Sigma Imaging (UK) Ltd

	PhotoPlus 'Fractionally larger and noticeably heavier than Canon’s 15mm full-frame diagonal fisheye lens, also on test, the Sigma boasts the same, fast f/2.8 maximum aperture and feels a bit better built. More importantly, the Sigma gave us sharper, crisper images throughout its aperture range and was particularly impressive at f/2.8. All in all, the Sigma 15mm is our top choice for a full-frame diagonal fisheye lens, and the fact that it’s £80 cheaper than the Canon is a bonus.'

	Outdoor Photography ‘With an impressively close minimum focusing distance of 15cm, this lens allows you to fill the frame with certain subjects at its maximum reproduction ratio of 1:3.8. Coupled with the dramatic angle of view and the wide maximum aperture this allows you a great deal of control over creative close-ups.’ ‘As with all of Sigma’s EX series of lenses this one has a solid feel. The focusing ring is smooth and there is no unnecessary play.' ‘It is also a real ‘go anywhere’ lens. Its compact dimensions and tough build mean that you will be confident it will stand up to the rigours of shooting in the wilderness, while the inherent depth of field, wide maximum aperture and short focal length make it a good option if you know that you are going to have to shoot handheld.’

	Professional Photographer ‘Overall resolution is excellent. The level of colour saturation and contrast are excellent, whilst chromatic aberration is minimal.’ ‘Straight lines that run directly through the centre of the frame are rendered straight, whilst straight line near the edge display considerable barrel distortion, as is to be expected with a non-rectilinear design.’

	Digital SLR User ‘Colour balance looked neutral on all the photos I took and was recorded accurately, with an excellent degree of tonal range throughout the pictures, especially in terms of shadow detail’ ‘At the beginning of this test, I must admit that I approached it with a degree of scepticism, wondering what it could add to my approach to wildlife and nature photography. At the end of the test, I knew the answer: it adds a great deal!! I was reluctant indeed to hand it back and have no hesitation in wholeheartedly recommending it’

	What Digital Camera ‘The MTF data obtained indicate good sharpness, with resolution figures above the critical 0.25 cycles-per-pixel threshold between f/5.6 and f/16. This is a very solid performance that proves Sigma’s lens truly is a serious optic that should not be dismissed as a mere gimmick.’

	Amateur Photographer 'The Suffix ‘DG’ indicates that steps have now been taken to optimise it for digital camera use. This is likely to concern the adjustment of anti-reflection coating to minimise the image degrading flare caused by reflections back into the lens from the polished surface of the photosensor.' 'Optically the Sigma 15mm f/2.8 tested here had a nose ahead of the Canon featured here.'