Review: Canon / Kenko Extenders


Update 28/07/2009
Before I begin…

After this article has been read over 400 times in the last few weeks I feel quite satisfied – but… No one left a comment. How in the world should I know if I could have done something a better and / or different way to further improve articles like that. I’m planning to release more of that, but without input it is really hard. So please, if you have ideas, suggestions or anything else, leave a comment!
Anyway, thanks for reading!


Recently I thought about getting a big lens for animal, bird or sports photography. My Canon EF 70-200 f/2.8 L IS USM is great, but it lacks of higher zoom range. I looked at different sites on quite a lot of reviews.  I was sure I wanted image stabilizer. The inner circle of lenses in the end were:

  • 1) Canon 300mm f/4 L IS USM
  • 2) Canon 300mm f/2.8 L IS USM
  • 3) Canon EF 100-400 mm f/4.5-5.6 L IS USM
  • 4) Sigma AF 80-400mm f/4.5-5.6 EX APO OS
  • 5) Sigma 150-500 mm f/5-6.3 DG OS APO HSM

The first one is rather affordable with around 1.150 €, the second is way out of my budget with 3.900€. 3rd cost about 1.400€, 4th and 5th you can get as cheap as 820€ and respectively 900€. But then I was thinking about carrying all that stuff along. Another clunky lens would not even fit in my backpack, and I just love my 70-200 2.8 too much to leave it at home. Therefore I looked a little deeper in Teleconverters / Extenders. I had one at home, the kenko, and the others I was quick to buy (and to return after the test).

The good: low costs (only about 300€ for per extender)

The bad: Loss in aperture compared to some lenses and loss of image quality (??? really??? That’s what I want to know!)

More after the break…



I heard a lot about image quality loss, espacially in sharpness of the 2.0x extenders. But I did not find any satisfacturing test and comparison. THere os one webpage thats rather dedicated on this topic: They compared resolution of the different tele converters here: (on a 5D Mark II). A comparison of  Kenko and Canon extenders can be found under and (seems like on Canon APS-C).

Additionally to these tests I wanted to know a little more about the influence of aperture. Therefore I created a stable (studio-like) setup with two flashes and a black background. I shot the following series of images (all @max zoom):

  • 70-200 w/o extender @200mm f/2.8, f/4, f/5.6, f/8, f/11 and f/22
  • KenkoTeleplus PRO 300 DG 1.4x  @280mm f/4, f/5.6, f/8, f/11 and f/22
  • Canon  EF 1.4x II @280mm f/4, f/5.6, f/8, f/11 and f/22
  • Canon EF 2.0x II  @400mm f/5.6, f/8, f/11 and f/22
  • Kenko Teleplus Pro 300 DG 1.4x & Canon 1.4x II @392mm f/8, f/11 and f/22
  • Kenko Teleplus Pro 300 DG 1.4x & Canon 2.0x II @560mm f/8, f/11 and f/22.
  • Canon 1.4x II & Canon 2.0x II @560mm f/8, f/11 and f/22

This was a little bit changed compared to my original plan but I dropped the test @ minimum zoom as well as some combinations because they were simply not possible mounting due to build. Therefore combinations were mounted “camera-1.4-2.0-lens”.

In this test will not give you a lot of numbers because I’m too less expirienced in that (anyone like to help? I send you all the images!). I’d rather give you the images and my opinion. Ten you can see what was my impression and can make up your mind as well.



Canon 5D Mark II on a tripod, horizontally aligned with the iPhone box on the glass table. All shots were taken with the Canon EF 70-200 f/2.8 L IS USM with IS turned off and a pol filter attached to minimize reflections. Cable release and mirror lock option was used to minimize vibrations. I focused manually on the “Safari”-text in live view @10x magnification to get best results. I tried to keep the focus area in center because there is the the best sharpness / resolution to be espected. I used a black backdrop, ambient light was the same all the time (night). Finally I put up two flashes (2x Nikon SB-26). I toggled flash power down (on both flashes) with lower apertures to get equal lighting following this scheme:

  • 1/1 @ f/22,
  • 1/4 @ f/11,
  • 1/8 @ f/8,
  • 1/16 @ f/5.6,
  • 1/32 @f/4.0 and
  • 1/64 for f/2.8.

I reviewed the images on my 1920×1200  HP monitor as well as on two dedicated imaging monitors with 5 Megapixels each to get a better side by side impression in full resolution.

