Hello! Looks like you've found my page where I keep some personal tools. Stay if you like. Perhaps you might find something useful. Your data lives in your browser storage. Click “Save to file” to download the full html file with current changes. This page specifically is for saving nice colors you find.
Build named palettes with any number of colours. Import .ase or .json swatch files, and export palettes back out as .json for later storage. Click “Save to file” to download the full html file with current changes.
Work out a display's pixel density, aspect ratio, and the viewing distance at which it crosses into "retina" territory.
Pixels per degree (PPD) sets the visual acuity you're calculating for. It's commonly assumed that 60 PPD is enough — that's what Apple used to define "Retina" — but we know that it isn't. Some research [Nat Commun 16, 9086 (2025)] suggests 120 PPD is enough for the 99th percentile of viewers, and around 100 PPD for the 66th. For me personally, 100 PPD is sufficient — an estimate based on using a 4K 27" screen at 25" and 35" viewing distances — so it's the default here.
32 inch monitor and 50 inch TV (both in Lawrence) had comfortable distance of about 42 inches and 60 inch (actual 84 inch) respectively, i.e. 37 degrees FOV, which can be used as max. Also, coincidentally that is when a 4k screen becomes retina for me. Although, at 130" distance, 65" TV felt pretty big (manageable but not bigger def). So human brain does nonlinear processing.
If horizontal pixels is and vertical pixels is , diagonal length is , pixels per is and field of view in radians is , then
pixels per inch
where is the horizontal screen size,
.