Lens Fog Risk

What it does

Estimates whether your lens or gear is likely to fog up right now, based on the live air temperature and dew point at your location. Fogging happens when a surface is at or below the dew point of the surrounding air.

What you need

• A location. Without one, the screen asks you to set it in Settings.
• A network connection. It uses live weather data, not a sensor in your phone, so it works on any device but not offline.

How to use it

1. Set your location with the Location picker.
2. Read Air Temp, Dew Point, and Fog Risk.

Reading the results

• Air Temp and Dew Point are shown in °F (imperial) or °C (metric), following your unit setting.
• Fog Risk compares the two. The gap between air temperature and dew point is the dew point spread:
  • High: spread of 4°F (about 2.2°C) or less. The air is at or near saturation, so fogging is likely if your gear is cooler than the air.
  • Moderate: spread over 4°F up to 10°F (about 5.6°C).
  • Low: spread over 10°F. There is a wide margin before condensation.
• If the live data cannot be loaded, the screen says so and shows dashes.
• This does not know how much colder your own gear is than the air, so treat it as an estimate.

Tips

• Fogging is most common when you move from an air-conditioned space or car into humid outdoor air.
• The Shoot Forecast screen has a Lens Fog Risk card that also shows the dew point spread in °F.