Review – Canon EF 70-300mm f/4-5.6L IS

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Review –  Canon EF 70-300mm f/4-5.6L IS
By: Dustin Abbott – WWW | Facebook | YouTube
Discuss the Canon EF 70-300mm f/4-5.6L IS

While we spend a lot of time around here grousing over the sensors in Canon camera bodies and lamenting the advances by Nikon and Sony, there is one area that we can all agree on – Canon is the platform for the best lenses in the world. Canon users are fortunate to have the best selection of telephoto lenses available for any camera system in both quality and quantity. The popular 70-200mm focal length is populated by five excellent L series lenses, including two f/4 variants and the 3 f/2.8 variants. The f/2.8 variants, in particular, are staples amongst event, sport, and portrait photographers.

But what about when more reach is needed, or when you are looking for a more compact option for travel that will retain great optical performance? The Canon EF 70-300mm f/4-5.6L IS USM may just be one of the best travel lenses that Canon has ever made. If you would like to see more/higher resolution photos, take a look here:

The announcement of this lens in 2010 raised a few eyebrows. The 70-300mm focal length is undeniably a great one, but Canon already had a number of lenses in that focal length, from bargain priced (and poorly performing) to a somewhat odd and expensive DO option. All were variable aperture starting at f/4 and moving to f/5.6 on the telephoto end. Why another one, and why such an expensive one? The fear of course is that Canon was going to put the optics of the 70-300mm IS USM in a better built body and charge a premium for it. That proved to be anything but the case, however, and when the real lens arrived in photographer’s hands it was quickly discovered that this was a premium lens.

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Unique Design
The 70-300L is a unique design amongst Canon’s lenses, although its influence can definitely be seen in the new 100-400L II. It is rather squat and the extending barrel is like a piston and has a relatively small filter size (67mm). It is not a light lens, but compared to most of Canon’s premium telephotos it is actually very light. It feels substantial in your hand, however, and its construction is outstanding. It is fully weather sealed and over my years of ownership I have used it in the deserts of the Middle East and the Southwestern USA, in the Caribbean, across North America (including the dead of winter here in Canada), and in Europe in all kinds of weather conditions. I have used it in dust, snow, and rain without any issue at all. The phrase “built like a tank” is often thrown around when discussing this lens. It was one of the first Canon lenses to get fluorine coatings that resist moisture and oil, making it a cinch to clean. Despite it being a regular in my travel rotation the lens still looks and operates like new. That makes me a very happy owner!

When it comes to travel the dimensions of the 70-300L pack extremely well. The 70-300L weighs 37.1 oz (1050 grams) while the 70-200L (f/2.8 II) weighs 52.6 oz (1490 grams), meaning that there is an almost 50% weight premium in the bare lens. A Canon 1.4x extender would add an additional 8oz (225 grams). Likewise, the length of the 70-300L is 143mm compared with 199mm for the 70-200L, while the extender adds another 27mm. This is a considerable amount of extra weight and bulk, particularly if you are walking for great distances. The 70-200 f/4L IS is lighter (almost 300 grams) or roughly equal with the extender, but it is several inches longer than the 70-300L, even more so with the extender attached. One of the strengths of the 70-300L is that while the barrel does extend during zooming (the 70-200 lenses are all internally zooming) it is the shortest length when not zoomed by several inches and is thus by far the easiest to store. It stands upright in my backpack like, say, a 135L, rather than having to lay flat and take up far more room. For travel I can put the Tamron 24-70VC and the Canon 70-300L in the main pouch of a medium sized sling bag with either lens attached to the camera body and still have the other pockets available for filters, batteries, and even a small wide aperture prime. It makes for a great travel kit that I can carry all day and hardly notice the weight. This two lens combination has become my go-to travel kit. It delivers far better image quality and versatility than a one lens solution.

Image Quality
But what matters most is the image quality. Canon already had a popular consumer grade 70-300mm lens (the EF 70-300mm f/4-5.6 IS) that is a decent lens but begins to really fall apart on the longer end along with a very compact Diffracted Optics (DO) variation that has not sold many copies due to the combination of high price and inferior image quality. The 70-300L improves on these in every way save price. The 70-300L has very, very impressive image quality. I frequently zoom in 100% on images and start smiling – I love that great sharpness. The 70-300L delivers throughout its focal range – even at the 300mm end sharpness, detail, and contrast remain strong.


That great resolution has very practical value when you consider that on a full frame body 300mm is still not particularly long. The outstanding resolution of the 70-300L means that I can crop significantly (even 100%) while retaining a sharp, usable image for most applications.

