The Pros and Cons of Using Teleconverters (Extenders) on your DSLR

The Pros and Cons of Using Teleconverters (Extenders) on your DSLR

Canon-Ef-ExtenderHave you ever been out and about with your DSLR and wished that the lens that you had fitted could zoom in just a little more? That extra reach can be handy in many situations – but for most of us a new lens is out of our budget – so what’s a photographer to do?

One solution to the problem is to consider getting yourself a teleconverter for your lens. Teleconverters (sometimes called extenders or multipliers) are generally much cheaper than a new lens and can multiply the focal length of your lens by anything from 1.4 times to 2 times.

In this tutorial I’ll explore some of the pros and cons of teleconverters.

Tennis-1Last year I took a trip to the Australian Open Tennis and in preparation for it I treated myself to a Canon 1.4x (L) Teleconverter EF (also called extenders) to use with my 70-200mm f/4 lens.

I’d previously used this lens at similar events and while it produced some wonderful results it left me thirsting for more focal length to get even more closely framed shots of players.

Canon make two teleconverters for DSLRs – the 1.4x and 2x versions (and other manufacturers make similar models – for example Nikon’s 2x, 1.7x and 1.4x). Keep in mind that extenders don’t work with all lenses. You should check with your manufacturer before purchasing to see if you own compatible lenses. I’ll profile a few more teleconverters below.

The Pros of Tele-converters/Extenders

Focal Length – The obvious benefit of using a teleconverter on your camera is that it extends the effective focal length of whatever lens you use it with. A 1.4x converter will give you an extra 40% (extending my 200mm maximum to 280mm) and a 2x converter will give you a 100% boost (effectively giving me a 140-400mm zoom.

The benefits of this extra reach are obvious – it could turn the framing of a tennis player shot from court side from a full body shot to a tightly framed upper body shot which reveals rippling muscles, dripping sweat and the grimace of their face as they strike the ball….

Cost – In comparison to the cost of buying a 400mm lens a teleconverter is a much more economical way to go.

Weight – I don’t know if you’ve seen some of the longer lenses going around but they can be quite huge. Add a 2x extender to a smaller lens instead of getting one of the larger ones and you’ll save your back some hardship.

Minimum Focus Distance – using an extender means you can keep the minimum focus length of your lens. This can be handy when you don’t have a macro lens handy and want to get close in on a subject that isn’t far away. It won’t really compare to a dedicated macro lens – but can be handy.


The Cons of Tele-converters/Extenders

So why wouldn’t you rush out and buy a teleconverter?

There are a couple of costs (in addition to the monetary one) associated with them.

Lens Speed – The first thing to consider when using a teleconverter is the impact it has upon how much light gets into your camera.

Using teleconverters means less light gets in which means your maximum aperture will be decreased. When using a 1.4x converter this means you’ll lose one stop and when using a 2x converter you’ll lose two stops (It was for this reason that I went for a 1.4x teleconverter instead of the 2x one as I didn’t want to slow my lens down any further than f/5.6).

So last year at the tennis, instead of being able to shoot at f/4 with my camera I had a maximum aperture of f/5.6.

I was lucky that the weather was excellent on the day and there was plenty of light so this didn’t really impact my shots too much – however if you’re shooting in low light or indoors you’ll notice the impact of this more.

Camera Shake – As you extend the focal length of a lens – any movement of your camera will become more noticeable.

Using a teleconverter magnifies both your subject and any movement in your camera so you’ll want to think carefully about how to reduce it, either by increasing your shutter speed and/or using a tripod/monopod or some other technique to secure your camera.

Focusing Speed – Another consideration with tele-converters is that they slow down the speed at which your camera will focus. This will vary from lens to lens but is particularly an issue in lower light. Some lower end DSLRs will not be able to use Auto focusing at all with some teleconverters at certain aperture settings (or at all) – so do check your camera’s compatibility before buying. To get around slow focusing switch to manual focus mode and learn how to use it – you’ll be surprised how quickly you get the hang of doing it yourself – it’s a useful skill to have.

Image Degradation – Extenders multiply not only the focal length but also any aberrations of the lens you pair it with. As a result you’ll notice on many lenses that image quality suffers – I’m told this is particularly the case with longer extenders (x2) where sharpness and contrast suffer – particularly when shooting into light (where flare and ghosting can be a problem). Using the best quality lens possible will help keep such degradation to a minimum.

Overall Verdict

Using extenders/tele-converters is a more affordable way to extend your focal length than to purchase a longer lens – however the cost can be to your image quality and camera performance if you are not working with a high quality lens in decent light.

I think they are well worth using if you need the extra reach but wouldn’t use them for every shot. I definitely travel with my 1.4x extender at all times when shooting with my 70-200mm lens.

When using one try not to use them at the maximum aperture that your camera will allow – but stop it down at least one stop and you’ll find the results are significantly better. Also keep in mind that longer focal lengths will leave you with less depth of field to play with – so your focusing needs to be spot on!

