Sigma 4.5mm f/2.8 Fish-Eye Lens Review

Sigma announced the arrival of their 4.5mm fish-eye lens last November, along with a 10mm f/2.8 EX DC HSM fish-eye. It is the first digitally optimised circular fisheye designed exclusively for use with DSLRs incorporating an APS-C sized image sensor.
Therefore, if it is attached to a film of full-frame camera, the circular image will appear smaller. The Sigma 4.5mm has a stunning 180º angle of view in all directions, but it has been designed with Special Low Dispersion (SLD) glass in order to minimize chromatic aberration – a common lens flaw resulting in loss of sharpness and also colour fringing.

When you look through a true fish-eye lens, it’s easy to understand why they are named so. They exhibit a huge degree of barrel distortion, casting circular images on the sensor. Thanks to their hugely wide angle of view, they are suited to astrophotography and scientific applications – for example, recording cloud distribution or the vegetation distribution of a forest.
However, in day-to-day photography, their distortion is more commonly used for creative effect. It was the fish-eye’s creative potential that appealed to me, so I couldn’t wait to get my hands on the lens when Sigma kindly offered to loan me one for a week or two.
Despite its relatively modest dimensions – the lens is only 77.8mm in length – this is a solid lens and not light at 470g. The EX finish gives it a feeling of quality and it is bundled with a padded case and slip-on adapter ring – designed to allow a lens cap to attach in order to protect the protruding front element.
The first time you bring the camera to your eye and look through the viewfinder, you just can’t help but say ‘wow’. This focal length is so impressively wide that you just can’t appreciate it until you’ve tried it for yourself. Tip the camera downward slightly, and your feet or leading tripod leg are suddenly included in the frame and anything nearby, either side of the camera, will be seen in the viewfinder.
Whilst this means that you have to use the lens with extreme care to ensure that you don’t include elements within the photo that you didn’t intend to – such as your own shadow – the wide angle of view means that this lens has huge creative potential. By getting near to your subject you can exaggerate the distortion further – perfect for shooting wacky, unflattering portraits, or to create the impression that a building is curving inward. Practically any subject has the potential to work well, and while the fish-eye effect is subjective, (you either love it or hate it) the results, in my opinion, can be stunning.
The Sigma 4.5mm fish-eye has a minimum focusing distance of 13.5cm and a maximum magnification ratio of 1:6. However, in reality, 
I found that at small f/stops, the subject remains sharp at just a few centimetres from the front element. In fact, when peering through the lens, it is tricky to judge just how near you are to the subject – an inquisitive cow I was photographing actually nudged the lens, simply because I was oblivious to just how near the animal was to me as I was shooting it.

Filters cannot be mounted on the front of this lens, due to its shape and nature, but this one was designed to incorporate a gelatin filter holder at the rear of the lens. Sigma includes a ‘guide plate’, which can be used as a template for cutting out ‘filters’ from square gels, which are available in many camera shops.

Pro verdict
This lens is great fun to use and lets you look at the world in a unique way. The shots it enables can be very eye-catching, but some practise is required to realise its full creative potential.
The lens is solid and well constructed, with good image quality thanks to the SLD glass. Focusing can prove difficult, due to the wide depth-of-field, which makes it unclear where the exact point of focus is.
However, the lens performed well overall.
It is worth shopping around for this lens, as I’ve seen it advertised for as much as £824 and as low as £500. But, even at the lower price, this is a big investment and, while I feel it is good value for money, you should be sure that you would use it regularly before buying one.
I enjoyed using it so much that I am tempted to buy one, but first, I want to be sure that the novelty of its effect won’t wear off after a few months of use. If you fancy a circular fish-eye for a DSLR with an APS-C type sensor, this lens will not disappoint!

SPECIFICATIONS
Guide price: £599
Street Price: £550
Lens construction: 13 elements in nine groups (includes an SLD glass element)
Maximum aperture: f/2.8
Minimum aperture: f/22
Minimum focusing distance: 13.5cm
Filter: rear gelatin filter holder
Maximum magnification: 1:6
 Diameter x Length (mm): 76 x 77.8mm
Weight: 470g
AF fittings: Canon, Nikon and Sigma
Contact: 01707 329999
www.sigma-imaging-uk.com