The lens is also a great option to pair with the better crop sensor bodies (7D or 7DII, 70D). The weight will balance better with the more pro grade bodies, although it will still work well on all of the Rebel (Kiss, xxxD) bodies. Mounted on a crop sensor body the focal length becomes an effective 112-480mm focal length, and with some of the modern crop sensor bodies this means that you can put a pretty good number of pixels on your subject. Image quality remains nice on a crop sensor body.

Autofocus and Use with Extenders
The autofocus (AF) system in the 70-300L is excellent. It is incredibly fast and virtually silent. I did tune the lens through AFMA lens adjustment on my bodies and this produced a noticeable improvement in focus accuracy, particularly at distance. With the lens “dialed in” it just doesn’t seem to miss. I would consider it one of my most accurately focusing lenses. In the bare lens I would consider the USM motor and its autofocus system one of the best I’ve used.

The lens’ design means that a Canon extender only mounts with the lens zoomed out to around 200mm and beyond due to a rear focus design that leaves little room for the protruding elements of Canon’s extenders. There is a risk of damaging the lens or extender if the lens was suddenly retracted, so I cannot recommend using a Canon extender on this lens. On top of that, the maximum aperture on the long end becomes an effective f/8 with a 1.4x extender, meaning that the lens will only autofocus with a few bodies anyway (7DII, 5D3, and 1Dx). That being said, I also own a Kenko 1.4x Teleplus Pro 300 (blue dot version) that works throughout the focal length and autofocuses without issue on my bodies (6D, 5DII, and 70D). In some situations there is moderately more hunting, but most of the time the AF is both fast and pretty accurate with this combination. Image quality takes a slight hit but remains very useable on either full frame or crop.

With Extender

One advantage is that the use of an extender does not change the minimum focus distance, meaning that you can increase your maximum magnification nicely. (The shot below is 420mm, f/11)

The Kenko disadvantage is that, unlike the Canon extenders, you cannot lock in a unique AFMA for the combination. That means that your standard AFMA for the bare lens might not be the right setting for the combo. I find my number of perfectly focused images does drop somewhat with the combination, although this is often only apparent at 100% magnification. When it is nailed, however, the images look great. The Kenko also has the benefit of being smaller in size than the Canon equivalent (which I also own), meaning that the system remains compact enough to fit in my sling bag. I find the image quality still quite excellent with this combination, even at 420mm, which certainly creates a nice option for the times when more reach is needed. (Note that the moose photo is @ ISO 12,800)


Very Stable
The 70-300L also employs one of Canon’s better IS systems. Unlike the IS in the 70-200 f/4L IS, the system is essentially silent. Unlike the Tamron 70-300VC (an excellent bargain in this focal range), the IS doesn’t jump in the viewfinder before locking in. Having a stable viewfinder image with a telephoto makes a huge difference when trying to compose your shot. The manufacturer’s claim of 4 stops of stabilization seems accurate here. I needed motion blur on the water for this particular shot, but didn’t have a tripod. I shot it at 1/10th of a second handheld and got a great looking result.

The IS has two different modes (denoted as 1 and 2 on the lens), one for normal use, the other for panning. I have found this system very effective when shooting in lower light conditions with relatively still subjects. Just remember that telephoto lenses really exaggerate motion blur, so if there is a risk of your subject moving, you need to get that shutter speed up. The effective and non-fussy system also means that you can pull the camera up and be immediately ready to capture action without waiting for the system to engage or to set up a tripod. On the subject of tripod, however, it should be noted that this is basically Canon’s most expensive telephoto lens to NOT include a tripod collar, nor does it come with a padded carrying case, just the useless bag that Canon supplies with many of its “L” lenses. This is a little obnoxious on a lens that costs this much. The tripod collar is available as an accessory, but the design of the lens makes it fairly unnecessary.

One area that really set this lens apart from cheaper variations (and even some more expensive lenses) is the quality of its bokeh (out of focus area). I used the Tamron 70-300 VC for several years, and it is, for the money, a superb lens. But one downside was its jittery, “nervous” bokeh in what is often called the “transition zone”. The focal length of these lenses mean that if you are very close to the subject the background will disappear altogether, but with telephoto lenses you are often quite a distance from your subject, which means the quality of the background beyond the subject becomes very important. In many cases the background will be closer to your subject than you are. When taking photos of animals, for example, this is a big deal, because you want some delineation (separation) between your subject and background and need the background rendered smoothly enough that it does not distract from the subject. The 70-300L really, really shines in this situation. Even difficult things like bare branches are rendered very smoothly, and the transition from focus to out of focus is excellent.  It has an eight curved blade aperture iris that retains very nicely round highlights even when stopped down.

As a result, my subjects usually have a very nice separation that adds dimensionality to an image. The lens has excellent color rendition and contrast, which further aids with getting a three dimensional effect on your subject.

