The extreme wide-angle lens with 180° fish-eye perspective
The F-Distagon® T* 3.5/30 CFi lens is a fast ultra wide angle lens of 'fisheye' type. It covers an angle of view of 180° over the diagonal of the frame. Its distortion characteristic and focal length are chosen so that the complete frame is utilized for information recording, including the corners. It has been designed as a special lens for scientific and technical documentation and offers therefore outstanding image quality and very even illumination from corner to corner – and all this even at wide open aperture. Focusing can be done down to just 10 cm (4 inches) in front of the front element (this equals 0.3 meters distance from the film) thus enabling breathtaking photos. So the photographer can easily close in on interesting details he wants to highlight and still have the complete situation in the same frame.
The F-Distagon T* 3.5/30 CFi lens can record a maximum of information within cramped spaces. The optical performance is so great that today's highest resolving color films can be utilized to their very limit.
The special fisheye distortion depicts a subject in the center of the frame quite largely, but captures also most of its surroundings. Up to 180° in the corners of the frame. Straight lines running through the center of the image remain straight. Circles around the center remain circles. However, straight lines being tangential to the aforementioned circles, will become bent. The closer a line is located to the edge, the more it will become bent. This effect can be clearly seen and controlled in the SLR viewfinder. So it can be used for image creation – by either exaggerating it to extremes, or reducing it down to levels where it can hardly be noticed at all.
The F-Distagon T* 3.5/30 CFi lens is an extremely interesting lens for stunning images. Be it in advertising, nature, or documentation under very cramped conditions.
|Focal length||30.6 mm|
|Aperture range||f/3.5 - f/22|
|Angular field (hor./vert./diag.)||112°/112°/180°|
|Focusing range (from film plane)||0.3 m - ∞
|Working range (from front end)||0.1 m|
|Number of elements/groups||8/7|
|Image ratio at closest range||1 : 4.2|
|Negative-size||55 x 55 mm|
|Coverage at close range||338 mm x 338 mm|
|Filter connection||M 24 x 0.5
|Dimensions||Ø 70.8 mm, length 113.8 mm|