|SMC||The super multi-layer coating is applied to the surface of lens elements. It boosts light transmission, ensures sharp and high contrast images, minimizes ghosting and flares. The smc coating is used in all Pentax K, 645 and 6x7 lenses and also in Asahi Takumar M42 lenses since 1971.|
|DA||Autofocus lens for Pentax APS-C digital SLR cameras. Has no aperture control ring and only supports electronic aperture control from the camera.|
|*||Professional lens with high quality optics and robust build. Meets the highest standards and provides excellent performance and flawless image quality unachievable with traditional optical technologies.|
|ED||The lens incorporates low dispersion elements to minimize chromatic aberrations and ensure excellent sharpness and contrast even at maximum aperture.|
|[IF]||The lens has internal focusing. Learn more|
|SDM||The lens is equipped with ultrasonic motor to provide very fast and virtually silent autofocus. Learn more|
|Position in the lineup|
|smc Pentax-DA* 300mm F/4 ED [IF] SDM||Jan 2008||⊗|
|smc Pentax-FA* 300mm F/4.5 ED [IF]||1991||⊗|
|smc Pentax-F* 300mm F/4.5 ED [IF]||1987||⊗|
|smc Pentax-A* 300mm F/4||1984||⊗|
|smc Pentax-M* 300mm F/4||1981||⊗|
|smc Pentax 300mm F/4||1975||⊗|
|Asahi Super-Multi-Coated Takumar 300mm F/4 ||1971||⊗|
|Asahi Super-Takumar 300mm F/4 [43891, 43894]||1965||⊗|
|Asahi Takumar 300mm F/4 [346, 43460]||1962||⊗|
|Asahi Takumar 300mm F/4||1958||⊗|
|Diagonal angle of view:||5.4° (Pentax APS-C)
|Lens construction:||8 elements in 6 groups, including:|
|Number of blades:||9|
|Closest focusing distance:||140 cm|
|Type of autofocus motor:||Supersonic Drive Motor|
|Full-Time Manual Focus:||Yes|
|Maximum diameter x Length:||Ø83 x 184 mm|
|Weather sealing:||Dust-proof and water-resistant barrel|
|Fluorine coating:||Front element|
|Filter size:||77 mm|
Design and Features
The build quality is excellent. The lens barrel is large, heavy, dust-proof and water-resistant, made of metal. The lens mount is metallic. The rubberized focusing ring has width of 5 cm, deeply ribbed in order to provide good grip and prevent slippage of fingers, well damped, moves smoothly in manual mode and has the angle of rotation of 240 degrees which is more than enough to perform precise manual focusing. Like all Pentax DA* series prime lenses, this model is equipped with the distance scale and a depth of field scale behind a window.
The lens features AF/MF focus mode switch.
|AF||Autofocus mode with Quick-Shift Focus System.|
|MF||Manual focus mode.|
The lens uses front filters with standard size of 77 mm which are easy to find. However, filters of such size are more expensive and mainly used with professional lenses.
The filter thread does not rotate during focusing which allows convenient use of different types of filters (including but not limited to polarizing and gradient).
Pentax offers a giant round bayonet-type lens hood as a part of the package. It features a slide-out window which enables rotation of polarizing filter without removing the lens hood.
A fluorine coating has been applied to the outer surface of the front lens element to repel water or oil drops for easier cleaning of the lens surface.
The lens is equipped with ultrasonic motor, the autofocus is virtually silent and very fast. The lens features Quick-Shift Focus System: after autofocus is achieved, the focusing ring can be turned to adjust the focus manually. This feature eliminates the need for changing the focus mode to MF.
Low dispersion elements (AD, ED, LD, HLD, SD, UD etc) and fluorite elements minimize chromatic aberrations and ensure excellent sharpness and contrast even at maximum aperture.
The sharpness is very good across the frame already wide open.
|Sensor size:||23.7×15.7 mm|
|Vignetting at F/4.0:||-0.41 EV|