Review Canon Extender EF 2x III

Les McLean

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Maker/Provider: Canon

Product: Extender EF 2x III

Price: Around £400

Overall Rating: 8/10

Overall Summary:

An effective way of doubling the focal length of a compatible lens, with the penalty of reducing the maximum aperture by 2 stops.

Detailed Review

Like all my reviews, they are very much a personal thing, influenced by where you are coming from , what your needs are, and where you want to go with the particular bit of kit you are reviewing. So this review reflects my thoughts on what is important for me in this particular model, which I’m sure will be different from others’ experience.

I won’t be detailing all the bells and buzzers of the lens, all the technical information can be found at Canon's website here:

Canon 2.0TC III

As mentioned, the 2.0TC effectively doubles the focal length of a compatible lens, with a 2 stop hit, so a 200mm F2.8 becomes an effective 400mm F5.6 lens.

The two lenses I used for this review were the 200mm F2.8L and 300mm F2.8 L.

In using the lens my initial reaction was to be be pleasantly surprised to how good the image quality was using the extender both on the 200mm and 300mm lens, it's often been reported that using a 2.0 extender you take a significant image quality hit, perhaps so, but all I could see were eminently usable images, using both Canon 1DS III & 7 D bodies.

The second surprise was that the images at F5.6 were as good as images stopped down to f7.1/f8. Again it's perceived wisdom that by stopping down using a 2.0 converter improves image quality. I carried out a range of tests, obsessively pixel peeping, viewed on a calibrated 30 inch monitor, but I honestly could not see any difference in quality across aperture settings.

Here is an example from out in the field, taken with 300F2.8 +2.0TC on a Canon 1Ds MKIII, across different apertures.



I have included individual 1500 pixel image samples of the above with exif info intact

http://lesmclean.co.uk/2TC/600_f5%2C6_l.jpg
http://lesmclean.co.uk/2TC/600_f6,3_l.jpg
http://lesmclean.co.uk/2TC/600_f7,1_l.jpg
http://lesmclean.co.uk/2TC/600_f8,0_l.jpg

Below is a 100% crop from the left ear, at f5.6 & f8



A second test was to compare images taken with a 2.0 converter in place against the same image without, again taken with a 300 F2.8 on a 1ds MKIII




I then took a 100% crop (image with the TC) and a 200%crop (without TC)



I could see very little quality difference between the images at similar sizes, obviously using the extender gives you some wiggle room, even on a large file size of a 1Ds III , by effectively cropping an image without an extender to similar dimensions as an image using an extender , image deterioration becomes apparent.



The most obvious weakness of the lens for me is in focus and focus tracking, Canon report that there is a 75% reduction in AF drive speed when using the 2.0 TC, while my head understands this, typically my heart challenges this, rationalising that the maker's figures err on the side of caution etc, unfortunately, my head was right, and so was Canon, autofocus and autofocus tracking is significantly reduced.

As an example of this, for anyone who is familiar with my 'Jumping Jack flash' images, where I try and capture my dog 'in flight' running towards me. With either a 200mm or 300mm lens on a 7D, in a burst of 14 images in good light, if you disregard the first and last two images I can almost guarantee 100% of the images will be in focus and sharp using AI servo.

If I use a 1.4 TC (MKII) with the above lenses, my hit rate of images in focus from the burst drops to 40-60%

The other day, with a 200mm +2.0 TC on a 7D, and in good light I tried capturing Jack running towards me, the first run I had no images in focus, the second run I had 1 out of 14 in focus so averaging a hit rate of about 5% disregarding first and last two images.




I also tried tracking birds in flight, if the birds were small and flying fast, or any size bird against a similar background (mallards against a tree line for example), then the autofocus struggles, and loses focus regularly even if it does lock on. Canon does suggest however, that if you use the MKIII extender with current MKII L lenses, then the microprocessor in the extender improves AF precision.

Where it does work well in obtaining focus, if the subject is stationary/moving slowly and good light, I found that focus would be gained quickly with very little hunting, this was both on 200/300 lens and 1DS III/7D bodies.

In Use

Although I have had the lens for a short period, I think I can guess the situations I would probably use the 2.0 TC.
For shooting birds, if I was shooting large birds (herons for example) stationary or in flight, then it would definitely have a place in my bag, similarly shooting cricket, where often you pre-focus your shots (e.g. on the wicket), but would probably not consider it for Rugby where the action is often fast, frequently in low light. I can't see me using it much in people shooting particularly where a narrow DOF is required.

