Sigma 400mm f5.6 APO
This lens is a great introduction to telephoto lenses without having to break the bank. While other lenses of this focal length sell for $1000 or a multitude of that amount, this one can be yours for $100-$200. It feels very solid as it is made from metal. But Sigma made several concessions when designing this lens that are reflected in the low price. Nevertheless this lens is big and heavy enough to make you feel like a serious wildlife photographer.
Construction: 11 Elements / 8 Groups
Focal Length: 400 m
Maximum Aperture: 5.6
Minimum Aperture: 22.0
Field of View: 6° on FX / 4.3° on DX
Minimum Focus Distance: 4.0 m
Maximum Magnification: 1:9.5
Filter Size: 72 mm
Max Diameter: 85 mm
Length: 213.5 mm
Weight: 1100 g
Lens mounts: Nikon F, Canon EOS, Sony A (Minolta)
This lens provides autofocus with Nikon F-mount cameras with built in autofocus motors, Canon EOS cameras, Sony A-mount cameras and Minolta A-mount cameras. Autofocus is slow and it tends to hunt for focus. This may be due to the low maximum aperture of f5.6 as well as the lens relative unsharpness at this aperture. It is fast enough for photographing still objects, birds that sit in a tree or portraits. It is too slow for any kind of action photography such as sports or moving wild life.
This lens has beautiful soft bokeh. Out of focus areas behind and in front of the subject are undistracting and smooth. Unfortunately this softness also characterises the in focus areas. Especially wide open the lens is soft. Stop it down to f11 for maximum sharpness and still it won't impress by today's standards. Remember that this lens was designed for 35mm film photography. It is not meant for pixel peeping on a modern 20 megapixel dSLR. It is sharp enough for 10x15 cm prints and for web publication. It is not sharp enough for cropping the image or for full page prints in a magazine.
It is a big, heavy lens. Carrying it around in a nature reserve requires determination. Despite its bulk, it is easy to shoot hand held. If you hold your right hand on the camera and your left hand under the built in lens hood the camera and lens feel well balanced and the weight helps to reduce motion blur and camera shake.
The built in tripod collar works fine. Especially if you don't want to hold this heavy lens in your hands all day. Tracking birds with the lens mounted on a tripod is difficult, but that applies to all lenses.
The solid metal housing and built in lens hood are built to last forever. That cannot be said of the gears of the autofocus system which are made of plastic. My sample is alright, although it feels flimsy when manual focussing. I have seen another sample of this lens which did not auto focus anymore.
This is not the holy grail of cheap, undervalued tele lenses. It cannot compete with newer tele lenses that cost 5-40 times as much. However, if you find a good sample you can have a lot of fun photographing wildlife for little money. If you are not sure whether you need a 400mm lens and you want to try one out before investing serious money, this is a great opportunity to try a lens like that.