So far so good. Stable environment, all set up. Let’s go on to the…


A)First see a comparison on zoom ratios

w/o teleconverter

200-1, ursprünglich hochgeladen von martin zeile photography

Kenko Telepuls Pro 300 1.4x

14k-1, ursprünglich hochgeladen von martin zeile photography

Canon 1.4x II

14c-1, ursprünglich hochgeladen von martin zeile photography

Canon 2.0x II

20c-1, ursprünglich hochgeladen von martin zeile photography

Kenko 1.4x & Canon 1.4x II

14k-14c-1, ursprünglich hochgeladen von martin zeile photography

Kenko 1.4x & Canon 2.0x II

14k-20c-1, ursprünglich hochgeladen von martin zeile photography

Canon 1.4x II & Canon 2.0x II

14c-20c-1, ursprünglich hochgeladen von martin zeile photography

B) Now full size crops from the RAW files at different f-stops – converted to jpeg, quality 100%

B.1) Sorted by applied converters
You can download full size pictures by followin to my flickr page and clicking on “all sizes”.

w/o teleconverter

70-200 w/o teleconverter, ursprünglich hochgeladen von martin zeile photography

Kenko Teleplus Pro 300 1.4x

Kenko Teleplus Pro 300 1.4x DG, ursprünglich hochgeladen von martin zeile photography

Canon 1.4x II

Canon EF 1.4x II, ursprünglich hochgeladen von martin zeile photography

Canon 2.0x II

Canon EF 2.0x II, ursprünglich hochgeladen von martin zeile photography

Kenko 1.4x & Canon 1.4 x II

Kenko Teleplus Pro 300 DG 1.4x plus Canon EF 1.4x II, ursprünglich hochgeladen von martin zeile photography

Kenko 1.4x & Canon 2.0x II

Kenko Teleplus Pro 300 DG 1.4x plus Canon EF 2.0x II, ursprünglich hochgeladen von martin zeile photography

Canon 1.4x II & Canon 2.0x II

Canon EF 1.4x II plus Canon EF 2.0x II, ursprünglich hochgeladen von martin zeile photography

B2) Sorted by f-stops (f/5.6 and f/8 only) – 1st without interpolation, 2nd interpolated to match sizes of all images

f/5.6 w/o interpolation

f5.6 comparison, ursprünglich hochgeladen von martin zeile photography

f/5.6 interpolated

f5.6 zoomed comparison, ursprünglich hochgeladen von martin zeile photography

f/8 w/o interpolation

f8 comparison, ursprünglich hochgeladen von martin zeile photography

f/8 interpolated

f8 zoomed comparison, ursprünglich hochgeladen von martin zeile photography


First to say I was quite surprised of the quality of the teleconverters. AS pointed out in, lost of resolution is more to the edges than in the center (on Canon 5D Mark II with Canon EF 70-200 f/4 L IS USM @max aperture).

In my opinion it is mandatory to have a high quality lens to start with. In the above mentioned test it was a the Canon EF 70-200 f/4 L IS USM which was stated to have a higher resolution tahn the f/2.8 version that I used. But according to some another articles I remember this is only true for APS-C sensors (get and click through the review list of both lenses to get more details. I don’t know the exact source but I’m 100% sure about it), on full frame sensors the f/2.8 version is sharper.

The Kenko and the Canon 1.4x teleconverters showed no significant difference in my test. I got the impression that the Kenko enlarged slightly more but this was neglectable. Sharpness was as far as I can say equal. In the above article, sharpness loss was:

Kenko 1.4x : center -122,  enlarged center -471, edges -671
Canon 1.4x : center -101,  enlarged center -489, edges -474
Canon 2.0x: center -494,  enlarged center -471, edges -646

Kenko loses a little more to the edges compared to the Canon 1.4x, the Canon 2.0x is quite homogenously but starts with more sharpness loss in the center, rest is comparable to the others. I neither saw any difference between the 1.4x’s, but limitation of my test is that I focused the object in the center only. I exspected more quality loss for the 2.0x but was really surprised by the good sharpness it delivers, though I did not really measure it, just looked at the images side by side and let my eye decide. There it is perhaps useful to mention that I as radiologist am used to compare images all day long therefore I state for myself that I am in some manner experienced in that stuff.

As you can see, a lowest aperture the images look a little blurred with and without converter, that’s a normal thing to experience even with high end lenses. Stopped down by one or better two f-stops, blur was gone and the impression of sharpness was equal throughout the whole tested range with the suspicion of a slight drop @ f/22.

If you compare all crops at  f/8 I think there is no real significant difference in overall sharpness. But considering the longer focal range you gain a lot more detail @ 400 mm and 560 mm compared to the base of 200mm. Even combinations of converters are really good, and two 1.4x’s are almost equal to one 2.0x.

