Duclos Macro Tubes
Duclos Lenses manufactures PL mount macro tubes which allow cinema lenses to achieve closer focus by creating space between the lens and sensor. The more distance you add, the closer you are able to focus. Like diopters (and unlike true macro lenses,) when using a macro tube, you are shifting the focus scale closer, not expanding it. Thus, you will be unable to focus to the far side of the scale. This is not a problem unless the shot requires an extreme rack focus from macro shot to say, the background.
We carry two strengths: 20mm and 15mm.
The 20mm is suggested for use with focal lengths of 50mm and longer. Light loss changes slightly based on focal length.
The 15mm is suggested for use with focal lengths 25mm and longer. This will shift the focus scale less than the 20mm unit, however it is compatible with more focal lengths and has less light loss.
The chart below is a sample of what the 20mm macro tube allows you to do with Cooke Mini S4's. Images on the left are what the Cooke Mini S4 minimum focus allows to photograph. The images in the middle shows the minimum focus with the Duclos 20mm macro tube. The images on the right show you the furthest you can focus with the 2omm macro tube.