Lens review: Canon EF 100-400mm f/4.5-5.6L IS USM Zoom

Canon EF 100-400mm f/4.5-5.6L IS Zoom Lens

I had a chance to play with Canon’s affordable 100-400mm L series zoom last week. I rented it for a day from Penn Camera at Tyson’s Corner, mounted it on my 5D, and ran out to chase wildlife as soon as I got home from work. As the sun began to set, I took it up to the roof, set it on my tripod, and took photos of the horizon. In the morning, I snuck out onto the terrace at sunrise and got photos of that as well. All in all, I put the lens through its paces, shooting in daylight, dusk and dawn conditions, handheld and on a tripod. Even though I only used the lens for a day, albeit a pretty full one, I’m fairly comfortable with what I’m about to say.

Leap year for Mr. Chipmunk

Tree cover at sunset

The robin examines me

I liked it. The 100-400mm range is a versatile range, and the fact that you can get this L series lens at around $1,400 makes it a bargain. The lens isn’t as heavy as the 70-200mm L series zoom (which I played with today), and it’s fairly comfortable to hold for moderate amounts of time. It has a push-pull mechanism for extending the focal range, and that has its benefits and drawbacks. The benefit is that it does make it a bit easier to get through the large focal range a little faster. It’s also necessary in order to make the lens affordable. Push-pull lenses are cheaper to make than regular zooms, and require less glass as well, making them lighter.

Bethesda, as seen from the top of Grosvenor

Tuckerman Lane at sunset

➡ Updated 7/4/07: Erik Persson asked me two relevant questions this morning via private email. One is about how the autofocus handled, and the other was about whether autofocus is possible at all with an extender, or whether manual focus needs to be used. Autofocus was a bit slow, but that’s to be expected. This is a big zoom that can focus over a large distance. There is a focus limiter switch that decreases the focusing distance. You tell it to focus either from 1.8m to infinity or 6.5m to infinity. If you know you’re only going to shoot things farther away than 6.5m from you, then set the switch to that, and the autofocus will be a little faster. I’m not sure how to answer Eric’s second question. He suggests autofocus on EOS models up to the 5D is possible only up to f/5.6, and Mark 1D models can autofocus up to f/8.0. Not sure about that. I can only point you to this lens chart at Canon, which talks about the compatibility of the extenders with various lenses, and tells you what the expected aperture will be, and whether or not autofocus will be possible at all. I checked the specs for the 5D and 1Ds, and can’t find the upper f-stop limits for either models. Perhaps a call to Canon will clear this up, but it is the 4th of July today, and I doubt they’re open. Maybe one of you who has more information is willing to comment on this.

Beautiful swallow

Ugly one awaits

➡ Updated 7/6/07: Erik got back to me once more with a link to a review by The Digital Picture, where the AF to aperture specs are discussed. Furthermore, he provided a link to specs from Canon for the EOS 1v SLR (film camera) where the bit of information about being able to use AF with lenses that only open to f/8 is provided. So it looks like you’ll have to use manual focus if you stick extenders on the 100-400mm zoom. Thanks Erik! You know, you could just as well use the comments instead of sending me emails, but whatever works for you. 🙂

Moon rises over Grosvenor

Grosvenor rooflines

If you’ve been looking at the 400mm f/2.8L tele, which retails around $6,500, and you’re wondering why this lens is so inexpensive, you should know there is a reason for the price difference — but I doubt you needed me to tell you that. I stated the reasons in the paragraphs above, and they are: less glass, push-pull mechanism for the EF 100-400mm zoom lens. I haven’t tried out the 400mm tele myself yet, but I have a feeling it’s a great deal sharper and has more contrast than this lens.

Early morning contrails


I think you can already guess what my two complaints are: the details are a bit soft when the photos are viewed at 100%, and the push-pull mechanism creates a sort of vacuum between the camera and the innermost lens. Every time I extended or contracted the lens, air rushed in or out through the crevices. I’m sure things are isolated pretty well and dust doesn’t get sucked in, but it feels odd, and it makes it difficult to stop at say, 300mm. It’s certainly a lot easier to either pull the lens all the way out to 400mm or push it all the way back in to 100mm. You know how they say that zoom lenses are soft at either ends of the focal range? Well, it would have been nice to have some sort of limiter switch that could let me stay between 110-390mm, or something like that. With the push-pull mechanism, it was hard to get the focal length just below or above its limit in order to avoid softness.

