smc PENTAX-DA* 1:4 300mm ED [IF] SDM

Maker	Pentax
Technical data
Type	Prime
Focal length	300mm
Focal length (35mm equiv.)	450mm
Aperture (max/min)	f/4 / f/32
Close focus distance	140 centimetres (55 in)
Max. magnification	0.24x
Diaphragm blades	9
Construction	8 elements in 6 groups
Features
Manual focus override	Yes
Ultrasonic motor	Yes
Weather-sealing	Yes
Unique features	Quick-shift focus, SP (Super Protect) coating, filter window, detachable tripod mount
Application	Supertele
Physical
Max. length	184 millimetres (7.2 in)
Diameter	83 millimetres (3.3 in)
Weight	1,070 grams (38 oz)
Filter diameter	77mm
Accessories
Lens hood	PH-RBK 77 mm
Angle of view
Diagonal	5.4 °
Retail info
MSRP	1,399.95 USD

The smc PENTAX-DA* 1:4 300mm ED [IF] SDM is a supertele prime lens for Pentax K-mount. It uses Pentax' silent SDM motor for autofocus on compatible cameras (K10D^[1] and K200D upwards), and has Quick Shift Focus to allow manual adjustments in autofocus mode.

Reception

Photozone reviewed the lens favourably, stating, "in terms of resolution and contrast the lens is able to produce very good results straight from the max. aperture setting" and "mechanical quality of the lens is absolutely exceptional thanks to high quality materials and seals against dust and moisture". Of the ultrasonic autofocus motor, they wrote that it "works like a breeze - it's both fast and almost silent." Overall, they concluded that the lens is "highly desirable lens for sports and wildlife photographers."^[2]

ColorFoto wrote the lens had outstanding sharpness over the entire frame, even wide open,^[3] and PopPhoto.com said that "images shot in the field were satisfyingly contrasty and sharp."^[4]