At 11 years old, is Canon’s EF 100-400mm f/4.5-5.6L IS II USM still a contender in today’s wildlife photography industry?
There’s a tendency in wildlife photography to want to own the fastest and longest lenses available to be successful. The obvious issue here is cost. Generally speaking, the faster the lens, the more expensive it is. This presents a demoralising barrier to entry for those on a limited budget.
At the time of writing this, Canon’s EF 100-400mm f/4.5-5.6L IS II USM is somehow 11 years old. I’m showing my age now; it only seems like yesterday when it made its big debut. Its release marked a significant upgrade from its predecessor, the mk1. The result was a lens with simply superb optical quality, at a more affordable price point. Given the advances in technology, notably the release of mirrorless camera systems, just how good is the Canon EF 100-400mm f/4.5-5.6L IS II USM today?
Canon EF 100-400mm f/4.5-5.6L IS II USM Specifications
Canon’s EF 100-400mm f/4.5-5.6L IS II USM was released back in December 2014. Its release disrupted the marketplace with the lens quickly gaining recognition for its simply superb optical upgrades compared to the previous generation.
The Canon EF 100-400mm f/4.5-5.6L IS II USM features a 77mm thread size and weighs 1,640g with the tripod collar mount. Not a lightweight lens, but handheld, it is definitely manageable. The lens’s optical design offers a superior upgrade to the Mark 1, with 21 elements in 16 groups. Its 9-bladed diaphragm also helps to create smooth, pleasing background bokeh. Fluorite and super ultra-low dispersion elements help to minimise the presence of artefacts and distortion. Additionally, a fluorine coating helps prevent dust and debris from sticking to the lens elements.
The Canon EF 100-400mm f/4.5-5.6L IS II USM offers customisable lens stabilisation with three modes, which provide up to 4 stops of stabilisation. The minimum focus distance is noticeably closer at a respectable 0.98m. Being an L-series lens, the Canon EF 100-400mm f/4.5-5.6L IS II USM inherits Canon’s outstanding weather sealing, making it resistant to dust and moisture.
On paper, the Canon EF 100-400mm f/4.5-5.6L IS II USM is a lens packed with features that make it a prime choice for wildlife photography. But do these features stack up in today’s industry?
Price and availability
The Canon EF 100-400mm f/4.5-5.6L IS II USM is still widely available as new from all reputable photography outlets. A brand new copy of this lens will cost around £2,500. The fact that this lens has maintained its price point for so long is a testament to its exceptional capability. However, the benefit of a lens having been established for over a decade is the impact on the second-hand market.
Pristine examples of this lens can be found second-hand for a fraction of the price, making it a steal for those with a fixed budget. Take Wex Photo Video, for example, a trustworthy outlet for used photographic equipment. An “excellent” copy of the lens can be found for £1049, described as light use and very light dust throughout the optics, which will not affect image quality in any way. Similarly, “good” condition copies can be obtained for around £800; however, expect signs of use and heavier dust throughout the optics.
Suitability for Wildlife Photography
Pairing with a Canon mirrorless camera body
The Canon EF 100-400mm f/4.5-5.6L IS II USM can be used with a mirrorless camera body via an EF-EOS R adapter. This combination breathes fresh life into an already exceptional lens. If you use the lens on a DSLR camera, you will not be disappointed. If you use the lens with a mirrorless camera, you will be blown away. Advanced features packed into mirrorless cameras, such as intelligent AI subject tracking and improved dynamic range, allow you to extract every ounce of performance from the lens. Tracking subjects has never been easier, allowing you to focus on capturing the perfect moment.
Focal range
Regarding focal length, a 100-400mm lens is a flexible starting point for most scenarios you will encounter as a wildlife photographer. Sure, you aren’t going to get frame-filling compositions of dramatically smaller subjects, not without some clever fieldcraft. However, for most subjects such as owls, foxes, deer, and waterfowl, you’ll be fine, especially with the option of cropping in post-processing. 100-400mm also becomes more usable when paired with a stacked crop sensor camera. The effective focal range in this case becomes 160-640mm (1.6x).
Coupled with a 1.4x extender, you can extend the focal length to 140mm-560mm, offering a substantial amount of extra reach. When paired with a Canon crop sensor camera (mirrorless or DSLR), the focal range is further extended to a staggering 224-896mm. Unfortunately, when paired with a crop sensor or full-frame camera, the use of an extender comes with a cost – a one-stop loss of light. We’ll cover more about the use of extenders later on in this post.
Here’s a photograph I captured at 400mm using the Canon EF 100-400mm f/4.5-5.6L IS II USM. Kingfishers are iconic small birds. By understanding their behaviour and utilising fieldcraft skills, you can get close enough to them to capture dream photographs. This is a fine example of the exceptional optical quality of the Canon EF 100-400mm f/4.5-5.6L IS II USM. The lens has delivered a pin-sharp photograph with a pleasing complementary background blur. To date, this is one of my favourite photographs captured with this lens.