The bokeh is surprisingly artful from the lens, with a very smooth transition to defocus that reminds me more of a quality prime lens than a variable aperture telephoto.

Where the Long Grass Blows

This adds up to a very versatile lens optically that I have even used in a pinch for portraits and weddings when traveling and not being able to carry a more purposeful portrait/event kit. The improved high ISO performance on bodies like the 6D means that there is far less a penalty for using higher ISOs due to a variable aperture lens, so, it works.


It is also a surprisingly effective landscape lens, delivering crisp results across the frame with excellent color and contrast. Telephoto lenses often add a great compression to elements in landscape images that pulls them closer to the viewer and makes them more visually appealing. 300mm gets a little long for this, but I have used the lens a lot between about 70-200mm for landscape shooting.


Some Plusses and Some Quirks
The 70-300L comes equipped with a focal length lock switch (only in the 70mm position) to prevent zoom creep. The relatively light front element means that zoom creep doesn’t really happen naturally, even after years of use, but I still use the lock if I am carrying the lens in a harness or on a Black Rapid strap where the lens will brush my body and eventually begin to zoom out. I also find it necessary to employ the lock when storing the lens, because if it is standing upright in my bag I will pick it up by the lens hood and the lens will zoom out before coming out if it is not locked.

Speaking of that lens hood: it is definitely a step up from the 70-200mm f/4 lens hoods (I have owned two copies of each variant) for a few reasons. First, it has a nice contour to it that adds a bit of style, but, more importantly, it has an improved matte finish similar to the finish on the 100L Macro lens and other newer Canon lenses. The finish on the earlier L series lens hoods was absolutely notorious for marking even when using caution. The new finish has proven highly resistant to scratching and marking. The finish on this lens is a little whiter than the older “great whites” of Canon’s line.

Another area deserves comment, and that is the issue of “focus breathing”. The 70-300L has a floating focusing system that is designed to minimize aberrations at close focusing distances. In this, it is effective. Image quality near minimum focus range is very good. The price that is paid for this system is in the form of “focus breathing”, which means that while the lens is 300mm at infinity, the focal length at minimum focus range behaves more like, say, a 200mm lens. Its maximum magnification (.21x) is only equal to the 70-200mm range lenses, and isn’t as good as most other 70-300mm lenses. I found this a mild annoyance at first, but the truth of the matter is that it doesn’t really have much significance in the field. The maximum magnification here is still quite useful, and the working distance is (of course) excellent at 300mm. The trade-off works out in the end, for while your subject may fill a bit less of the viewfinder/frame, it will be rendered a little more sharply. A mild crop can achieve a tighter framing, as will the use of extension tubes (near 100% crop here).

100 percent crop

Last Words
The combination of all of these things makes this a lens that I just can’t quit using. It is a great wildlife lens despite its variable aperture nature and only being 300mm. I’ve gotten a ton of wildlife shots with the lens that I’m proud of, and its compact size makes it an easy lens to bring along.


The great resolution means that I can crop extensively and still get a final image that is share worthy, like this shot of a lion that has been cropped nearly 100%.

I’ve considered selling this lens on occasion to get more exotic ones over the years, but it keeps winning me over with the combination of its attributes. Even now I am weighing its merits against the new 100-400L II, and haven’t fully made up my mind. The 100-400L II is an amazing lens and adds a bit more versatility as a wildlife lens, but isn’t as portable for travel. Decisions, decisions.

In conclusion, the truth of the matter is that I really, really love this lens. It has a few limitations, sure, but also has a great combination of killer optics and a great focal length in a sturdy and fairly compact body. It is a fabulous travel lens and a credible wildlife option. It even does a great job as a portrait or event lens when you don’t have a more natural option. I love it as a landscape lens as well. It isn’t cheap, but this is a pro grade lens that produces pro grade results. It hasn’t enjoyed the sales success of the 70-200 variants, but it is an extremely worthy lens that will hit the sweet spot for many photographers. The price has drifted down a bit to a more palatable $1349, too. If size and weight are a premium for you, this is one of the best choices you can make.

All Things Bright and Beautiful

Purchase Options:


  • Pro grade build quality
  • Compact size
  • Excellent optical performance
  • Small filter size (67mm)
  • Effective IS system
  • Very fast, very accurate USM focus
  • Surprisingly great bokeh
  • Versatile focal length
  • Excellent wide open sharpness at all focal lengths
  • Excellent minimum focus performance


  • No tripod collar or padded case
  • Some focus breathing near minimum focus
  • Doesn’t play well with Canon extenders
  • Variable aperture
  • Somewhat pricey