Kelvy vs Stop Bath

Match light to your camera before you roll. Kelvy turns your iPhone or iPad into a practical white balance meter for filmmaking, photography, lighting setups, and location scouting. Measure Kelvin and green/magenta tint, identify likely light sources, and get settings tailored to your camera—not just a generic number. CAMERA-READY GUIDANCE Choose a profile for ARRI, Blackmagic Design, Canon, DJI, Fujifilm, GoPro, Nikon, OM System, Panasonic, RED, Sony, or Generic. Kelvy rounds each reading to the Kelvin and tint increments your camera supports, helping you move from measurement to setup quickly. WHAT KELVY SHOWS • Estimated Kelvin color temperature • Green/magenta tint shift • Camera-specific white balance and tint settings • Likely light-source category • CTO/CTB gel suggestions for balancing mixed lighting • A live color-temperature graph BUILT FOR THE WAY YOU WORK • Capture and save readings with thumbnails and location details • Export branded photos with measurement overlays • Copy Kelvin values with one tap • Apply an offset to match a trusted meter or camera body • Choose to open Kelvy directly to the Light Meter FREE TO USE Kelvy includes 5 captures every week at no cost. Kelvy Pro unlocks unlimited captures. Measurements are camera-based estimates and may vary by device, reference surface, exposure, and mixed lighting. For best results, aim at a neutral white or gray reference under the light you want to measure. For critical color work, compare with a calibrated meter. SUBSCRIPTION INFO Kelvy Pro is available as an auto-renewable subscription. Payment will be charged to your Apple ID account at confirmation of purchase. Your subscription automatically renews unless canceled at least 24 hours before the end of the current period. You can manage or cancel your subscription in your App Store account settings. Privacy Policy: https://kelvyapp.com/privacy Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

A timer for people who develop their own black-and-white film. Pick your film, developer and temperature, and Stop Bath lays out the whole process — pre-soak, develop, stop, fix and wash — timing each step and prompting you when to agitate. The timer covers black-and-white processes only. The negative viewer works with both black-and-white and colour negatives. TIMES FROM THE DATASHEETS Development time depends on the film, developer, dilution and temperature. Every time in Stop Bath comes from a manufacturer datasheet, and the source shown on screen opens the original document so you can check it yourself. Where no official time exists, Stop Bath does not invent one. It says so plainly and offers an external reference for further research. BUILT FOR AN ACTUAL DARKROOM • Clear current-step and remaining-time display • Agitation reminders at the right moments • Swipe between processing steps • Drag the progress bar within the current step • Full safelight-red mode • Screen stays awake while timing • Celsius and Fahrenheit support SEE THE RESULTS Photograph a negative, place the sampling box over the frame and tap Invert. Fine-tune black point, white point, gamma, contrast and red/blue balance, then save the result to Photos. The negative viewer is designed for quick inspection and selection; it does not replace a dedicated film scanner. PRIVACY Stop Bath works entirely offline: • No account or sign-in • No ads or analytics • No personal data collection • Images are processed only on your device • Photo Library access is add-only and cannot read your library English and Chinese. Designed for iPhone and iPad.