Maximum aperture and low light performance
Aperture is an important element of the exposure triangle. An aperture of f/5.6 is one stop of light slower than a lens with a maximum aperture of f/4 and two stops slower than an f/2.8 lens. But what does this mean? Generally speaking, the lower the maximum aperture, the more light the lens will gather, making them desirable options for low-light photography.
In terms of aperture, a maximum aperture of f/5.6 at 400mm is a very usable aperture – even in fairly low light. I often use the EF 100-400mm II during the blue hour, one of my favourite times of day for photography. With a few technical tricks, the lens delivers mindblowing results. But don’t just take my word for it, have a look at a few sample images taken before sunrise and after sunset. In some situations, you may need to drastically increase your camera’s ISO to achieve a suitable shutter speed. However, with a little noise reduction in post-processing, you will still obtain very usable photographs.
Don’t get me wrong, the extra stops gained from having a faster f/4 or f/2.8 lens would be very much welcome, but the gains come at a cost, and a modest one at that!
This stunning barn owl was captured locally around 10 minutes after sunset, a time synonymous with low light. By timing your captures to coincide with reduced subject movement, you can increase your chances of capturing sharp photographs, even when the light begins to fade.
Utilising a slow shutter speed panning technique, I was able to capture a lovely example of a small group of migratory greylags and a pink-footed goose. This photograph was captured 20 minutes before sunrise, during the Blue Hour. Even under low-light conditions, with the correct technique, the Canon EF 100-400mm f/4.5-5.6L IS II USM is a capable lens.
Image Stabilisation
One huge benefit of the Canon EF 100-400mm f/4.5-5.6L IS II USM is its finely tuned image stabilisation. The image stabiliser has three customised options providing up to four stops of stabilisation. This means that you can capture sharp handheld photographs at dramatically slower shutter speeds. This is a real treat when it comes to photographing static subjects in tricky low-light environments.
Take, for example, this tawny owl capture. If you’ve ever wandered through a summer woodland, you’ll know how dark it is underneath the canopy. Without pushing your ISO setting to the absolute limit, obtaining a meaningful shutter speed can prove an almost impossible task. Thanks to image stabilisation (mode 1) and an amazingly cooperative model, I was able to capture the beauty of this female tawny handheld at 1/80th of a second at 400mm. Achieving this handheld without image stabilisation would have been a real test requiring a large amount of luck.
It’s worth bearing in mind that using image stabilisation for extended periods of time can drain your camera’s battery fairly quickly. This is especially true when operating a mirrorless camera. To offset this, you can either be more frugal with image stabilisation, using it only when absolutely necessary. Or, by carrying additional camera batteries.
Pairing the Canon EF 100-400mm f/4.5-5.6L IS II USM with a Canon EF 1.4x III Extender
Pairing the Canon EF 100-400mm f/4.5-5.6L IS II USM with a Canon EF 1.4x III extender will provide an extended focal length of 140-560mm when used with a full-frame sensor. The cost of this increase in focal length is a one-stop loss of light. This means that the lens operates with a new aperture range of f/6.3 – f/8. Make no mistake, this does make the combination much more difficult to use in low-light conditions. However, with careful consideration of available light, the combination is capable of delivering truly spectacular results.
That said, the Canon EF 100-400mm f/4.5-5.6L IS II USM paired with the EF 1.4x III extender doesn’t operate flawlessly. Subject tracking does become noticeably slower, and you’ll sometimes miss focus on subjects moving rapidly towards you. However, the combination enables you to capture photographs that might not have been previously possible. Being able to capture your subjects from a greater distance provides them with the space they need so that they don’t feel threatened. I regularly use the Canon EF 100-400mm f/4.5-5.6L IS II USM combined with the 1.4x extender, and more often than not, the results blow me away.
Sample photographs using the EF 100-400mm II paired with the EF 1.4x III extender
Below are some sample photographs featuring a barn owl I have become very close to.
Barn owls, like all owls, possess exceptional hearing and sight. If you make a noise, make no mistake, they will hear you at a great distance. With this in mind, it’s important to be as quiet as possible and maintain a respectful distance. This is achievable thanks to the combination of the Canon EF 100-400mm f/4.5-5.6L IS II USM and the EF 1.4x III extender. I have enjoyed countless hours observing this beautiful barn owl quartering and hunting on its personal hunting ground.
The detail resolved by the lens and extender combination is mind-blowing. These photographs (above and below) remain some of my favourites captured to date, all thanks to the extra reach provided by the 1.4x extender.
A further example below, captured at 560mm and heavily cropped, features an iconic short-eared owl.
