You need this!
On the spot, both quick to access AND accurate. Used it with my whole team to keep images in sync which helped tremendously in post. No gray card needed!
Free
In-App Purchases
About
This app transforms your iPhone into a professional tool for measuring light color temperature. It provides real-time Kelvin readings, tint values, and precise white balance settings for your camera, aiding photographers and filmmakers in achieving accurate color. It also offers gel filter recommendations and a history of readings.
✓Live Kelvin readout with real-time graph
✓Recommended camera white balance settings
✓CTO/CTB gel filter recommendations
✓Tint measurement for green/magenta shift
✓Calibration mode with gray card
✓Reading history with thumbnails
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+2
What's New in Kelvy
1.2.5
July 21, 2026
Minor bug fixes and performance improvements.
Subscription plans
Monthly
Kelvy Pro Monthly
$2.991 Month
User reviews
Developer apps
FAQ
What is Kelvy?
Kelvy is a mobile application that uses your iPhone's camera to measure the color temperature of ambient light in real-time. It provides Kelvin readings, tint values, and recommended white balance settings for your camera.
How does Kelvy help with white balance?
Kelvy analyzes the light source and recommends the nearest white balance preset (e.g., Daylight, Tungsten) and the exact Kelvin value to set on your camera for accurate color reproduction.
Can Kelvy help with mixed lighting?
Yes, Kelvy offers CTO (Color Temperature Orange) and CTB (Color Temperature Blue) gel filter recommendations. This helps you match mixed lighting conditions by suggesting the correct filters to use.
What is the calibration mode in Kelvy?
The calibration mode allows you to achieve maximum accuracy by using a gray card or a white surface. This ensures that the Kelvin readings are as precise as possible for critical color work.
How many readings can I take with the free version of Kelvy?
The free version of Kelvy allows for 3 readings to try out the app's functionality. For unlimited readings, users can subscribe to Kelvy Pro.
What are the subscription options for Kelvy Pro?
Kelvy Pro is available as an auto-renewable subscription with monthly ($2.99) and yearly ($29.99) plans. You can manage your subscription through your App Store account settings.
Does Kelvy have ads?
No, Kelvy does not contain advertisements. The app offers a free tier with limited readings and a premium subscription for full access.
On which devices can I use Kelvy?
Kelvy is compatible with iPhones and iPads, running on iOS. It is designed for mobile use, making it a portable light metering tool.