Why Is My Follow Focus Slipping Off the Lens Gear? And How Do I Fix It?

If you’re a videographer or filmmaker, you know how crucial it is to nail those smooth, precise focus pulls. A follow focus is an essential tool that allows you to adjust the lens’ focus smoothly and accurately while filming. However, one frustrating issue that can arise is when your follow focus starts slipping off the lens gear, causing shaky footage and missed focus points.

In this article, we’ll explore the common causes behind this problem and provide actionable solutions to help you keep your follow focus securely in place and functioning optimally.

Common Causes of Lens Gear Slipping & How to Fix Them

Improper Gear Alignment

For a follow focus to work correctly, the gears on the follow focus and lens need to mesh together seamlessly. If the gears are misaligned, it can cause the follow focus to slip off the lens gear.

Solutions:

1. Adjust the follow focus mount position by loosening and tightening the screws incrementally until the gears align properly.
2. Use shims (thin pieces of material like plastic or metal) to fine-tune the gear alignment if necessary.
3. Check for any obstructions or debris between the gears that could be causing misalignment, and remove them carefully.

Loose Follow Focus Attachment

A loose connection between the follow focus and the support rods can lead to instability, causing the follow focus to shift and slip off the lens gear.

Solutions:

1. Tighten the mounting screws that secure the follow focus to the support rods, being careful not to over-tighten them.
2. Use a two-rod follow-focus system for added stability and reduced twisting or leverage issues.
3. Ensure the follow focus baseplate is properly secured to the rods without any play or looseness.

Incorrect Gear Size or Material

Follow focus and lens gears come in different sizes and materials, and using incompatible gears can result in slippage. This is often referred to as the gear module (MOD) compatibility.

Solutions:

1. Identify the correct gear size for your lens by consulting the camera/lens manuals or manufacturer websites.
2. Consider investing in high-quality, more grippy gear materials like metal or reinforced plastic, as they are less likely to slip.
3. Check for any signs of gear stripping or deformation, which could indicate the need for gear replacement.

Worn or Damaged Gears

Over time, gears can become worn or damaged due to normal wear and tear, improper use, or incompatible gear materials, leading to a loss of grip and increased likelihood of slippage.

Solutions:

1. Replace worn or damaged gears with compatible replacements recommended by the manufacturer.
2. Maintain your gears by keeping them clean and free of debris using compressed air or a soft brush.
3. Avoid excessive force when using the follow focus, as this can accelerate gear wear.

Lens Support Issues

Proper lens support is crucial to prevent twisting and binding, which can also cause gear slippage. Longer or heavier lenses may require additional support components.

Solutions:

1. Use rod clamps, lens support brackets, or dedicated follow focus units with built-in lens support to prevent twisting.
2. Consider adding additional support components like lens support rigs for longer or heavier lenses.

Follow Focus Quality

While budget-friendly follow focus options are available, it’s important to remember that lower-quality units may have higher slippage risks due to poorer tolerances and materials used in their construction.

Solution:

Consider investing in a reputable brand known for quality follow focus units, as this can help ensure better build quality, durability, and a smoother user experience.

How to Keep Your Follow Focus Gear in Shape?

1. Regularly check gear alignment and tightness of mounting screws.
2. Clean gears periodically to remove dirt and debris.
3. Avoid excessive force when using the follow focus.
4. Consider using a lubricant specifically designed for camera gears, but exercise caution against using generic lubricants that could damage the equipment.
5. Some follow-focus models may require calibration to ensure smooth operation and prevent slippage, so calibrate properly.

By addressing the common causes and following the recommended solutions, you can minimize the frustration of a slipping follow focus and achieve smoother, more reliable focus pulls during your video productions.

Can I use any type of lubricant on my follow-focus gears? 

It’s generally not recommended to use generic lubricants on your follow-focus gears, as they may contain ingredients that could potentially damage or degrade the gear materials over time. It’s best to use lubricants specifically designed for camera equipment and follow the manufacturer’s recommendations.

Can I mix and match gear sizes between my follow focus and lens? 

It’s generally not advisable to mix and match gear sizes, as this can lead to compatibility issues and increase the risk of slippage. Always ensure that the gear sizes (MOD) on your follow focus and lens are compatible to ensure proper meshing and grip.

Can I use a follow focus on any lens? 

While follow focuses are designed to work with a wide range of lenses, it’s important to ensure compatibility between the follow focus and your specific lens. Factors like gear size, lens diameter, and lens design can all impact compatibility. Consult your equipment manuals or the manufacturers to verify compatibility before use.

By addressing these common issues and following the recommended solutions, you can minimize the frustration of a slipping follow focus and achieve smoother, more reliable focus pulls during your video productions.