Extension tubes are a useful accessory that allows you to shorten the minimum focus distance of a lens by moving it further away from your camera’s sensor. In other words, it allows you to get closer to your subject and often create macro-like images without the need for a dedicated macro lens. If you aren’t yet familiar with extension tubes, I would first encourage you to read my guide: The Ultimate Guide to Extension Tubes.
Having read the guide, or perhaps you already know all about the tubes already, you’ve obviously come to the conclusion that you’d like to buy some because they’re clearly very useful, and also a great value accessory to help you capture different images with existing lenses. Once you reach that conclusion, every Canon shooter is then faced with this next question: “Should I buy the official Canon extension tubes, or should I buy a cheaper third-party set? What is the difference?”.
It’s not possible to compare every single kind of third-party extension tube, but by far the most popular ones are those made by Kenko. In this post we’re going to compare the pair of Canon extension tubes, with the set of three Kenko extension tubes that cost about half as much money.
Canon sell a 12mm extension tube and a 25mm extension tube. Tubes can be stacked together create various combinations, and the thicker the stack of tubes, the closer the MFD moves towards the front element of the lens. Kenko don’t sell the tubes individually as Canon does, but instead sells them as a set of three tubes that have 12mm, 20mm and 36mm thicknesses. Again, you can stack these together in any combination to create new thicknesses.
The Canon EF12 II sells for about $80 and the Canon EF25 II sells for about $135 which gives you a combined price of $215. The set of three Kenko extension tubes sells for just $110, essentially half the price!! Given the fact that these tubes contain no optics in them at all, you can begin to understand why everyone considers this question when it comes time to make the purchase. Why should Canon air be more expensive than Kenko air?
Don’t like words? Here’s a video instead.
Canon or Kenko?
As you can see in the set of images below, the physical differences between the Canon and Kenko extension tubes are very small. If you pick them up blindly with the lens caps removed, it’s essentially impossible to tell them apart by weight alone, and both brands feel equally well made in all but one area. That one area where the Kenko tube feels quite different is the lens release lever. Externally the levers look very similar, but the Canon lens release lever is definitely far smoother. I never actually had any lens release problems with the Kenko ones, but the lever action felt creaky and stiff compared to the much smoother Canon version. In every other design respect on the tubes themselves, it has to be called a dead heat. I was genuinely impressed by how similar the Kenko tubes were to the Canon ones.
You may have noticed that I prefaced the statement in the previous paragraph by saying “with the lens caps removed”. This is because the caps are very different on the Kekno tubes as you can see in the image at the very top of the article. The Kenko caps are clearly much cheaper than the standard Canon ones and whilst they may just be dust caps for an empty tube, their poor quality feel did bug me to the point where I just put some spare Canon ones on them instead. Lens caps are cheap, and most people have a couple of spares lying around so it’s not a huge deal, but I do think it’s worth a mention. With the caps removed, the two products feel almost identical, but the poor quality caps actually lowered my overall impression of the Kenko ones at first because I initially examined the tubes with the caps on. The caps made the whole product feel more cheaply made at first touch.
I’m pointing this out so that if you decide to examine them both in a store to make your decision, make sure you take all the caps off them to level the playing field!
One thing that’s also worth a discussion is exactly how many extension tubes you really need? It’s nice that the Kenko ones come as a set of three, but there is a danger that the perceived usefulness of three different tubes may cloud the comparison somewhat. Personally I think that many people can get away with a single tube, or two at the most. In my time experimenting with these two sets, I thought the Canon combination of a 12mm and a 25mm was perfect. I never needed three tubes, and in fact I would almost certainly never use the Kenko 36mm tube if that was the set that I owned. With a 12mm and a 20mm (kenko) you can stack them to get a 32mm and that seemed to be large enough for most things. I do realize that some people will find a use for the larger one, or larger stacks that contain the 36mm one, but I don’t think this would be the majority of people.
In terms of autofocus speed, I couldn’t see any discernible difference between using the Canon or Kenko tubes. To be honest, most of the lenses I tested them on all seemed to slow down a little bit when focussing on things that were right on the edge of their MFD but it didn’t seem to be a Canon Vs. Kenko difference. Whenever I tired to do a blind AF speed test, I was always left unconvinced which tubes I was using. If there’s any difference, it doesn’t appear to have a noticeable effect in real world usage.
I have to say that I was very impressed with the Kenko tubes and it’s clear to me that they are a better buy than the Canon ones for the vast majority of people who are looking to get macro-like images from from smaller lenses. Having said that, I would, in fact do, own the Canon tubes. The reason is simple: I’m using these extension tubes on lenses that cost upwards of $10,000 when they are on my super telephoto lenses. If I think there’s even a 1% chance that the Canon ones might be a fraction stronger, or more roust than the Kenkos, I’m going to spend the extra $100 to buy the Canon ones. It’s just not worth taking any risk at all for such a fractionally small amount compared to the value of the lens, and potentially the value of the trip that I’m using the lens on. I mentioned that the lens release lever on the Kenko tube doesn’t feel as good as the Canon one, and that alone is enough for me to stick to the official ones over the third-party ones. The last thing I want is to find that in cold weather, the release mechanism fails and the locking pin jams into my super tele lens rendering it useless. Of course this could happen to the Canon ones as well, but having felt the mechanisms in both of them, I’m definitely less confident in the Kenko ones.
As I said, for most people I think the Kenko ones are going to be a better buy, though. If you are putting them on a short zoom lens, or a short prime lens like a 50mm, then the Kenko tubes will perform exactly as the Canon ones do. I don’t think you really need all three of the Kenko ones, so I do wish they sold them individually, which would allow you to buy just two of them and save even more money. I suspect that Kenko knows you don’t really need all three, and that’s exactly why they sell them to you in this way. Regardless, I was impressed with them, and I didn’t expect this to be my conclusion at all. I always knew the Canon ones would be right for me personally, but I didn’t expect the Kenko ones to be such a good copy of the Canon ones to warrant my recommendation to most people. I like it when I’m surprised! Even more so when it means it’s going to save you guys some money!