===== Pentax SMC 300mm f/4 ===== 
{{ :lens:pentax_smc_300mm_f4.png?200|}}
==== Summary ====
The SMC Pentax 300mm f/4 is a manual-focus telephoto prime introduced in 1975 and produced until 1981, designed for full-frame K-mount film cameras. It was Pentax’s first bayonet-mount 300mm lens and part of the original K-series, known for its robust build and optical ambition. Though later replaced by the more compact M* 300/4, the original K 300/4 remains a favorite among vintage lens enthusiasts for its solid construction, smooth focus, and distinct rendering. It features a 7-element - 5-group optical design, Super Multi-Coating (SMC), and an 8-blade automatic diaphragm. The lens stops down to f/32, focuses as close as 4 meters, and delivers 0.09× magnification. It uses a 77mm filter thread, weighs 1020g, and measures 85 × 188mm. It includes a built-in sliding hood, plastic clip-on cap, and was sold with a dedicated hard case. There’s no “A” setting on the aperture ring, so it’s best used in manual or aperture-priority modes. Unlike its Takumar predecessors, it lacks a tripod collar, which can make long exposures more challenging.
==== Tech Specs ====
| Manufacturer    |Pentax|
| Series          |K Series Prime|
| Model           |SMC|
| Focal Length    |300mm|
| Max Aperture    |f/4|
| Min Aperture    |f/32|
| Format          |Full-Frame|
| Image Circle    |-|
| Minimum Focus   |400cm|
| Focus Rotation  |°|
| Iris Blades     |8|
| Optical Design  |7/5|
| Squeeze         |none|
| Front Diameter  |85mm|
| Filter Thread   |77mm|
| Focus/Zoom Rod  |none|
| Native Mount    |Pentax K|
| Data Protocol   |none|
| Length          |188mm|
| Weight          |1020g|
| Body Telescope  |-|
| Body Material   |-|
| Focus Drive     |-|
| Iris Drive      |-|
| Zoom Drive      |-|
==== History ====
Country of Origin:  \\
Release Date: 1975 \\
Launch Price:  \\
Design Revisions:  \\

==== Service ====
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Service Manual: (Insert link to manual here) \\
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Full CLA: **TBD hrs.**\\
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==== Cine-Mod ====
<nodisp 8>
Focus Ring O.D.: -\\
Zoom Ring O.D.: -\\
Iris Ring O.D.: -\\
De-click Y/N: -\\
Additional Notes: \\
</nodisp>
==== Notes ====
==== Media ====