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Photography News Issue 24 absolutephoto.com
Tests
Kenko 2x Teleplus HDDGX teleconverter £279
Specs
Price
£279
Mount Canon EF/EF-S Construction 5 elements in 3 groups Coating Digital Multi-coating Diaphragm coupling Fully automatic Light loss 2 EV Minimum focus Same as prime lens Depth-of-field Half of the prime lens In the box Pouch, front and back caps Dimensions (lxd) 35.8mm Weight 157g Contact intro2020.co.uk
If you’ve not encountered thembefore, a teleconverter is a compact optical accessory that fits between the lens and camera body and increases the lens’s effective focal length by a factor of 1.4x, 1.7x or 2x, depending on the model. So fitting this 2x teleconverter to a 70-200mm results in a lens of 140-400mm. Fit anything optical between the objective lens and the camera body and there is an inevitable impact, so there is a loss of optical quality as well as loss of light. A 2x converter gives a 2 EV light loss, so fitting Kenko’s latest addition to a 70-200mm f/4 lens turns it into a 140-400mm f/8 lens. With the excellent high-ISO performance of current digital cameras that is not the headache it used to be with film, but it remains an issue even on bright days. This Kenko 2x teleconverter sells for £279 and it has the advantage of full coupling so the camera and the lens can communicate fully via the converter, meaning exposure control and autofocusing are maintained. You even get the correct EXIF data on your files. AF is only maintained if the camera’s AF system can handle the lower light levels reaching the sensor through the lens/converter combination. You might find that the AF is working at your DSLR’s AF sensitivity limit so its responsiveness is dulled, and youmight even find that manual focusing is needed. The Kenko features five elements in three groups and multi-coating to optimise light transmission and minimise flare. It’s solidly built, too, with a comfortable grip. The unit’s only control is the lens lock release button and no issues with that. I tried the teleconverter with a Canon EOS 5D Mark III and a Canon 70-200mm f/4 L USM telezoom. It’s a decent lens but not the best Canon offers and this highlights an important consideration. A teleconverter can’t improve the quality of the lens, it can only impact on it negatively, so using the best lens possible to minimise quality loss is obviously a very good
thing. The resulting Raw files were processed in Lightroom CC with default sharpening. The Mark III with that lens worked well providingswift, smoothandnear- silent AF. With the converter added nothing changed, and even though the lens was an effective f/8 AF even indoors it was impressive – providing the focus point had decent contrast to work on. Even moving to an AF point away from the centre didn’t dent the AF’s performance either. InservoAFtheconvertercontinued to perform well, and in good light or contrast, tracking was decent so good job there. AF was still good with close subjects (the lens’s minimum focus is retained) in favourable conditions. For the optical part of the review, I mounted the camera to a tripod, set up the self-timer and mirror, and shot with the short, middle and long end of the zoom, using every aperture value. Open aperture performance (effectively f/8) is very good in the centre but sharpness drops at the edges and was most noticeable at 400mm. Stopping down to f/16 improved matters noticeably at the edges and in the centre, too, and it’s probably the best performing aperture. Most lenses work best two stops down so that is borne out here, but then comes the practical matter of shooting at f/16. On a cloudy day with an action subject you might need ISO 1600 or more to enable this aperture with action-stopping shutter speeds. Overall, though, the Kenko did well optically and mechanically but good camera technique is essential to make the most of the accessory. WC It was impressive – providing the focus point had decent contrast
140MM
200MM
How it rates
Verdict Teleconverters don’t seem to be as popular as they once were, but there is every reason to consider them particularly if you’re a photographer who only occasionally needs extra pulling power and can’t justify or afford a longer lens in the first place. This Kenko unit at £279 is certainly worth a look. It’s cheaper and fits more lenses than Canon’s own which is a bonus.
400MM
Shot with Kenko with a Canon 70-200mm f/4 zoom on a Canon EOS 5DMark III. The blow-ups belowwere taken from the centre (left half) and the edge of the frame (right half) to examine sharpness.
Features Retains full lens functions
25/25
140MM, F/8
140MM, F/16
140MM, F/32
19/25
Performance AF very good, optically good
Handling Compact, well built
25/25
200MM, F/8
200MM, F/16
200MM, F/32
Value for money Much cheaper than buying a long telephoto Overall Handy for those occasions when a longer lens is needed Pros Compact, works well, cheaper than Canon’s and works with more lenses Cons Light and quality loss – a problemwith converters generally, not just the Kenko 89/100 20/25
400MM, F/8
400MM, F/16
400MM, F/32
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