Georg Hofmeyr | Photography blog

wildlife – nature – travel

Sigma TC1401 teleconverter – Review and sample shots

Quick field review of the Sigma TC1401 teleconverter on the Sigma 150-600mm Sports with sample shots taken with a Nikon D800

So, this morning, exited as a kid with a new toy, I head out to the Austin Roberts Bird Sanctuary to see whether the Sigma 150-600mm f/5-6.3 DG OS HSM Sports lens performs as promised with the Sigma TC1401 1.4x teleconverter mounted on my Nikon D800.

The review objective

This 1.4 times converter changes the lens to a 210-840mm f/7.1-9.0 super telephoto. It adds 40% in reach, 1 f/stop loss in aperture and adds an additional 190 g in weight, which takes the lens to 3.05Kg. What I wanted to confirm was:

  • Is it usable early in the morning at first light
  • Is the autofocus able to lock on subjects fast and reliably, including birds in flight
  • Are the resultant images still sharp enough?

The autofocus performance was my primary concern, because although the sigma website states that when the TC-1401 is attached to cameras that are compatible with AF at f/8, it is possible to shoot with AF I was still concerned  how this would work in practice and whether it provides “real world”  capabilities since Nikon also states that only eleven of the fifty-one focus points are active with lenses that have a maximum aperture of f/8 or faster.

The verdict

So what’s the verdict? Yes, yes and yes, but within the constraints of the camera's reduced ability to autofocus at f/8 with many auto-focus points being inactive. (verdict updated April 2015)

It was quite dark when I first arrived, and at 3200 ISO with shutter speeds of around 1/400, I was getting usable images - see the, full frame, no crop. Twenty minutes later the early sun was out and I was feeling more comfortable with 1/2000 sec shutter speeds to freeze it at 850mm. The Kingfisher unfortunately obliged with only one dive, with inconclusive results, mostly because I failed to keep the small fast moving bird in the centre of the viewfinder.There were lots of ducks paddling about to practice on with excellent results. Subjectively there was no observable degradation of autofocus performance with the 1.4 converter in place. This was confirmed when tracking African Holy Ibises in flight, hand-held, with two 6/6 and one 7/8 autofocus lock successes.

Yellow-billed Duck Turtle Common Moorhen Blacksmith Lapwing African Sacred Ibis African Sacred Ibis Black-bellied Whistling Duck

Mission accomplished - as one would expect with a f/9 lens, it prefers decent light, but having taken just over 300 shots in about two hours, I am now confident that this lens combination does perform adequately for my needs. It provides just that added extra reach, which I missed when moving from dx format to fx, and it does so without any significant compromise. Well done Sigma, I am quietly confident that this lens, at its reasonable price, with this purpose made converter, have the potential to become a wildlife photography classic.

For more shots taken with the Sigma 150-600mm f/5-6.3 DG OS HSM Sports lens please see my review gallery at

Happy shooting and take care out there - its lion country!

Georg Hofmeyr
March 2015; Pretoria
South Africa


11 responses to “Sigma TC1401 teleconverter – Review and sample shots

  1. I needed a repair of my Sigma 150-600 contacts (because I dropped it accidentally) before I could get the 1.4 teleconverter to work. Since last Friday, when the repaired lens came home, I have been out every day to the local refuges trying out the new combo. Overall I am thrilled with the extra reach and the focus ability, though the auto focus will hunt for awhile if the background is complex. I have to work hard to keep the focus point on my subject. Based on your suggestions, I will now try reducing the number of focus points to as low as possible to see if that helps the camera and lens do its work without the need for so much hunting. What I really like is that, when the focus locks on the subject, the focus is the sharpest it has ever been. Combined with not having to get so close to wily birds who then sit better before flying off, I can fill more of the frame making cropped files not so small. I don’t think I will take off the tele converter except under very special circumstances as I am thrilled with it. See last weeks photos here:

  2. Dear George
    Many thanks for your review.
    I also use TC1401 with 150-600 S and D800.
    When I zoom the lens over the 300mm mark and the aperture becomes larger than f8 the lens is not able to lock focus (although it hunts for it) and there is no focus confirmation ever if I try to focus manually.
    Is that expected for this combination?
    Kind regards

    • Georg Hofmeyr says:

      Hi Nikonian,

      I suspect that this happens when your selected focus point is not set on one of the focus points active or functional at f/8 for the D800. Remember that the ability to autofocus above f/5.6 is a fairly recent invention and requires functionality compromises.

      Please refer to the D800 user guide, page 373, in the fine print under the heading “The AF-S/AF-I Teleconverter”. My understanding is that when shooting at over f/8 minimum aperture, only the centre focus point acts as a cross type, and a further 10 focus points (1 above and 1 below, and four left and four immediately right of the centre cross type) will only act as line sensors. A line sensor will be more prone to “hunting” than a cross-type. This also means that 40 of the 51 focus sensors will not be functioning when using the TC1401 at longer focal lengths.

      This is however not a problem, as long as one is aware of these limitations and adapt ones focusing practices accordingly. I, for example, only use the central focus point when I have the TC1401 fitted and then I have no trouble achieving quick reliable autofocus lock all the way up to full 600mm zoom on the Sigma 150-600 sports.

      • Dear George

        Many thanks for your reply. I also only use the central focus point with the teleconverted 150-600.
        Anyways. When you lock focus at 850mm do you see the dot indicator for subject in focus on the viewfinder? I’m only able to see the two triangles (blinking) even if I have previously focused with live view or manual.

        Best regards

        • Georg Hofmeyr says:

          Hi Nikonian,

          Interesting question. I checked and yes, at 850mm I get autofocus lock through the viewfinder with a solid green dot!

          • Dear George

            From your responses I realized that there was a problem with my camera. I send it to Nikon Service and they replaced the mirror. After that the Sigma Sport lock focus with the teleconverter. Just for the record.

            Many thanks

          • Georg Hofmeyr says:

            Hi Nikonian,

            Great news – I’m happy for you that the problem is now sorted. Where can we see some of your work with this lens?
            I’m halfway through writing a short review on the 150-600 sports – hope to publish it soon.

  3. Richard E. Tolle says:

    Thanks, Greg. Your review is encouraging. I purchased the Sigma 150-600 to use on my Nikon DX D7000. I’m anxious to see the impact of the DX 1.5 multiplier coupled with the Sigma TC1401’s 1.4x. I hope to visit your area next March to try out my new lens and Nikon system. I’m an amateur but really enjoy the technology available to photographers today. Your photos are breathtaking.


  4. Hi Georg,

    many thanks for your suggestion! 🙂

  5. useful tips and beautiful shots!

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