===== Pentax-M SMC 100mm f/4 Macro ===== 
{{ :lens:pentax-m_smc_100mm_f4_macro.png?200|}}
==== Summary ====
The SMC Pentax-M 100mm f/4 Macro is a compact, manual-focus macro lens introduced in 1977 and produced until 1984, designed for full-frame K-mount film cameras. It delivers 1:2 magnification natively and can reach 1:1 with extension tubes, making it a versatile tool for close-up, product, and nature photography. Optically, it features a 5-element/3-group design, Super Multi-Coating (SMC), and a 6-blade automatic diaphragm. It stops down to f/32, focuses as close as 45cm, and provides a 0.5× reproduction ratio. The lens uses a 49mm filter thread, weighs 355g, and measures 64.6 × 77.5mm. It lacks an “A” setting on the aperture ring, so it’s best used in manual or aperture-priority modes on modern digital bodies. A dedicated hard case was included, and while a PH-R49 hood fits, it’s rarely needed thanks to the deeply recessed front element.
==== Tech Specs ====
| Manufacturer    |Pentax|
| Series          |M Series Macro|
| Model           |SMC|
| Focal Length    |100mm|
| Max Aperture    |f/4|
| Min Aperture    |f/32|
| Format          |Full-Frame|
| Image Circle    |-|
| Minimum Focus   |45cm|
| Focus Rotation  |°|
| Iris Blades     |6|
| Optical Design  |5/3|
| Squeeze         |none|
| Front Diameter  |64.6mm|
| Filter Thread   |49mm|
| Focus/Zoom Rod  |none|
| Native Mount    |Pentax K|
| Data Protocol   |none|
| Length          |77.5mm|
| Weight          |355g|
| Body Telescope  |-|
| Body Material   |-|
| Focus Drive     |-|
| Iris Drive      |-|
| Zoom Drive      |-|
==== History ====
Country of Origin:  \\
Release Date: 1977 \\
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 ====