This leads me to my…


The Canon EF 1.4x II has a little performance benefit to the edges, but in the center it is the some compared to the Kenko. It also matches the color of the grey L lenses which could be important to some of you. Build quality feels better but weight is higher with approx. 200 grams compared to approx. 130 g on the Kenko side.
The KenkoTeleplus PRO 300 DG 1.4x has the advantage that you can mount it on every lens, the Canon is restricted to some zoom lenses (I post details on that later). Weight and sharpness was discussed right above. The price tag is about 90 € less which can be the argument for you, espacially if you are using APS-C sensors where sharpness loss to the edges is not so important

Final conclusion:
To get the highest quality go for the Canon 1.4x II especially on full frame sensors. If price and using the extender on other than some selected Canon L-lenses matters more to you, the Kenko Teleplus Pro 300 DG 1.4x is the better choice

2.0x and combination of 1.4x and 2.0x vs. other lenses (as mentioned at the beginning)
In my opinion this extender is very good and has a solid build (and matches the color of my 70-200). Sharpness loss is well compensated by the gain of focal length. I definatly keep my Canon EF 2.0x II and I will combine it frequently with the Canon 1.4x because quality is better if you shoot @560 mm than @200mm and then crop it to the focus of interest. It does’nt really mater which converter you combine with the 2.0x. Both perform almost equally with a slight favor to the Canon 1.4x but considering the price tag the decision could go for a lot of you towards the Kenko 1.4x.

Final conclusions:
In my opinion the 2.0x teleconverter is a good alternative to the costs that would involve buying another longer lens. E.g. a Canon EF 100-400 costs 1400€, the 2.0x about 330€ which will give you a 140-400 mm lens with f/5.6 compared to f/4.5-5.6. Quality should be almost comparable and weight is much lower Additionally it gives you the opportunity to go down to 70 mm and f/2.8 in my example of the 70-200 f/2.8 with the disadvantage of mounting or unmounting the extender.
Prime lenses will  always be better but come with the restriction of only one focal length – and of course they come with a price. If money does not matter to you and you can carry a bunch of heavy lenses around – or just need exactly on focal length, go for them! AF will be better and sharpness will be flawless for sure. APerture will be really good as well – depending on your extra budget invested.
If you still do not own a good lens  like a Canon EF 70-200 f/2.8 or f/4 L (IS) USM or similar from another brand , the Canon EF 100-400 mm f/4.5-5.6 L IS USM, Sigma AF 80-400mm f/4.5-5.6 EX APO OS, Sigma 150-500 mm f/5-6.3 DG OS APO HSM can be options for you. All have image stabilization, I don’t know if there are big differences between Canon and Sigma, therfore see the reviews at the end of the article, perhaps they give you a hint.
Considering the low price of under 820€ (Sigma 150-500) and 900€ (Sigma 80-400) are  good and cheap options. I tried the 150-500 myself in a store and was quite pleased by its performance, sharpness- and AF-wise. The 80-400 has EX build (Canon L-like build) shorter focal length but higher aperture. To decide between both is more a matter of what you will put it to use for. I added some reviews at the end of the article to help you decide better. The Canon, as always. compared to the Sigma is more expensive with around 1400€. It has a solid build (L-quality) and same aperture as the Sigma 80-400 and no real difference in focal length. To decide wether to go for the cheaper Sigmas or the Canon is mainly on what you like to spend, in my opinion quality of the Canon is really good, but see reviews at the end of the article to help you decide better.
For myself, not only shooting wild-life and sports it is no good choice. I would miss the capability to shoot at f/2.8 for portrait photography and nearer fast moving objects. As well as the wider focal range down to 70 as a addition to my Canon EF 24-105 f/4 L IS USM. But this is rather personal and dependent on what you already own. Money-wise it is a quite higher investment of  approx. 2000 € (1470 € + 330 € + 300 €) compared to approx. 770 €.

My choice will be both Canon extenders and I will be happy to have either a 70-200 f/2.8, a98-280 mm f/4, a 140-400 mm f/5.6 or a 196-560 mm f/5.6* lens depending on what I’m shooting. I have to admit that with two extenders AF becomes a little sloppy / hunting for focus and does not work well for fast moving objects. But for now, until I earn too much money than I can spend and buying me a big prime I am quite happy with my choice!

I hope this helps you decide. For me it was very interesting to do it. If you have questions – or answers, suggestions or if I got something totally wrong (which I hope not) leave a comment or write me an email.

Thanks for reading and stay tuned to my blog.

Cheers, Martin

Appendix: Reviews

1) Canon EF 100-400 mm f/4.5-5.6 L IS USM–review

2) Sigma AF 80-400mm f/4.5-5.6 EX APO OS

3) Sigma 150-500 mm f/5-6.3 DG OS APO HSM

4) Extenders

in German:

*f/5.6 at least is what my camera lets me dial down to. I don’t yet know if it is true or just a bug in the software and it is really a f/8. I will find that out and add it to the article soon.


Update: October 2011

Traumflieger has new reviews of multipleextenders, also the new Canon III Extenders and various Kenko models. Check it out under:


17 responses to “Review: Canon / Kenko Extenders

  1. Your review is quite good but I do not believe that the subject you were shooting had enough detail to make a firm conclusion about the quality of the lens/teleconverter.

