Simmod Lens launches M42-LPL ProLock conversion system for Pentax Takumar lenses

Simmod Lens launched what they describe as a professional way to convert old Pentax Takumar lenses for cinema use. The new all-brass Simmod M42-LPL conversion system adapts practically all M42 screw mount lenses onto the new modern LPL cinema mount standard.


For Pentax Takumar SMC M42 lenses, the system has the added benefit of the ProLock system to prevent the lens from unscrewing in use (this feature only works with original Pentax SMC Takumar lenses with a locking pin and does not work with older Pentax Takumars or M42 lenses from other brands).

m42lpl no bg

To hold the lens into place a clever submount is fitted with a rear locking tab that fits over the Pentax lens’ pin. This is then secured with screws and fitted to the LPL mount part, which again has more screws for security. Once installed, the Simmod M42-LPL conversion system provides a robust connection between the lens and camera body or Simmod LPL lens adapter with no play or wiggle.


Fitting the Simmod M42-LPL conversion system can be performed by anyone competent in DIY lens modification or by a qualified lens technician like those at any one of Simmod’s global network of approved installers. The conversion system also comes complete with a set of shims to guarantee infinity focus is achieved. As with any other high-end cinema lens, a Pentax lens with Simmod M42-LPL conversion will require calibration for optimal performance.

Pentax Takumar

Old Pentax Takumar M42 lenses offer unique vintage color renditions, beautiful flares, and distinctive bokeh, making them popular with many filmmakers. In addition, Takumars are known for their smooth and precise manual focus control with well-damped focus rings. They also have a solid all-metal build quality and a compact design.


When adapting old Pentax Takumar M42 lenses to modern video cameras, users may encounter a notable drawback related to the rotation of the lens during mounting – one of the key reasons that Pentax and other camera makers eventually moved away from screw mount to bayonet mounts. M42 lenses typically require a screw-mount lens adapter for attachment to modern camera systems, and the nature of this adapter can result in the lens rotating slightly when mounted. This rotation can pose challenges, especially when using follow-focus systems or lens gears for precise focus pulling.



The Simmod Lens LPL conversions are a cost-effective way to use these vintage lenses. If a user wanted to modify vintage stills lenses to be universally used between top-end cinema, professional, and mirrorless cameras, then the standard option was PL mount. Unfortunately, this meant most vintage stills lenses would require an expensive full cine re-housing or a costly bespoke mount-only PL conversion. Users can benefit from positive locking and greater compatibility without unnecessary expense.

The LPL mount is designed to work with larger sensors and has a wider diameter than the PL mount (62mm vs 55mm for PL). It can be found on the ARRI Alexa LF, Mini LF, Alexa 65, and Alexa 35. The Sony Venice/Venice 2 and most RED DSMC2 and DSMC3 cameras can also be fitted with LPL mounts.


LPL adapters are expensive; Simmod Lens solved this problem by coming out with its own range of professional-grade LPL adapters that sell at a much lower price point than the current alternatives. Available for LPL to Sony E, LPL to RF, LPL to L-mount, and LPL to PL, each adapter is robustly constructed of solid brass and stainless steel.

Works with Essence Magnetic Rear Diffusion Filters

image processing20230929 20338 pig0qk

The Simmod M42-LPL conversion system is also compatible with the company’s Essence Rear Magnetic filter system for quick and easy diffusion filter changes. Changing filters takes seconds once a Simmod Rear Magnetic Pilot guide is fitted. It also has the advantage of being smaller and lighter than screw-on or matte box-mounted filtration. One small single filter size fits multiple lenses, and there is no need for heavy matte boxes, multiple step-down rings, or larger, more expensive filters for wide-angle lenses. Currently, Simmod Lens offers Essence Rear Magnetic filters in Aria Black Mist filters in 1/8, 1/4, and 1/2 strengths, as well as Aria Glisten filters for a glimmer effect in 1/8 , 1/4, 1/2, and 1 strengths.

Price and Availability


The Simmod Lens M42-LPL conversion mount set costs $189 US and is available to purchase now from the company’s website.

Subscribe to our newsletter