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CapXer

About CapXer

A director's viewfinder is a small handheld tool for previewing a shot without the camera. CapXer brings that idea to the browser, adds your phone or webcam as a live view, and explains the ideas behind it in short, cited lessons.

Licence

CapXer is free to use. Its source code is public under a source-available licence, which is not an open source licence. Read the terms in the LICENSE file.

The full list of third-party software and data is in the THIRD_PARTY.md file.

Credits

CapXer is built with the following software. Thank you to everyone who maintains it.

  • AstroSite framework (build time), MIT licence
  • SvelteInteractive components, MIT licence
  • Tailwind CSSStyling (build time), MIT licence
  • FigtreeTypeface, SIL Open Font licence
  • JetBrains MonoTypeface for numbers, SIL Open Font licence

Exposure aids

The histogram, zebras, false colour and focus peaking on the live camera are measured on the video your browser receives. That picture has already been through your phone's or webcam's own automatic exposure and processing. It is not RAW, and not the log signal of a cinema camera, so treat the aids as a guide to light and contrast, not as a light meter.

Brightness is measured as luma from the BT.709 video standard. There is no industry standard for false colour: every camera maker uses its own table. CapXer places its bands around an 18% grey card using the BT.709 video curve. Phones shape their picture with their own curve, so the stop labels are approximate.

Camera data sources

Every sensor size, phone and webcam angle of view, guide and exposure-aid level in CapXer comes from one of these sources: the maker's own specifications or a published standard. Each value records exactly where in the source it was found.