===== Pentax SMC 18mm f/3.5 ===== 
{{ :lens:pentax_smc_18mm_f3.5.png?250|}}
==== Summary ====
The SMC Pentax 18mm f/3.5 is a rare, ultra-wide-angle manual-focus prime lens introduced in 1975 and produced until 1985, designed for full-frame K-mount film cameras. It was one of the widest rectilinear lenses in the Pentax K-series lineup and remains notable for its compactness, optical complexity, and built-in filter system. Optically, it features a 12-element/11-group design with Super Multi-Coating (SMC) to reduce flare and improve contrast. The lens has a 5-blade automatic diaphragm, a minimum aperture of f/22, and a minimum focus distance of 25cm, offering 0.09× magnification. It delivers a 100° diagonal field of view on full-frame (or ~77° on APS-C), making it ideal for landscape, architecture, and environmental photography. It uses a 58mm filter thread, weighs 328g, and measures 63 × 61.5mm.
==== Tech Specs ====
| Manufacturer    |Pentax|
| Series          |K Series Prime|
| Model           |SMC|
| Focal Length    |18mm|
| Max Aperture    |f/3.5|
| Min Aperture    |f/22|
| Format          |Full-Frame|
| Image Circle    |-|
| Minimum Focus   |25cm|
| Focus Rotation  |°|
| Iris Blades     |5|
| Optical Design  |12/11|
| Squeeze         |none|
| Front Diameter  |63mm|
| Filter Thread   |58mm|
| Focus/Zoom Rod  |none|
| Native Mount    |Pentax K|
| Data Protocol   |none|
| Length          |61.5mm|
| Weight          |328g|
| 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: \\
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==== Notes ====
==== Media ====