The Mk III EF Extenders: Just how good are they?

Over the last few months, I’ve lost count of the number of times I’ve been asked about the quality of the new Mark III Extender versions and whether they were worth the upgrade. Indeed there seems to be a) a lot of scepticism out there and b) worry that you’ll need the new lenses due for release later this year to really make the most of them.

Certainly the new Extenders are more expensive than the older versions, but having used them, the price in my mind is justified. I’d heard from a few people that have used them they were impressed, but it was only recently I really got to try them out and see for myself just what they were like.

When looking at Extenders, the 1.4x has always been we received. There are, I am sure, many of you who have a 1.4x but have shunned the 2x. I know I did it. I had both but found I never really used the 2x because it didn’t suit my needs and it certainly didn’t match up to my expectations of image quality on the lenses I used it on. I didn’t keep it that long before selling it to…no doubt to help fund some other kit purchase!

On to the Mk III versions though. These have been released to a big fanfare that they are better than the old ones. Like most, I was a little unsure, especially concerning the EF2x MkIII. My bad experiences in the past had always made me wary of them. Just last week though, I was lucky enough to have some fledgling blue tits drop into my garden on their first trip out of the nest box in the neighbour’s garden. The feeder in my garden became a hotbed for the blue tit parents to shuttle food too the three little ones that had made it. Not only that, but they were tame and allowed me to get reasonably close as well.

It seemed like a great time to strap a 2x  Extender on the EF300mm f/2.8L IS USM lens (note, this is *NOT* the Mark II version!) and see how it performed.

Was it good? In a word, Yes! Below is the same image, firstly with no sharpening at all – even in RAW, the Picture Style was set to Neutral and sharpening set to 0. The second version is simply with a change in Picture Style to Landscape and the associated sharpening that brings, but nothing else. The image is lit with flash only (hardly any ambient light at all) – you can clearly see the reflection of the silver brolly in the catchlight of the eye, but there will be more on the lighting of this image in a future post. Simply click on the tabs to see the two images which are 100% crops of the eye area, so you can see every pixel captured.

As you can see from the image, despite the 2x Extender being fitted, the image quality is still so sharp as to be eminently usable. Before you ask, the camera is an EOS-1D Mark IV and the settings were as follows: ISO 640, 1/250sec, f8.0.

There is another major benefit to this setup as well, especially with small subjects like this. The current EF600mm f/4L IS USM lens has a closest focusing distance of 5.5m (the new Mk II version, EF600mm f/4L IS USM II has an improved close focusing distance of 4.5m but it’s not yet available) whereas the combination of EF300mm f2.8L IS USM with EF 2x MkIII Extender allowed me to focus on a subject (and this is roughly measured rather than Canon spec as I can’t find one listed anywhere) that is only 240cm away. Yep, 2.4m rather than 5.5m! For subjects like this, that makes a big difference in filling the frame.

So the IQ is good and it allows you to focus very close, how about the AF? Well, despite the low light, as evidenced by the exposure settings I was using, the combination focused quickly and accurately – fast enough, even with the subject only 3-4m away, to catch these twitchy birds hopping around on the bird table.

What’s the result of all of this? If you’ve historically stayed away from the 2x Extender, now may well be the time to think again. It will add more reach to your lenses and the IQ loss is small enough to be not worth bothering about. I’ll certainly be keeping one in the bag when I’m out shooting subjects where a bit of extra reach would be welcome.

If you’re thinking about the upgrade of 1.4x Extenders as well, I’ve not done enough shooting with the 1.4x to give a direct comparison in as much detail as I’d like, but I can say the shots I’ve done with it have been sharper than I’d expect with the older Mk II version. Whether the 1.4x is worth the upgrade price for you is going to be determined by how happy you are with your current 1.4x model. Personally I think it is, but it’s your choice.