Photography News 03

Lens review Sigma 12-24mm f/4.5-5.6 II DGHSM

SPECS

aperture, and to the edges of the frame. It’s already well into the Excellent zone at maximum aperture, gets a little bit better at f/5.6, then holds a very high standard to f/11 before the inevitable diffraction take over. It’s really only the edges at 24mm that show any sign of noticeable weakness and that’s not too bad. Peak resolution in the MTF 20% test measured an impressive 118 lines-per-mm. Verdict The Sigma 12-24mm is full of nice surprises. The 122° field-of-view at 12mm is unrivalled, with high build quality and smooth handling for a decent price, and best of all it’s sharp – very sharp. There are some caveats though, such as a tendency to flare in very bright light and the difficulty with using filters. Also, this lens really only makes sense on full-frame cameras, and then it’s so wide that sometimes you can have too much of a good thing.

First impressions are very favourable. It feels meaty, closer to the hefty Tokina 16-28mm than the smaller APS-C super-wides, with Sigma’s newer smooth black surface finish. Zoom and focusing rings are just right, with no lumps or slop, and nicely weighted. It feels very well made. Like some other very wide lenses, the bulbous front element protrudes, protected by a fixed lens shade. This effectively rules out the use of filters, and that will disappoint a lot of landscapers. There are adaptor filter kits available, but they’re cumbersome, expensive affairs. Sigma has made one significant optical design concession, and that’s restricting the maximum aperture. Running from a modest f/4.5 at 12mm to only f/5.6 at 24mm, this helps improve every aspect of performance, and saves a lot of extra bulk. Images are good, amazingly good. Tested on full- frame format, this lens is sharp, right from maximum

PRICE £600 CONTACT sigma-imaging-uk.com FORMATS Full-frame and APS-C OPTICALDESIGN 17 elements in 13 groups GLASSTYPES 1x SLD, 3x FLD, 4x aspherical APERTURERANGE 6 rounded blades ANGLEOFVIEW Full frame 122° to 84°, APS-C 1.6x 97° to 59° MINIMUMFOCUS 0.28m (from sensor) MAXREPRODUCTION RATIO 1:6.4 MANUALFOCUS Full-time override FILTERSIZE Via third- party adaptor WEATHERSEALED No DoFSCALE Yes, applies 12mm only DIMENSIONS (DxL) 87x120mm WEIGHT 670g ACCESSORIES Case supplied. Hood built-in FITTINGS Canon, Nikon, Pentax, Sigma, Sony AUTOFOCUS Ultrasonic HSM f/4.5-5.6 to f/22 DIAPHRAGM

%MTFat24lines-per-mm(full-frame)

Howitrates

Centre 81+ 60+ 83+ 61+ 79+ 60+ 73+ 58 f/5.6 f/8 f/11 f/16

85+ 69+ 86+ 74+ 84+ 76+ 78+ 71+ 71+ 63 f/4.5 f/5.6 f/8 f/11 f/16

86+ 70+ 87+ 74+ 84+ 72+ 80+ 68+ 73+ 58 f/5 f/5.6 f/8 f/11 f/16

24mm

Sharpness12mm

17mm

Edge

FEATURES

22/25

100 090 080 070 060 050 040 030 020 010 000

Ultra-wide-angle is unique, but aperture range is limited and using filters is difficult HANDLING Quite heavy, but feels solid and well made, with very nice zoom and focus controls PERFORMANCE Excellent sharpness. Aberrations control better than expected for such a wide lens VALUE FOR MONEY Not exactly cheap, but Canon and Nikon rivals cost considerably more OVERALL

25/25

23 /25

24/25

ABOVE Considering how wide this lens is, and that it’s for full-frame, sharpness is impressively high. The modest max aperture helps a lot here. It’s strongest at 12mm, especially in the centre, but edges aren’t far behind. A reduction in edge sharpness towards the longer end is hardly a deal-breaker.