Teleconverters vs Cropping

Of course the alternative to using a teleconverter or extender is to take your images with what ever lens you have and then to crop those images later in your post production phase. This is definitely the cheaper option – however in my own testing I’ve seen better results with a teleconverter. You can get away with cropping – but if you want to really blow up your images a lot the converter will be an option to consider.

Teleconverters to Consider

Canon Extender EX 1.4x II – the one I use and love. It’s not cheap when compared to some other manufacturers but does a good job. Works best when you don’t push it to the maximum aperture (pull back a stop and it produces some nice results).

Canon Extender EX 2x II – double your lens focal length with this one. Doesn’t work with all lenses and I’ve heard it can produce slightly ‘soft’ results.

Nikon AF-S TC-14E II 1.4x – I have friends with this one and the results they get are excellent. Not compatible with all Nikon lenses – but where it is it’s a great little extender – although not cheap!

Sigma 1.4x EX DG (pictured right) – I hear a lot of positive things about this 1.4x extender. Sigma make them for all the major DSLR manufacturers and they are compatible with many lenses (check first though). It works best with a smaller aperture than wide open but for it’s price it looks like one to consider. You can get it for Canon, Nikon, Pentax and Minolta and Sony lenses.

Sigma 2x EX DG – another sigma option which also gets good results by all reports. Sigma again make it for all the major manufacturers including – Canon, Minolta and Sony, Nikon, Sigma, Pentax lenses.

Feel free to leave your own recommendations and experiences of Teleconverters and extenders below.

Read more from our Cameras & Equipment category

Darren Rowse is the editor and founder of Digital Photography School and SnapnDeals. He lives in Melbourne Australia and is also the editor of the ProBlogger Blog Tips. Follow him on Instagram, on Twitter at @digitalPS or on Google+.

Some Older Comments

  • Kyle Borreson July 19, 2013 04:11 am

    There is always going to be some degradation no matter which brand you use, you're adding more glass between the image and sensor... I haven't noticed too much aberration, but then I haven't blown the images up to 400% to inspect closely... For me, the doubled reach is worth the cost of light. However, last week at the rodeo I attended (the calgary stampede) my camera failed to drive the auto focus due to the reduced aperture. .

  • SK July 19, 2013 01:51 am

    Have you found it a major problem that you loose two stops with your Kenko x2 converter, especially in low light and have you noticed deterioration in quality when using, say, canon 70-35mm lens?

  • Kyle Borreson July 15, 2013 11:21 am

    The canon extenders are only compatible with a select range of their ef lenses... The sigma teleconverters are just arts restricted on what lenses they mate with, I believe the kenko teleconverters mate to Any ef lens (at least they made to all the ef lenses I own)
    Dr John Varghese, if you're using the kit 18-135 with the 550d (t5i) that's an ef-s lens, and none of the teleconverters I've seen will be usable with it.

  • dr jogi varghese July 13, 2013 05:51 am

    am using canon eos 550d slr with 18 -135 lens. can I use a macro or tele converter with it??? is there any disadvantages for this??? what about the approximate price??? please give ur valuable suggestions

  • Kyle b July 13, 2013 02:01 am

    I was wrong in my previous post... The canon extenders do Not mate to any ef lens... I was working off faulty information... Sorry if that confused anyone...

    Sk, I don't believe that the canon extenders are compatible with your lens... But the kenko ones are, I have both the 1.4 and 2x kenko converters, and am generally quite happy with the results.

    I went with the kenkos as opposed to the canons for two reasons... The kenkos seem to mate to any canon ef lens, and are cheaper. I haven't had the chance to do a direct comparison of the two brands (I don't have a canon extender or a lens the canon would mate to).. But if anyone is willing to lend me both... :-P

  • Sk July 12, 2013 12:38 pm

    How does the Canon converter compare with equivalent Kenco converter please?

  • Sk July 12, 2013 12:33 pm

    I have a canon 500d and my zoom lens is Canon 70-300mm, is the Canon EF 1.4X II Extender compatible with my equipment please?

  • Kyle Borreson March 3, 2013 12:25 am

    Canon tc's work with all canon ef lenses, they don't work with ef-s lenses since the "s" lenses seat farther inside the body, since they're designed to be used with crop bodies with smaller mirrors...

    So yes, the canon tc's will work with your 75-300mm ef lens.... But you'll lose one stop of light on the 1.4tc and 2 stops on the 2tc.... the 1.4 would give you a max apeture of 5.6 at the wide end of that lens, and the 2 would give a max of 8 at the wide end.

  • Christina Johnson January 14, 2013 10:38 am

    would a tc work with a EF 75-300 f/4-5.6 ??? Canon lens..Rebel T3 camera

  • peter anders December 24, 2012 11:48 pm

    i have learned a bit of knowledge

  • Rumel April 20, 2012 08:41 am

    can i use Canon Teleconverters 1.4 with 18-200mm lens??

