Tamron SP 350mm F/5.6 Model 06B: The SP 350mm delivers excellent optical performance, is the same diameter as the SP 500mm F/8, but is somewhat shorter in overall length. Its surprising that other manufacturers, after introducing their 500mm F/8 mirror lenses, didn't think of the idea of producing a similarly sized lens which is 1 F/stop faster. Thus the 350mm F/5.6 by Tamron was born! Most importantly, Tamron did an excellent job of minimizing off-axis vignetting (light fall-off) and in obtaining very good off-axis optical performance. Minolta, for example, produced their very compact 250mm F/5.6 mirror lens, but the Minolta 250mm had somewhat noticeable off-axis vignetting. Note that the Minolta 250mm F/5.6 mirror lens is, nevertheless, an excellent performer. Tamron, however, realized that compactness wasn't the most desirable design attribute if off-axis vignetting was not minimized and if off-axis performance was not optimized. Tamron correctly realized that, due to the fixed the dimensions of the 35mm film format, that 350mm is approximately the minimal focal length for which a high performance mirror lens can be designed which has minimal off-axis vignetting. Thus the SP 350mm F/5.6 is the same diameter as the SP 500mm F/8 mirror lens, yet has minimal vignetting and, amazingly, also has excellent off-axis optical performance. Accurate focusing is critical since the secondary mirror obstruction diameter is around 50%. The SP 350mm focuses down to 43.3 inches (1.1 meters) for a 1:2.5 macro reproduction ratio. Always use the included lens hood for maximum contrast. This is one of very few mirror telephoto lenses which actually can be hand held without using either a monopod or a tripod.

Lens Specifications:

Lens Model	06B
Focal Length	350mm
Aperture Range	f/5.6
Angle of View	7.3°
Optical Construction (Groups / Elements)	4 / 7
Min. Focus from Film Plane	43.3" (1.1m)
Macro Mag. Ratio [w/2X Converter]	1:2.5 [1:1.25]
Filter Size	30.5mm rear (82mm front)
Diameter	3.4" (86mm)
Length at [w/Nikon mount]	2.9" (74.5mm) [3.1" (79mm)]
Weight	20.4 oz. (577g)
Lens Hood (model #)	Screw-in type #19FH, reversible.
Accessory	Accepts SP 2X tele-converter #01F. Supplied wth tripod mount ring and lens hood. Additional 30.5mm rear filters and 82mm front filter available as optional extras.