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Sigma 20mm f/1.8 EX DG RF
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Reviews
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Views
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Date of last review
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1
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1010
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Mon December 3, 2007
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Recommended By
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Average Price
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Average Rating
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100% of reviewers
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None indicated
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7.0
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Description:
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Super wide-angle lens with a large aperture of F1.8 and angle of view 94.5°. It has Macro focusing capability with a minimum focusing distance of 20cm/7.9inches (reproduction ratio 1:4). It incorporates an aspherical lens element in the front as well as rear lens groups, to minimize distortion, spherical aberration and astigmatism.
Key Features
# Lens construction: 13 elements in 11 groups
# Focusing system: Rear Focusing
# Angle of view: 94.5°
# Number of diaphragm blades: 9
# Minimum aperture: F22
# Minimum focusing distance: 7.9 in. (20cm)
# Maximum magnification: 1:4
# Filter size: 82mm
# External finish: EX finish
# Lens hood: Perfect hood with Bayonet Mount
# Dimensions: 88.6mm (dia) x 87mm (length)
# Weight: 520g
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Keywords:
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Sigma 20mm f/1.8 EX DG RF
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Author
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_MB_
Forum Regular
Registered: March 2007
Location: Northumberland, UK
Posts: 829
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Review Date: Mon December 3, 2007
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Would you recommend the product? Yes |
Price you paid?: None indicated
| Rating: 7
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Pros:
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Build, sharpness, contrast
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Cons:
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Weird focus switching, awkward focal length on a crop, 82mm filter size
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This lens was another bargain on ebay. They're fairly rare so I just went for it without any particular need for the focal length.
The copy I had was sharp, needed little help in PS to get lovely rich tones and was usable at its widest apertures which meant lots of fun at dusk! It's Sigma EX grade so expect a very good finish with solid construction throughout, internal focusing, most assured in use.
For some reason Sigma built this lens with an AF/MF switch as is normal, plus a push/pull type affair on the focus ring which also switches focus. I could never think of a reason for this. If its MF at the switch, it's MF in either focus ring position. If it's AF at the switch, you can override using the ring. Seems superfluous, perhaps they just ordered too many switches?
Filter size is big, no use for existing filter kit and expensive to get a polariser at that size for instance. I also found this lens not quite wide enough, not quite standard enough for a lot of use on a crop camera.
It has its niggles but first and foremost a lens is for taking pics and this did the job very well. I'd recommend on these grounds but be aware of the areas where you're left scratching your head and asking "why?"
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