Strengths

Well built, light and (relatively) inexpensive way to double the focal length of a compatible lens. Weather sealing, extra lenses (9/5 instead of 7/5) against the MKII model.

Weaknesses

Price, £400 (street price) is still a lot of money for a small bit of plastic and glass.

Conclusion

Every day when I take the dogs walking, I always sling a camera over my shoulder, and when walking along our local river, it's more than likely a 7D with a 200mm f2.8L lens with a 1.4TC (MKII), this combination covers most of the bases I need during the walk. I can't ever see me regularly using the 2.0 TC instead of the 1.4TC, I just would not have the confidence it would produce the goods as well as the 1.4 TC combination, for the reasons given above.
Nevertheless, for specific occasions, it would certainly find a place in my camera bag, I'm not for one minute suggesting the image quality is up there with Canon's big primes, but it is good, it is very good.
 
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Les McLean

Les McLean

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Sample images using the 2.0TC, all images without any processing/cropping except resize for web+USM

Larger images sizes provided.

1# 1Ds MKIII, 300F2.8L+2.0TC, 1/500sec @f7.1 ISO200



http://lesmclean.co.uk/2TC/1DSL7703l.jpg

2# 7D+200mm F2.8L+2.0TC, 1/800sec @f6.3 ISO200



http://lesmclean.co.uk/2TC/IMG_7613l.jpg

3# 7D+300mm F2.8L+2.0TC, 1/400sec @f8 ISO800



http://lesmclean.co.uk/2TC/IMG_7323l.jpg

4# 7D+200mm F2.8L+2.0TC, 1/320sec @f7.1 ISO200



http://lesmclean.co.uk/2TC/IMG_7535l.jpg

5# 7D+200mm F2.8L+2.0TC, 1/500sec @f6.3 ISO640



http://lesmclean.co.uk/2TC/IMG_7432l.jpg

6# 7D+200mm F2.8L+2.0TC, 1/320sec @f7.1 ISO400

 
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#3
Hi Les, When you refer to the comparrison with the 1.4tc, is this the MK2 or the Mk3?
Thank you very much for this unbiased review.
 
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Les McLean

Les McLean

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Hi Les, When you refer to the comparrison with the 1.4tc, is this the MK2 or the Mk3?
Thank you very much for this unbiased review.
Sorry, I should have made it clear , I've edited my original review to indicate the 1.4TC is a MKII model, many thanks for pointing this out (y)

To add a couple of images from today's cricket , both with Canon 7D, 300 F2.8L +2.0TC MKIII

1/1000sec @f5.6, ISO1000



1/1250sec @f5.6 ISO1000

 
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Les McLean

Les McLean

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#5
Following my review, a friend of mine from the forum contacted me, basically querying my views on the sluggish autofocus and autofocus tracking of the x2 extender, he uses the x2 with a 300f2.8L IS, shooting low level jets, and his hit rate far exceeds my 5%.

With any review you are bound to get differing, sometimes conflicting views, that's why I always begin my reviews by emphasizing that the review reflects my thoughts, it's a personal thing.

I know that folk won't be rushing out to buy a bit of kit just because Les McLean thinks it's the best thing since Pans People, or not purchase because I said it's the worst thing since HDR processing. But I do know, following my review of the 7D for example, it can influence folk, or possibly nudge them a bit quicker in the direction they were already taking?

It did get me thinking, have I been totally fair in my review, the tests I did on autofocus were limited, do I need to give it a better run out before giving my opinion, was my judgement sound?

I did notice when shooting the cricket that with a 300mm F2.8L lens+2.0TC, it tracked focus pretty well, but it was generally good light, nice high contrast subjects and I used the focus limiter (6.5m-infinity).

So I think I'll need to revisit this particular area and report back.
 
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#6
interesting reading. would be interested in the focusing too
I have a sigma setup on an older canon and, once stopped down, really quite like the 2x extender. Maybe some of the issues are hidden by the older 8MP sensor on my 40D but it's certainly a bonus and for general shooting AF isn't compromised too much. Sharpness improves considerable from side open (5.6) to 2 stops down peaking about f8-f11 I think.
 
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