View source for Sigma 4.5mm f/2.8 EX DC Circular Fisheye HSM lens

{{Short description|Fisheye lens for APS-C cameras}}
{{Infobox photographic lens
| name         = Sigma 4.5mm f/2.8 EX DC circular fisheye
| image        = Sigma 4.5mm circular fisheye lens.jpg
| caption      =
| maker        = [[Sigma Corporation]]
| feat-is      = n
| focusdrive   = [[Ultrasonic motor]]
| feat-sbf     = n
| feat-macro   = n
| feat-special = circular fisheye
| application  =
| type         = circular [[fisheye lens]]
| flength      = 4.5mm
| flength-eq   =
| fov          = 180 degrees
| aperture     = f/2.8
| groups       = 9
| elements     = 13
| diaphragm    = 6
| close-dist   = 13.5cm
| max-mag      = 1:6
| max-diameter = 76.2mm
| max-length   = 77.8mm
| weight       = 470g ''(16.6oz)''
| filter       = rear (Gelatin filter)
| hood         = none
| case         =
| av-horiz     = 180
| av-vert      = 180
| av-diag      = 180
| start        =
| stop         =
| replace      =
| msrp         = $1400
}}
The '''Sigma 4.5mm f/2.8 EX DC circular fisheye''' is a [[photographic lens]] manufactured by [[Sigma Corporation]]. It is a circular [[fisheye lens]], designed to project a 180-degree field of view in all directions onto a circular image.  It is the first such lens to provide the complete circular fisheye effect on [[crop factor]] [[Digital single-lens reflex camera|digital SLR cameras]], which do not have a full 36x24mm sensor.<ref>{{cite web |title=Sigma 4.5mm F2.8 EX DC Circular Fisheye HSM |url=http://sigmaphoto.com/lenses/lenses_all_details.asp?id=3336&navigator=6 |accessdate=2009-08-21}}</ref>  This lens is available in [[Canon EF lens mount|Canon]], [[Nikon F-mount|Nikon]], [[Sigma SA mount|Sigma]], [[Pentax K mount|Pentax]] and [[Sony α|Sony]] mounts.
This lens projects a 13mm image circle, which fits nicely in a [[Micro Four Thirds system]] frame with an adapter.
==See also==
*[[List of Nikon compatible lenses with integrated autofocus-motor]]
* [[Sigma 10mm f/2.8 EX DC Fisheye HSM lens]]
== References ==
<references/>
{{Sigma lenses}}
[[Category:Sigma lenses|004.5mm f/2.8 EX DC circular fisheye]]
[[Category:Fisheye lenses]]
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