Wood duck advances

EF 100-400mm lens, wide

Having said all this, let me reassure you that this lens is a bargain at its price. If you’ve had your eye on it, get it. Realize you won’t get the results you might get with a more expensive tele, but you won’t pay through the nose for it either. This lens will definitely shine on cropped sensors like those found in the 30D and Rebel, where the effective focal range will be 160-640mm. How else can you get in the 600mm focal range without spending a ton of money? What’s more, with extenders like the 1.4x or the 2x, you can get up to 800mm on a full sensor or up to 1260mm on a cropped sensor. That’s pretty amazing!

Heron at Grosvenor Lake

Afternoon traipse

There are a few other things to keep in mind though. The maximum aperture at 400 mm is f/5.6, and that means you’ll need pretty good light in order to shoot handheld with it. If you stick an extender on it, the effective aperture will get even smaller, so you’ll either need serious daylight or a tripod. But, as I’ve already said, you get amazing range with this lens, and it’s inexpensive for an L series zoom. If you’re willing to live with the few issues I’ve outlined, then get it.

Many lives


Buy the lens

Sun sets over Grosvenor


14 thoughts on “Lens review: Canon EF 100-400mm f/4.5-5.6L IS USM Zoom

  1. Pingback: Summer scenes from Grosvenor Park « Raoul Pop

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  4. Landon, I haven’t tried the 70-300mm lens, but I hear it’s pretty good. One difference that comes to mind right away (other than the focal length) is that the 100-400mm lens is L series, so it’s built tougher.

    For your needs, I’d say stick with the 70-300mm. Since you’ve got an XTi, the 100-400mm lens, with its heft, would really imbalance you. The XTi is much too light a body for this lens.

    If you do need the extra reach, try the 1.4x or 2x extenders from Canon, but check to make sure they’ll work with your lens first.

    As for the dust seeping in, it’s possible. The push/pull zoom mechanism does create a sort of vacuum in side the lens and sensor chamber, so it’ll tend to suck stuff in then blow it out as you adjust the focal length. This mechanism seems to me to be more prone to dust problems overtime than the regular zoom ring-based mechanisms. Then again, this is an L series, so I would hope Canon addressed that issue. Not having used the lens extensively, I can’t give you a definitive answer on this.


  5. Landon White says:

    For my xti I have an EF 70-300mm f/4-5.6 IS USM
    Telephoto Zoom Lens and wonder if the EF 100-400mm f/4.5-5.6L IS would be significantly better. I’m a beginner/intermediate user interested in wildlife photography so the extra reach sounds good to me. I also assume the glass is significantly better. But I have no guidance as to whether or not I can expect significantly better pictres.

    I’ve read concerns about dust seeping in in other reviews of this lens.



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  7. Pingback: ComeAcross » Review: Canon EF 70-200mm f/2.8L IS USM Zoom Lens

  8. Pingback: A Photo a Day (roughly) » Window to the past

  9. Pingback: ComeAcross » Choosing between Flickr, Zooomr and Picasa Web

  10. Pingback: Review: Canon EF 100-400mm F/4.5-5/6L IS USM Lens at Imaging Insider

  11. Cosmin, I’ll write a separate post about that. Yahoo Photos is merging with Flickr, so I believe you’ll have the option to export your photos to them, but there are some other things to consider, and I’ll talk about them in my blog post.


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  13. cosmin says:

    hey Raoul,
    Happy 4th of July!
    Would you be able to comment on the differences between Picassa, Flikr and Zoomr which I see you’re using?
    Apparently Yahoo is closing down the photos section and now I have to move some good gigs of pics 😉

    thx much,


  14. Hey Raoul,

    Thanks for publishing your findings!

    Shortcomings aside, this baby’s still on my short list unless some international magazine pays me a ridiculous sum of money in the near future so I can go for some fast primes 😉



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