submersion is flat out, but rain isn’t a problem. Also, like most Canon lenses, a front filter is needed to complete the weather sealing.

There is a groove for an optional tripod mount. The most appropriate part is the Canon Tripod Mount A II (W); the W indicates that it’s white, as there’s a black version as well. Strictly speaking, the lens is small and light enough that it’s not necessary to use a tripod ring with it. Unfortunately, clearance between the tripod ring and a gripped body is minimal.

With the tripod ring attached in the normal position, there's not a lot of room for fingers on a vertical grip.

Like other L lenses, it comes with a Canon ET 74 lens hood in the box. The ET 74 hood is a simple circular hood not a petal hood like the f/2.8 versions use. The hood attaches via a plastic bayonet system. Though tight out of the box, my experience with other Canon lenses leads me to it to loosen up as the “nibs” wear down through use.

Additional external controls include an AF/MF, focus limiter, and stabilizer activation and mode switches. They are located between the focus and zoom rings for easy access. The switches are Canon’s flat design and are relatively stiff, so they shouldn’t change accidentally.

Canon claims the image stabilizer is good for 4-stops. In my experience, it does a very good job of reaching the advertised rating. Like Canon’s other non-super-telephoto stabilized lenses, the IS system isn’t smart enough to detect whether it’s on a tripod or not. For maximum image quality when shooting from a tripod, the IS system should be turned off manually. Finally the IS system has 2 modes, mode 1 and 2, which must be manually selected depending on need.

Mode 1 is best for static subjects, it compensates for shake in all directions. Mode 2 is the “panning mode”, where the system only compensates for movement in the axis perpendicular to the direction of the pan. Like all optical stabilization systems, there are hard limits to what it can actually deal with. For example, it won’t make tack sharp images from a moving vehicle on a bumpy road.

Optical Performance

The lens consists of 20 elements in 15 groups, including 1 Fluorite element and 2 Ultra-low dispersion elements. The combination of UD and Fluorite elements mean that CA is well controlled; I don’t see any worth talking about in my images. DXO Mark has measured the lens’s CA at 6 microns; you won’t see it if you’re not using a very high-density crop sensor (7D, 60D, T3i) even then it will be minimal.

The exotic elements also help keep distortion under control. I use the built in profiled distortion correction in Lightroom 3 and with some lenses you can really see a difference turning it on and off, not so much here. DXO Labs backs that experience up, measuring the distortion on average at less than 0.5%.

Resolution is superb too, the lens easily out resolves my workhorse 1D mark 3, as well as my 40D backup. This is easily one of the sharpest lenses I’ve owned or used. Though like any other subjective qualification of lens performance, you should take this with a grain of salt.

Mobile resolution chart, also test AF tracking performance, sometimes. (click for 1:1 crop)

The low distortion and chromatic aberration coupled with the lens’s resolving power, allows this lens to be effectively paired with Canon’s teleconverters. With a 1.4x teleconverter the lens becomes a 98-280mm f/5.6, with the 2x it becomes a 140-400mm f/8 lens.

Normally I’d avoid using a teleconverter with a zoom lens. They magnify the optical flaws in any given lens, and image quality decreases rapidly. A better teleconverter helps, but only to a point; on some lenses, especially zooms, the loss of image quality always outweighs any gain in reach. This lens is one of the exceptions. In my experience, it’s virtually impossible to tell that there was a teleconverter involved by looking at the images alone.

Though a 1.4x teleconverter reduces the aperture by a stop, to f/5.6, the EF 70-200mm f/4L IS USM will continue to focus on all Canon bodies. Moreover, AF performance doesn’t appear to be appreciably slower when paired with a TC. Even in low contrast environments, like the one show below, I was able to snap the bird into focus more than fast enough to get the shot.

Even with a Canon 1.4x II teleconverter, there's no noticeable degradation in image quality. (click or 1:1 crop)

Speaking of autofocus, the lens has a 2-position focus limiter. The options are the full range of 1.2m to infinity and the reduced range of 3.8m to infinity. Using the 3.8m setting cuts focus travel, and this acquisition time, dramatically. Additionally, in the 3.8m mode, most cameras shouldn’t need to hunt due to defocus anyway.

The minimum focus distance is 3.94 feet (1.2M) resulting in a maximum magnification of 0.21x. With the 1.4x TC magnification is increased to .31x; with the 2x TC, 0.5x. The table below shows the magnifications and working distances with various extension tubes.

