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.
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.
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 http://georghofmeyr.com/galleries/Reviews/
Happy shooting and take care out there - its lion country!
March 2015; Pretoria