The "F" in MFC-3F stands for adjustable friction force.

The unique feature of the new MFC-3F focus follow system is that the focus knob and drive gear form a single piece; there is no transmission in the new MFC-3F. It is a direct drive, and thanks to the elimination of internal gears, there can never be any difference between input and output movement, making it 100% backlash-free. Vocas can guarantee it! This design also allows the MFC-3F to have a "transmission" ratio of 1:1, making it ideal for lenses with reduced focus travel such as DSLR lenses and smaller cameras with integrated lenses. Moreover, thanks to the elimination of internal gears, the product's lifespan is significantly increased.

The unique shape of the drive gear teeth is what makes all this possible. These specially designed teeth can push the lens ring up or down when rotating the focus knob in the same way that a camera operator is accustomed to.

The MFC-3F has an additional function compared to the standard version, namely integrated adjustable friction. Rotating the red dial on the focus knob allows you to precisely adjust the internal friction of the MFC-3F to your preferences.

This focus follow includes the flexible Vocas gear ring, with 2 movable stops. For use with cylindrical lenses whose focus barrel diameter is between 40 mm and 110 mm.

Specifications:

- Focus knob and drive gear in one piece
- Direct drive
- Elimination of internal gears
- 100% backlash-free
- Reduced cost
- Adjustable friction force
- Adjustable internal friction