This isn’t a macro lens by any stretch of the imagination, though it is possible to get close to 0.5x magnification a number of ways making it at least usable in that fashion in a pinch.

TL;DR Conclusions

In short, what I’m saying is this is a very good lens. It’s as sharp or sharper than the EF 70-200 f/2.8L IS USM, and on par with the superb EF 70-200mm f/2.8L IS II USM (the new one), all the while being considerably lighter and smaller than any other f/2.8 70-200. Compared to the consumer 70-300s, it’s far better lens optically, and it has the advantage of being weather sealed.

The only real alternative worth considering from Canon is their new 70-300mm f/4-5.6L. Image quality is near enough between the two that you’re not taking a major hit, though the 70-200 is a constant f/4 lens and doesn’t extend when zoomed.

The EF 28-135mm f/3.5-5.6 IS USM is a mid-range general purpose zoom lens designed for Canon’s full frame cameras, but is equally at home on Canon’s crop bodies. The EF 28-135mm f/3.5-5.6 IS USM trades speed, some image quality, and a fixed aperture for a greater zoom range than it’s L or lower end kit counterparts, but compensates for that to some degree with an in lens image stabilization system.

Build and Construction

Fit and finish is quite good for a mid-tier lens. The EF 28-135mm f/3.5-5.6 IS USM lens is mostly plastic, but doesn’t feel cheap or plastic-y. In fact, the lens has quite a bit of heft, even with the  plastic body, enough to warrant a metal lens mount. Unfortunately, that mount, like the rest of the lens, isn’t weather sealed.

The finish is a smooth un-textured matte black, not the “powered coated” textured finish found on many Canon lenses. That said, the finish doesn’t mar or scratch easily.

In fact, in my experience the EF 28-135mm f/3.5-5.6 IS USM is quite robust for its size and price. It’s most fragile component is the image stabilizer system, and even that can take quite a bit of punishment.

Like most low- and mid-range lenses, the zoom-ring is given “priority”; it’s wider and located at the front of the lens with the focus ring behind it. This is typically reversed on high-end lenses, where the zoom and focus rings are typically equal in size and focus ring tends to be the front most.

The EF 28-135 f/3.5-5.6 IS USM fully extended at 135mm. (click to enlarge)

The zoom-ring on the EF 28-135mm f/3.5-5.6 IS USM is wide (the rubber grip is 7/8^th inch, the whole part that turns is 1-3/8^th inch) and textured rubber. The zoom-ring turns smoothly, though there is slightly more resistance starting from the shortest focal length. The complete zoom range is covered by turning the ring 90°. There is no zoom lock and the zoom can, and usually does, creep. Creep however, seems dependent on the specific lens; some lenses have a very pronounced creep others won’t creep at all.

Like most lenses in the wide to telephoto (walk around) range, the EF 28-135mm f/3.5-5.6 IS USM extends when zooming. Likewise, it follows the standard zoom design where the lens increases in length as the focal length increases and the hood is mounted on the end of the inner most lens barrel. As a result, the lens hood is most effective at the shortest focal length setting and increasingly less effective as the focal length is increased.

The extending lens barrel is composed of 2 parts. Because of this, there is a slight “wobble” or give in the front element that’s not there in single barrel lenses. However, the wobble seems to tighten up longer focal lengths. Moreover, I’ve never seen image quality issues due to this.

Autofocus on the EF 28-135mm f/3.5-5.6 IS USM is powered by a ring-USM motor. As a result, autofocus is fast and silent and full time manual focus is available. Additionally, the lens is of an internal focus design, so the front element doesn’t rotate or extend when focusing.

Manual focusing is done with a ½-inch wide hard plastic ring located near the middle of the lens. The complete focus range from close-focus to infinity is covered in 135°, which isn’t bad for an autofocus lens. While the ring is hard and plastic-y, it turns smoothly and feels good for a focus ring on a lens in this price range.

The only switches on the lens are for the autofocus and image stabilization system. (click to enlarge)

A distance scale is provided, though like most modern distance scales, its utility is limited. The internal focus design means that the infinity focus point can vary over a range with temperature and focal length. Because of that, it’s possible to focus past infinity. Finally, the distance scale lacks the hyperfocal/depth of field marks typically found on manual focus lenses. On the up side, the distance scale does have IR focus marks for all listed focal lengths.

