Terms

Last updated October 8, 2026

These terms cover your use of Parhelia at parhelia.vercel.app, a free page published by PaintedApp, LLC of Portland, Oregon. Using the page means you accept them. They are short because the page asks nothing of you: no account, no payment, no data.

What Parhelia is for

Parhelia traces sunlight through idealised ice crystals and draws the halos and arcs they would make. It is for learning how halos form, for teaching, and for comparing a photograph you took with the sky a set of crystals would draw. You may use it, link to it, take screenshots of it and show it in a class or a talk.

What it is not for

Parhelia is a model, not an observation and not a forecast. It does not know what is in any real sky. Do not use it to make decisions about flying, driving, sailing or safety, and never look at the Sun directly, with or without a photograph to compare.

How exact it is

The page shows its own receipts: the figures it computes beside the published ones it was checked against, and a list of what it does not model. The tracer handles one crystal per ray, ideal prism shapes and seven wavelengths of light. Those limits are stated on the page. Within them it is as exact as the test suite says, and no more.

Your photos

A photo you compare stays on your device and stays yours. PaintedApp never receives it, so it claims no rights in it.

Our work and others'

The page, its code and its drawings are © 2026 PaintedApp, LLC; the source code is licensed under the MIT licence. The refractive index of ice comes from Warren and Brandt (2008). The colour-matching functions are the CIE's, under CC BY-SA 4.0. Some published values are quoted from Wikipedia under CC BY-SA 4.0, and the page credits every source by name.

No warranty

Parhelia is provided as it is, without any warranty, express or implied, including fitness for a particular purpose. It may change or go offline without notice.

Liability

To the fullest extent the law allows, PaintedApp, LLC is not liable for any loss arising from your use of Parhelia. The page is free, so our total liability for any claim about it is limited to what you paid to use it, which is nothing. Some places do not allow these limits, and there they apply only as far as the law permits.

Law

These terms are governed by the laws of the State of Oregon, USA, and any dispute belongs in the courts of Multnomah County, Oregon.

Changes and contact

If these terms change, the date at the top changes with them. Questions go to PaintedApp, LLC, 1327 SE Tacoma St #394, Portland, OR 97202, support@painted.app.