===== Pentax SMC 135mm f/3.5 ===== 
{{ :lens:pentax_smc_135mm_f3.5.png?350|}}
==== Summary ====
The SMC Pentax 135mm f/3.5 (K-series) is a first-generation manual-focus telephoto lens introduced in 1975 for the Pentax K-mount system. It was part of the original wave of bayonet-mount lenses that replaced the M42 screw-mount Takumars, and it reflects that transitional era with its solid, all-metal construction and classic optical design. With a 135mm focal length and a relatively modest f/3.5 maximum aperture, it was designed as a compact, affordable option for portraiture, nature, and general telephoto use—offering reach without the bulk or cost of faster lenses. Optically, the lens employs a 4-element, 4-group design and a 6-blade automatic diaphragm, stopping down to f/32. It focuses as close as 1.5 meters and delivers a 0.11× magnification ratio. The 52mm filter thread and 365g weight make it easy to carry, and its 88mm length gives it a balanced feel on both film and digital bodies. Unlike later M-series versions, it lacks a built-in hood, but it was typically sold with a clip-on metal hood and a dedicated hard case. The engraved name on the barrel reads “SMC PENTAX 1:3.5/135,” and it was only produced for a short time—between 1975 and 1977—before being replaced by the more compact M-series version.
==== Tech Specs ====
| Manufacturer    |Pentax|
| Series          |K Series Prime|
| Model           |SMC|
| Focal Length    |135mm|
| Max Aperture    |f/3.5|
| Min Aperture    |f/32|
| Format          |Full-Frame|
| Image Circle    |-|
| Minimum Focus   |150cm|
| Focus Rotation  |°|
| Iris Blades     |6|
| Optical Design  |4/4|
| Squeeze         |none|
| Front Diameter  |63mm|
| Filter Thread   |52mm|
| Focus/Zoom Rod  |none|
| Native Mount    |Pentax K|
| Data Protocol   |none|
| Length          |88mm|
| Weight          |365g|
| 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 ====