  • rob jons February 15, 2012 10:17 pm

    You don't mention wide angle lenses or more specifically wide to telephoto zooms.

    Would a teleconverter work on, say, Sigma's 17-70 zoom? It would be a good travel combo if it did.

  • Rod December 19, 2011 12:28 pm

    Canon Teleconverters 1.4 and 2x do not fit with your len 18-55mm. I am using an additional EF-S 50-250mm

  • Rav4bustit December 7, 2011 04:23 am

    Informative article.

    Question: I am new to photography with my 550D having a kit lens (18-55mm IS) only...Having a tight budget for a telephoto lens, instead i am up to having a telephoto converter lens instead 1.4x or 2x... Any suggestions?

    Thank you

  • Sanjay November 15, 2011 04:10 am

    Great Article! and gave me good insights about teleconverters about which I had minimum knowledge. Thank You

  • lee January 19, 2011 08:35 pm

    Why do most teleconverters not compatible with a Canon 55-250mm lens????

  • John McMaster January 11, 2011 11:43 pm

    I have an old 'Televar' ( Kenko?) 1.7 teleconverter left over from 35mm days.
    On either my Canon 50D, or 20D, the exposure comp. has to be set back to one stop under. Even then the image is still not as good as a cropped blow-up .
    I wonder if Canon Teleconverters are any better ?

  • Photoblogger January 21, 2010 03:07 pm

    Great article! I noticed that the teleconverters here are the ones attached to the base first. There's this new kind of teleconverters made by Chinese claimed to be by Japanese Technology.

    (I separated the .asp so as not to consider this spamming.)

    Any thoughts with this new kind of teleconverter?

  • John O'Brien January 18, 2009 02:54 pm

    Good evening,I have both the Nikon D40 & D40X,I have the Quantary 2XDG,I have found it disables the AF-S funtion on Nikon lenses,I suspect it disables the VR function as well.I have several non auto focus for these cameras & use the Tele Converter on will cause less light so one will have to adjust arpiture & shuter speed with this accesory.I use the converter mainly out side with camera mounted on a tripod for wild life shots & landscape photos when a ""fast"lens & fast auto focus is not neccesary.
    I would have bought the Nikon model for a lot more bucks but got this due to the price & if I lied it I was planning on the Nikon model but it does the same thing concerning the AF-S function.
    I would recomend it as it is fun to play with but remember it has its limatations.
    ps: it does work well with the 50mm Nikor af 1.8

  • SueQ54172 October 6, 2007 02:30 pm

    Question...I have a Canon G7. It's not a DSLR but will a teleconverter have the same effect as far as less light being able to enter the camera? I just ordered a package with a teleconverter and a wide angle attachment and I didn't know about this. Will the wide angle have the same effect too?

  • knafland September 17, 2007 05:38 pm

    Well, mine is only IS :( Anyway, if any of you guys have some photos, where difference with and without converter is shown (regular photos), please contact me!

  • Mark September 15, 2007 06:20 am

    Knafland - Mine is the f4 IS too....the 2.8? If only!

  • knafland September 15, 2007 05:14 am

    Looks like all of you guys have 2.8 IS, while i am still at the F4 one like the author of this article (i suppose). Do you have any images for comparision with and without the extender, as i see that the examples in given tests are looking quite bad :(

    Thanks in advance!

  • Bob Helman September 14, 2007 11:41 pm

    I use an Olympus 1.5 on my Panasonic FZ 50 p&s with 12X zoom.
    I find that astabilizatio works fine provided all other conditions are met such as good light. But there often is degredation. Stabilization fails in lower light at max zoom so I have to both increase light and back off full zoom. But that being said the zoom lens can be as bad in poor light.

  • Mark September 14, 2007 07:24 pm

    A timely piece this, for me, as I'm considering the option of an extender.

    The one question I do have is regarding Image Stabilisation. If I use my 70-200IS with an extender will I still have use of the IS. I tend to think I wouldn't as the stabilisation wouldn't carry through to the teleconverter....but just want to check I'm correct on that assumption. Thanks

  • Rudolf Leitgeb September 14, 2007 06:04 pm

    There is a comparison of Canon and Kenko teleconverters on

    Note, that the page is in german, but enen for the non german speakers of you the images should tell you a lot, especially if you scroll down to the comparison test images.

  • Raghu P September 14, 2007 02:53 pm

    Nice article well explained.
    A question:- Will Image stabilization (IS) continue to work with a TC mounted ?

  • xavier September 12, 2007 11:33 pm

    i was considering about adding a teleconverter to my 70-200, but found the price at nikon quite high. I did not think about aternatives such as Sigma's and kenko's thanks for the tip.
    Also i guess i will loose the VR, not a big deal, but i have to check that.

  • Robert Gottofrey September 11, 2007 05:02 pm

    I would mention the converters from Kenko as well. They are a good option if you wish to be able to use a converter with a canon lens which is not supported by the canon converters.