The lens’s controls are rounded out with the autofocus/manual focus switch and image stabilizer switch. Both are located on the left side of the lens just behind the focus ring and use Canon’s older non-flat switch design.

The front of the lens features 72mm filter threads for protective and creative effect filters. 72mm has become something of a rarity in Canon’s line up these days, with the vast majority of lenses being either 77mm or 58mm.

Rounding out the features, the EF 28-135mm f/3.5-5.6 IS USM has a bayonet mount for a lens hood. Canon’s recommended lens hood is the EW-78BII, and this provider proper shading on a 5D, 1Ds or film EOS body. Unfortunately, the petals on the EW-78BII aren’t cut flat at the ends, so the lens won’t stand upright when set on the lens hood.

Performance

Optically the EF 28-135mm f/3.5-5.6 IS USM consists of 16 elements in 12 groups. It also has an aspheric element to help combat field curvature and spherical aberrations.

Let’s be honest here, though, this isn’t an L lens and it doesn’t have L lens image quality. Quantitatively, objective tests show this lens has less resolution, more distortion, and higher CA than its L cousins do, though sometimes not by a whole lot. That said I’ve never had much of a complaint with this lens optically.

Auto focus is quite and fast, thanks to the USM motor and internal focusing design. Focusing from infinity to a closer subject takes about 1s. Most focus moves, especially in good light, are considerably faster.

While the EF 28-135mm f/3.5-5.6 IS USM is not as fast as the 24-70 f/2.8L, the image stabilizer gives some breathing room as long as your subject isn’t moving. However, this lens uses one of Canon’s earliest image stabilizers so performance doesn’t stack up that well against lenses that are more modern. My testing and experience puts the IS system at about a stop and a half, give or take. On a full frame body that would mean handheld shutter speeds in the 1/15^ths (w) to 1/80^ths (t) range. On a crop body, speeds are about a stop faster 1/50^ths (w) to 1/160^ths (t).

The image stabilizer on the EF 28-135mm f/3.5-5.6 IS USM has a bit of an odd behavior. When shooting in portrait/vertical orientation, the stabilizer makes a noticeable diagonal shift when it engages or disengages. I’ve seen this on every copy of this lens I’ve handed, which leads me to believe this is normal behavior.

In the Box

Like all of Canon’s non-L lenses, the box contains very little beyond the lens. In the case of the EF 28-135mm f/3.5-5.6 IS USM the box contains the lens, as Lens Dust Cap E (rear cap), a 72mm snap on lens cap, instruction sheet, and warranty card. No hood ($30 extra) or pouch is included.

Alternatives

Canon produces 2 other full frame lenses in this range the EF 24-70mm f/2.8L USM and the EF 24-105mm f/4L IS USM, though either of these lenses cost about twice as much as the EF 28-135mm f/3.5-5.6 IS USM.

Compared to either of the L lenses, the 28-135 IS trades aperture, image quality, and wide angle for more reach. Whether that makes a difference is far more subjective. Compared to the EF 24-70 f/2.8L USM the 28-135 IS has almost twice as much reach. Though compared to the EF 24-105 f/4L IS USM, it’s not that much. Below is a comparison of 70mm, 105mm and 135mm with the same subject distance.

On a crop body, the EF 28-135mm f/3.5-5.6 IS USM has roughly the same field of view as a 50 to 200mm lens would have on a full frame camera. This put’s in a rather interesting, if a bit anachronistic, position. If you don’t shoot wide angle a lot, it’s a rather nice normal to telephoto zoom, with the widest setting being equal to the normal field of view produced by a 50mm lens on a film camera.

There’s not a lot of reason to go for the 28-135 IS USM on a crop body at this point. The EF-S 18-135mm f/3.5-5.6 IS covers the same range but goes wide enough to be a wide angle lens on a crop camera. It’s also lighter, though it doesn’t have the Ring-USM motor.

Verdict

Unfortunately the EF 28-135mm f/3.5-5.6 IS USM is a bit of an anachronism now. On a full frame, body the EF 24-105mm f/4L IS USM provides a constant aperture, better image quality, and weather sealing though at the cost of some of the telephoto reach and twice the cost.

On a crop body, the 28-135 is a normal to telephoto zoom, with an effective field of view equal to a 50-200mm lens. Here too the 28-135 has become an anachronism as well. The EF-S 55-250mm f/4-5.6 IS provides more reach and better pairing with the 18-55mm kit lens or EF-S 17-55mm f/2.8 IS USM. Alternatively, the EF-S 18-135mm f/3.5-5.6 USM covers all of the range of the 28-135 and adds wide-angle capabilities.