94/100

Tamron SP 10-24mm f/3.5-4.5 Di II LDAspherical (IF)

SPECS

APS-C sensor equates to around 15 megapixels so it exceeds the theoretical maximum there, without taking into account the effect of an anti-aliasing filter that would reduce the camera’s potential further. Sharpness at the edges takes a further dip, as is always the case, falling to quite modest levels below f/5.6 at the mid and long end. However, edge performance isn’t too badly hit at 10mm, and at f/8 and f/11, sharpness nudges the Very Good standard at all focal lengths right across the frame. Verdict With the company’s good reputation, we had high hopes. In direct comparison with other similar lenses, the Tamron doesn’t measure up quite so well. On all other aspects, it is very much on the money. Aberrations control is more than acceptable, autofocus is good, and it’s a nice lens to use – quality made, in a compact package, for a good price.

This lens is nicely finished, with smooth and well- weighted zoom and manual focusing controls. One concession to cost is the autofocus mechanism, driven by micro-motor rather than ultrasonic, and the ring turns during focusing – though importantly, the front of the lens does not. There’s no full-time manual override, with manual focusing engaged by a switch. In use, the AF worked very well, decently fast and hardly any noisier than most ultrasonics, so really no complaints there. Filter size is the popular 77mm, and it comes with a lens hood. Performance, though, is not as good as expected. It’s not at all bad, particularly in the centre, and that never strayed below Very Good with little difference between focal length settings, even at the longer end which often happens. In the peak resolution test at MTF 20%, the Tamron scored 101 lines-per-mm, at 24mm f/8 in the centre. This is lower than some, but to put that in context, 100 lines-per-mm on an

PRICE £370 CONTACT intro2020.co.uk FORMATS

APS-C 1.5x and 1.6x OPTICALDESIGN

12 elements in 9 groups GLASSTYPES 1x HID, 2x LD, 4x aspherical APERTURERANGE

f/3.5-4.5 to f/22 DIAPHRAGM

7 rounded blades ANGLEOFVIEW

APS-C 1.6x 107° to 59°, APS-C 1.5x 110° to 61° MINIMUMFOCUS 0.24m (from sensor) MAXREPRODUCTION RATIO 1:5.1 AUTOFOCUS Micro-motor MANUALFOCUS AF/M switch FILTERSIZE 77mm non-rotating WEATHERSEALED No DoFSCALE No DIMENSIONS (DxL) 83x87mm WEIGHT 406g ACCESSORIES Hood supplied FITTINGS Canon, Nikon, Pentax, Sony

%MTFat36lines-per-mm(APS-C)

Howitrates

66+ 41+ 65+ 49+ 64+ 48+ 63+ 48+ 62+ 47+ 59+ 44 f/3.5 f/4 f/5.6 f/8 f/11 f/16

60+ 26+ 59+ 33+ 58+ 44+ 58+ 46+ 57+ 43 f/4 f/5.6 f/8 f/11 f/16

Centre 60+ 35+ 67+ 41+ 68+ 43+ 65+ 46+ 59+ 47 f/4.5 f/5.6 f/8 f/11 f/16

24mm

Sharpness10mm

16mm

Edge

FEATURES

25/25

100 090 080 070 060 050 040 030 020 010 000

Very versatile zoom range, 10-24mm is widest in this class. 77mm filters, hood supplied HANDLING Light, smooth operating, compact. AF is not ultrasonic, but performs just as well PERFORMANCE Sharpness is disappointing overall, though rises to a good standard when stopped down VALUE FOR MONEY At £370, considering the focal length range covered, it’s good value OVERALL

25/25

18/25

20/25

ABOVE Given its range, handling and price, this lens’s performance is disappointing. Centre sharpness is always Very Good, but edges fall noticeably behind, with a dip at lower f/numbers and at mid range lengths. Having tested three samples all with similar results, we have to conclude this is representative.

88/100

Photography News | Issue 3