There was a rumor so that the Canon extender 2x II would not work with a 28-300L lens. Well, after finding a lot of websites where people said, no, it won’t work, and no one really demonstrated how so, I decided to buy one, try it myself and post a few pictures.


Here’s a pic of the setup:

I’m glad the extender isn’t too heavy, because I can already barely hold the lens in place when shooting in unusual stances, for example when trying to get a few pics of the moon. Yeah, I know, tripod is the key word here, but it’s so overrated… 🙂


So, the bottom line is, it works, but:

  • As some folks pointed out, the autofocus won’t work. After some research, I understood that the extender reduces by 2 the amount of light you get. So, it doubles the effective f-stop, which means that on the 28-300L f3.5-5.6, you’ll get 5.6×2 ~ 11 at the max zoom end. And in order for the autofocus to function correctly, you need f8 at the max zoom end of the lens, so the 28-300 is no good in that regard. Obviously, I used mine in manual focus.
  • Also, the extender won’t fit the lens when retracted out at 28mm, because the optical elements are then protruding at the rear of the lens. You need to extend the lens to its zoom end before adding the Canon extender. I’m not well-enough documented to say if this happens with all L zooms or not. I would gladly receive other people’s observations on this matter.

In the end, that’s a neat accessory to add to your collection (with a tripod!). You can get a way cheaper one on eBay, for $150-250, than on Amazon where first prices used are around 300. New, it’s worth $350 and so is its little brother 1.4x. The new generation of Canon Extenders 2x mark III is incredibly expensive for what it is: 500$ and up. Canon really has its own way of getting money out of its relatively basic accessories.