About the only setup that that makes sense is pairing the EF 28-135mm f/3.5-5.6 IS USM with the EF-S 10-22mm f/3.5-4.5 USM. This pairing provides the equivalent coverage from 16 to 200mm (in full frame terms) with a gap from 35 to 50mm in 2 lenses. Though neither is super-fast, they don’t take up a lot of bag space and provide a lot of flexibility.

One other thing that hurts the EF 28-135mm f/3.5-5.6 IS USM is that it’s a very popular starter/kit lens and that popularity coupled with its mid-tier build and optical quality, ultimately reduce the lens’s resale value. Used 28-135’s fetch maybe half of their new price.

One other thing to consider, if you’re using this lens on a crop body, the recommended hood doesn’t provide optimal shading (since it’s designed for a full frame sensor’s angle of view). Since the hood isn’t included by default, this means you can opt to buy an alternative if you wish. The alternative is the Canon EW-78C. This is the hood from the EF 35mm f/1.4L USM, and while it doesn’t provide ideal shading either, but it does provide better shading and is slightly better built as well.

In short: There are better choices out there now, but this is still a good lens if it fits your budget and needs.

Overview

Before digital, the 50mm lens was the standard. Moreover, it’s generally said the image produced is similar to what’s seen by the human eye. This made it a starting point from almost all photographers since it was easy to visualize the photograph before wasting film.

Digital has changed all of this; the introduction of crop sensors changes the lens’s field of view and increases the apparent focal length. Even then, the lens’s low cost still makes it a popular choice among many photographers especially those looking for a fast lens.

Canon’s EF 50mm f/1.8 II is the second generation of Canon’s EF-mount 50mm f/1.8 lenses, though its design inherits a legacy that dates to the late 1800s. Its f/1.8 aperture makes for good low light performance and shallow depth of field as well. Did I mention it’s also the cheapest lens in Canon’s catalog?

Build and Construction

Optically the EF 50mm f/1.8 II has 6 element 5 groups and appears to be a double Gauss or modified double Gauss design. The double Gauss lens design dates back to the late 1800’s and is simple, well understood, and very refined. This lens’s optical design starts from a solid foundation. Further, its slow speed, for 50mm primes at least, tends to yield better sharpness and less distortion.

It’s not only the optical design that makes the EF 50mm f/1.8 II inexpensive, Canon has cut out every possible feature from its construction.

The body and lens mount are plastic. I actually wouldn’t be surprised if the only things that were plastic in this lens were the glass elements and the electrical system. The build does make the lens incredibly light, 4.6oz (190g), though I’m not sure that makes much of a difference. That said, somewhat surprisingly the lens doesn’t feel nearly as flimsy as it sounds.

Unlike its predecessor, the mark II there is no distance scale. Though it’s nice to have distance scales, they are becoming increasingly useless on auto focus. Especially as features, like aperture depth of field marks, are omitted from designs.

The EF 50mm f/1.8 II also uses a cheaper micro-motor focus motor instead of a micro-USM or ring-USM focusing motor. The motor choice, however, doesn’t really affect autofocus speed, even with the lens’s overall linear extension design[i] there simply isn’t enough mass to be an issue. The micro-motor and gearbox is certainly louder than a ring-USM based motor but not really enough to be an issue or a distraction.

The lens lacks full-time autofocus, so when manually focusing the lens the autofocus system must be disengaging with AF/MF switch to MF. Failing to do so can damage the autofocus gearbox. Additionally the focus ring rotates when the lens focuses, so care is needed to avoid turning it or preventing it from turning when auto-focusing as well.

In an effort to further cut costs, the EF 50mm f/1.8 II doesn’t have a built in provision for a lens hood. However, the front element is recessed removing some of the need for a lens hood. That said, Canon does provide an optional snap -on lens hood in the form of the ES-62 kit. Another alternative is to mount a screw in lens hood on the filter threads.

Speaking of filter threads, the EF 50mm f/1.8 II’s has 52mm filter threads. However, because of the lens and hood design using them for anything other than a polarizer or special effect filters will increase the lens’s susceptibility to lens flare.

