How to Record Clean Sound on an Autofocus DSLR Lens

Recording high-quality video with clean audio while using the autofocus feature on a DSLR can be a challenge, especially when focusing causes unwanted noise. Here are some effective strategies to help you achieve professional-quality video recordings:

Solutions to Autofocus Noise During Recording

Autofocus noise, produced by the lens during adjustment, can ruin the audio quality of your video recordings. Thankfully, there are several methods to minimize or eliminate this issue:

1. Use a Silent Autofocus Lens

When choosing a lens with autofocus capabilities, opt for one with specific technologies designed to minimize noise.
Stepper Motor STM: Ultrasonic Motor USM:

These lenses are specially designed for video recording, ensuring quieter operation. They are often preferred by videographers due to their smooth and efficient focusing mechanisms.

2. Manual Focus Techniques

While autofocus is convenient, it may not be the best choice for silent video recording. Consider these manual focus techniques:

Pre-Focus

Set your focus manually before starting the recording. This eliminates the need for the lens to adjust during the shoot.

Focus Pulling

If you need to change focus during the shot, practice focus pulling manually to avoid focusing noise.

3. Utilize External Microphones

To further improve audio quality, consider using external microphones:

Directional Microphone

A shotgun microphone isolates the subject’s sound and minimizes background noise. Place it close to the speaker for the best results.

Lavalier Microphone

A lavalier lapel microphone clips directly onto the speaker, capturing sound directly while reducing lens noise.

4. Record Audio Separately

For optimal audio quality, record audio separately using a digital audio recorder. Sync the audio and video in post-production to achieve the best results.

5. Sound Isolation Techniques

To improve the audio quality even further, employ sound isolation techniques:

Windshield

If recording outdoors, use a windshield on your microphone to reduce wind noise.

Quiet Environment

Record in a quiet setting to minimize background noise. Finding a well-sealed room or soundproof location can significantly improve audio quality.

6. Post-Processing

Use audio editing software to clean up your audio tracks. Tools like Adobe Audition or Audacity are excellent for this task, helping you reduce unwanted noise.

7. Camera Settings

To ensure optimal audio recording, adjust your camera settings:

Manual Exposure

Set your camera to manual mode to avoid any automatic adjustments that might cause audio disturbances.

Adjust Gain

Ensure your audio levels are set appropriately to prevent distortion while capturing clear sound.

Conclusion

By using a quiet lens that supports manual focusing and external microphones, you can significantly reduce autofocus noise and enhance your video recordings. Utilizing these techniques and tools will help you achieve professional-quality audio and video. Whether you're a professional videographer or a hobbyist, these tips will help you deliver cleaner, more polished recordings.