    The 70-200 f/4L IS is indeed an excellent lens. The reason some say it is better on the APS-C format than the f/2.8 version is that the APS-C format, in general, has more closely spaced pixels and higher linear resolution as a result. In order to remain sharp, the lens must produce an image with equal or greater in resolution as the sensor. This is becoming an issue on the latest full frame sensors due to increased pixel density. For example, the Canon EOS 1Ds Mark III and the 5D mark II have the same pixel density as an APS-C format 20D, 30D, or 350D. A full frame sensor with larger pixels will be more “forgiving” of faults in a less optically perfect lens than a sensor with smaller pixels.

    Still, both the f/2.8 and f/4 versions are excellent lenses. The f/4 version is slightly better but unless they are pixel peeping, nobody is going to notice the difference. Plus, the f/4 lens will never give you f/2.8 when you need it!

    All the best,

  2. Appreciate your hard work. Enthusiastic test.
    Searching on how the 135L + 1.4x TC combo would work, as well as with 200mm f/2.8 L.
    To me, the results with iPhone box are hard to see the details..
    wonder if you would try with different materials next time.

    • I think I will try some other target in the future. Perhaps not as detailed as this one but closse enough. I do not own the Kenko any more so it will come down to the two Canon Extenders anyway. Thanks for the feedback. There will be more in the future!

      Concerning your question: I think the combination of the 135 L and the 1.4x is no problem. The 1.4x is an excellent piece of glass, no real problems concerning unsharpness or something like that. Your lens is an L, so optically it is as well at least good if not top notch. From my humble experience and from others I can tell you that you only must worry about quality with a 2x Extender and not so good glass. I can recommend the 1.4x, either the Kenko or the Canon without any hesitation to anyone who want a longer focal length.

  3. I like your test. I have 135 F2 and 200 F2.8 and I am trying to make my bag lighter. If 135 with 1.4x will give a quality equivalent or better than 200 F2.8 then I’ll buy 1.4x in a heart beat and get rid of 200 F2.8 and get some other lens. Anyways appreciate your methodological testing

  4. Thank you. it would be great if you could explain how much -101 is in loss. Too me it is just a number. Judging by the pictures it seems to be nothing. Perhaps a pixel to pixel cropped comparison picture without extender side by side with a shot with extender would tell. Now it is hard to see when the crop is different.

  5. Well I asked a question between the Canon 1.4 IIExtender and the Canon 2X II Exteneder plus the Kinko pro 3200
    All i can say is Wow I got my answer but I also asked the differance betweem the Canon 1.4 II Extender versis the new Canon 1.4 III extender but I did not get that anwer .
    The person that did these tests realy gave me the answer that I wanted .
    I have The Kinko 1.4 300 extender /The Canon 1.4 II extender & the Canon 2X II Extender .
    The Canon 9D Mark II & the Canon 70-200 Mark II lens all of the good equipment that you need to test these extenders .
    If any person has compares the Canon 1.4 II to the new Canon 1.4 mark III Extender I would love to get the answer .
    Peter C

  6. Thanks for your great efforts on this review. I am at present considering a teleconverter lens and will go for the Canon 1.4 and this complements my 24-105 L f4 and 70-200 L f2.8, working with the 7D that I am very pleased with. I am going on a Safari day shoot at Woburn at the end of this month and have the loan of a 100-400 and a Canon 2x TC, so it will be interesting to see the results. Just hope this silly weather is good on the day.


  7. Fantastic. I think this is a great test and thank you for your time. As you say the Canon 70-200mm is a very good comparable standard to start off with, same going for Canon Converter 1.4X. I find your logic good and many thanks for your time and work. I am also trying to find if the SIGMA 1.4X is comparable to the Canon and Kenko 1.4X.

  8. Great test , as i am into birding is it possible you could make a referance to the canon 400mm 5.6 used with the canon mk 11, 2 by extenders stroke teleconverters and the kenko pro 2 by extender ,any advice on suitable apatures to use to get max shrpness and contrast while these extenders when attached to my canon 7d , l love the results you pulled from your research ,keep it up we need people like you to preform real tests and present the results on sites like this , take a pat on the back from myself for presenting this research you placed here.

  9. Hi Martin,
    Wow you have worked hard!! Very informative though I got a bit lost in the detail.
    As a newcomer to Canon and the proud owner of a 5D mark 2 I am just a little frustrated by the lack of reach of my one and only lens the 24 to 105 F4 which you mentioned briefly in your article. Is it feasible to use a 1.4 teleconverter on this lens at it’s max zoom? I am trying to avoid buying a big heavy lens because of the cost and weight as I am a small person and the camera alone is heavy enough!
    Cheers, Ann (Australia)

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s