Performance

The EF 50mm f/1.8 II tests well in optical tests for its price. This is born out in real world use; the images tend to be acceptably sharp even when wide open though the corners are always a bit weak even stopped down. Vignetting is never completely removed on a full frame camera, even stopped down, showing about a 1/3^rd stop in the extreme corners. On a crop camera, there’s no appreciable vignetting at all, even wide open.

The biggest potential problem with this lens is the autofocus system. My experience is that it’s spotty at best, and performance is variable depending on many factors.

The copies I’ve handed have had problems repeatedly focusing on a consistent point, even in carefully controlled situations where there was nothing else to focus on and no camera motion. What will happen is the lens will front or back focus depending on the direction it’s focusing in. Even with AF micro adjustments, the problem persists, though you can typically get one direction or the other to be accurate, just not both.

What’s in the Box

What Canon ships with the lens is underwhelming at best. The retail box nets you the lens, a rear cap, a front cap, and a warranty card. As I said, there’s no lens hood shipped with the lens, that’s a $30 extra. Nor is there a pouch or case included.

Uses

On a full-frame digital or film camera the EF 50mm f/1.8 II is a normal lens, meaning it produces images that tend to have the same perspective as something view by the naked eye. It sees uses in journalism and anywhere where accurately portraying the environment is necessary. It’s also an acceptable lens for full body portraits.

On a Canon crop body the EF 50mm f/1.8 II becomes a short telephoto lens, with an angle of view similar to that of an 80mm lens on a full frame camera. This is at the short end of focal lengths commonly used for head and head and shoulder portraits. However, it also can make the lens difficult to work with for more general types of photography when in small rooms.

Additionally, the EF 50mm f/1.8 II is the cheapest fast lens Canon makes. This results in it being frequently recommended as a lowlight lens for beginner photographers to complement their 18-55mm kit lenses.

Verdict

Why the 50mm f/1.8 II remains popular is beyond me. Actually, not really, it’s cheap and fast, and most people fall over when they find out how expensive a good lens is. Even its half-stop faster better-built cousin, the EF 50mm f/1.4 USM, is more than 3 times as expensive.

The EF 50mm f/1.8 II is commonly recommended for most entry level photographers as a low light lens to pair with their Kit 18-55. This is something I don’t agree with; mostly due to the potential for autofocus issues and the tighter field of view.

When I bought my copy of this lens they were running for about $65, at that price, even with any issues, it’s hard not to pass on. At the time of this writing, the lens is retailing for $100 or more. At that price, I have a hard time recommending the lens at all.

While I’m not suggesting everybody needs $1000 L glass, there are better alternatives in the sub $500 range, unfortunately, just not in the $100 range.

One of this is Tamron’s well-regarded SP AF 17-50mm f/2.8 XR Di II. It offers virtually the same range as the kit 18-55 lenses with between a ½ and 2 stop fast aperture. Another alternative is Sigma’s 30mm f/1.4 EX DC HSM; it retains the normal field of view, adds a half stop faster aperture, and adds a ring-type ultrasonic motor for silent full time manual focusing. The final alternative is Canon’s own 50mm f/1.4 USM; virtually identical to the f/1.8 mark 2 but with a half-stop faster aperture and silent full-time manual with an Ultrasonic motor.

Personally, I don’t think skimping on lens quality is a good way to go. The inexpensive lenses don’t tend to hold up as well, more frequently have issues, and don’t retain the value in resale should you want to sell them.

Between the potential problems, and the availability of more flexible alternatives I say pass on Canon’s EF 50mm f/1.8 II.

In short: Save your pennies and get something better.

[i] Overall linear extension lenses shift all of lens elements to focus instead of just a few internal elements.

Canon offers two teleconverters that are compatible with their EOS series cameras, the Extender EF 1.4x II (discussed here) and the Extender EF 2x II. They have both undergone an optical redesign since their initial release, hence the II in the name.

Extender Basics

A tele-extender or teleconverter is a supplementary lens that is placed behind the main lens and acts as a magnifying glass, narrowing the captured angle of view and enlarging the subject. This is commonly described as increasing the lens’s focal length.

In the process of “extending” the focal length, the teleconverter reduces the lens’s effective aperture by a factor related to its multiplier. A 1.4x converter reduces the effective aperture by 1 stop; a 1.7x converter by 1.5 stops; and a 2x converter by 2 stops.

In addition to increasing the lens’s focal length, the converter also magnifies any aberrations that the lens may produce. This becomes more noticeable as the extender’s power is increased. The effects when using a 1.4x extender are often unnoticeable; however, a 2x extender can noticeably degrade even the sharpest lenses.