One final photograph captured with the Canon EF 100-400mm f/4.5-5.6L IS II USM and Canon EF 1.4x III extender. This photograph was the result of patience and enduring extreme cold. After coming across a burrow in a local woodland, I decided to lie down in the snow and see if the owner would show up. Lo and behold, after almost an hour of waiting, a beautiful Wood Mouse popped up. I managed to capture this posture as it yawned, giving it a shocked expression. A truly magical moment made possible thanks to the additional reach provided by the extender.
Should you use an extender with the EF 100-400mm II?
In short, the answer to this question depends on the camera body you will be using. Modern-day mirrorless camera bodies featuring improved low-light capability and advanced AI tracking will handle the combination with minimal issues. Occasionally, you may struggle with autofocus tracking, especially with fast-moving subjects. In these situations, I find shooting in burst mode can help – your camera will regain focus, and you’ll reduce the chance of missing the opportunity with a high burst mode.
That said, pairing the combination with an older-generation Canon DSLR camera may not be a suitable option. It’s worth bearing in mind the extra stop of light lost and the reduced autofocus accuracy and tracking. If you have an older-generation DSLR that struggles with low light, you may be better off using the Canon EF 100-400mm f/4.5-5.6L IS II USM on its own and cropping your image in post-processing software. With some older DSLRs, you may even lose the ability to autofocus altogether. I would recommend checking compatibility via a credible source beforehand to avoid disappointment.
Alternative Options to the EF 100-400mm II for Wildlife Photography
Canon EF Lenses
- Canon EF 400mm f/5.6L USM
- Canon EF 500mm f/4L IS II USM
- Canon EF 600mm f/4L IS III USM
- Canon EF 400mm f/2.8L IS III USM
- Canon EF 400mm f/2.8L IS II USM
- Sigma 150-600mm f/5-6.3 DG OS Sport & Contemporary
Canon RF Lenses
- Canon RF 100-500mm f/4.5-7.1L IS USM
- Canon RF 200-800mm f/6.3-9 IS USM
- Canon RF 400mm f/2.8L IS USM
- Canon RF 600mm f/4L IS USM
Closing Comments on the Canon EF 100-400mm f/4.5-5.6L IS II USM
Over the past couple of years, the Canon EF 100-400mm f/4.5-5.6L IS II USM has been an absolute pleasure to use. It is a flexible lens that delivers extraordinary fast focusing and exceptional image quality. The lens is on the heavier side, but only because of its rugged build quality. Being a flagship L-series lens, it excels in environments where many other lenses would fail.
There are some scenarios where 400mm may not seem like enough reach. This is where fieldcraft comes into play. I think it’s easy to fall into the trap of wanting longer-reaching lenses to get closer to subjects. Ultimately, if you buy for this reason, you will never be happy. By becoming familiar with your subjects and understanding their behaviour, you can better position yourself to make the most of the focal length you have.
In situations with extremely low levels of light, clever use of technique can offset slower shutter speeds. Consider slow shutter speed panning, a phenomenal camera technique for illustrating subject movement whilst keeping the important elements sharp (eyes and body). Also, watch your subject closely and wait for moments where movement is reduced. Moments such as these offer perfect opportunities to capture sharp images at slower shutter speeds.
Paired with modern mirrorless cameras via an EF-RF adapter, the Canon EF 100-400mm f/4.5-5.6L IS II USM continues to shine. Image quality is on par with the newly released Canon RF 100-500mm f4.5-7.1L IS USM, and it benefits from almost one stop of extra light. The advanced AI tracking capabilities of modern Canon mirrorless systems allow the Canon EF 100-400mm f/4.5-5.6L IS II USM to flourish. Subject eye tracking is fast and accurate, even in complex environments.
Recommendation
If you’re looking for a flexible camera lens perfect for wildlife photography that doesn’t come with the high-end prime lens price tag, you truly can’t go wrong. The Canon EF 100-400mm f/4.5-5.6L IS II USM still packs a punch even with the release of modern RF lenses. This lens has well and truly stood the test of time and will continue to shine for many years to come.
If, like me, you want to save money and buy used, there are some phenomenal deals to be had. Shopping with reputable outlets such as Wex Photo Video will provide peace of mind knowing you’re buying a fully inspected and guaranteed lens.
Hopefully, this review has provided valuable insights into the performance of the Canon EF 100-400mm f/4.5-5.6L IS II USM in 2026. Yes, the lens is 11 years old, and modern-day alternatives are available. However, unless you’re looking at a high-end prime lens, you will be hard-pressed to find a more capable lens for its price point. As we approach that magical time of year for wildlife photography, I know that I can trust my Canon EF 100-400mm f/4.5-5.6L IS II USM to deliver. With that said, I’m looking forward to spring and capturing the magic of nature as it awakens from its slumber.