In addition to the optical affects, and the loss of a stop of effective aperture, the increase in effective focal length demands the use of good long lens technique to insure optimal results.

Canon Extender EF 1.4x II

The EF 1.4x II is a solidly built lens with an all metal body and metal lens mounts. In addition, it is fully weather sealed with a rubber gasket on the rear mount and the corresponding mating surface on the front mount.

The EF 1.4x II has a protruding front element, as seen in the photo above, this limits the number of lenses the EF 1.4x II is compatible with.

In general, the EF 1.4x II is compatible with most L and DO lenses that are 135mm or longer. This includes all four 70-200mm zooms. Lenses specifically not supported include the EF 135mm f/2.8 Softfocus and 70-300 f/4-5.6 DO. The Extender EF 1.4x II is not compatible with any EF-S lenses, or most lenses from 3rd party manufacturers.

Auto Focus

Canon’s cameras are designed to disable the auto focus system when the optical characteristics of the lens or lens and extender combination used with the camera exceed the sensor’s ability to properly focus.

For most Canon cameras, except those in the EOS-1 series, this means if the effective aperture exceeds f/5.6 auto focus will be disabled. Practically this means that for non EOS-1 bodies, the slowest lens that can be paired with the EF 1.4x II has a maximum aperture of f/4 or faster.

Canon EOS 1 series bodies will retain autofocus with the central point with lenses with an effective aperture of f/8. When using an EF 1.4x II, auto focus is operable with lenses that are f/5.6 or faster.

Workarounds for Auto Focus

It is possible to work around the aperture requirements though one of two mechanisms. There is the widely noted “tape trick” that involves taping over some contacts preventing the teleconverter from reporting itself to the lens and camera. In the name of science, I have tried this and frankly I found it to be totally useless. While it may work better with some lenses, it’s not something I would want to depend on working in a critical situation.

The second work around is for cameras that offer contrast detect AF in live view mode. These include the EOS 5D Mark 2, EOS 50D, and Rebel XSi, Rebel T1i. Contrast-detection auto focus isn’t subject to the minimum aperture requirements that phase-detection is, and therefor isn’t disabled and remains functional.

Stacking Teleconverters

The EF 1.4x II can be stacked with Canon’s EF 2x II extender as long as the 1.4x II is placed closest to the camera. In this configuration, the lens’s aperture will be reduced by 3 stops and its effective focal length increased 2.8 times. However, the Canon extenders weren’t designed with this operation in mind so only the front teleconverter reports its presence to the camera.

Performance

The performance of the Canon Extender EF 1.4x II is quite good, even when paired with lenses on the lower end of its supported range like the EF 100-400 f/4.5-5.6L IS USM and a high density sensor like that in the EOS 40D. When paired with the very high-end super-telephoto lenses like the EF 500 f/4L IS USM the difference in image quality is virtually unnoticeable.

As good as the Extender EF 1.4x II is the resulting image quality won’t match that of a longer lens. That said it’s not always desirable to have or carry a 600mm or 800mm lens or even a 400mm lens and this is where the EF 1.4x II comes into play. When packing light, and where long focal lengths aren’t going to be used the majority of the time, a 70-200 or 300 f/4 paired with the EF 1.4x II is quite capable of pulling of quite acceptable shots.

Handling

After some practice mounting and un-mounting the EF 1.4x II becomes very easy. The recommended procedure is to mount the convert to the lens then the converter-lens combination to the camera. This works especially well when the lens is mounted on a tripod and less so when everything is hand held.

There is one other consideration, due to the protruding front element the front cap for the EF 1.4x II is taller than a camera body cap, even though they are otherwise the same. This can be problematic if you drop all your caps into a single pocket in your pants or bag. If you do this, you might want to consider replacing your camera body caps with the same cap as the extender. This is part “Extender Cap E II” and they run about $7 a piece.

Conclusions

Like most photographic items, extenders fall in the “you get what you pay for” category. While the EF 1.4x II is a bit pricey, listing at about $310 at the time of this writing, the image quality over its cheaper competitors is very much worth it in my opinion.

As to whether you should get a teleconverter in the first place, that’s a more personal question. For $310 and 8 oz. you can add 50% more lens to your bag. For me, the increased flexibility is worth it for those times when I need the image more than I need a great image.