Everything needed to write about Apex Lucis — the facts, the boilerplate, quotes you may use without asking, and screenshots. Updated 4 October 2026.
Apex Lucis puts the tide, the light and the forecast on the same screen as the booking, the client and the invoice. Planning apps have no diary; business apps have no ephemeris. This is the one that does both, on iPhone, iPad and Mac.
Tide predictions are worked out on the device from harmonic data for over 7,500 stations in 128 countries, bundled into the app — so they work on a headland with no signal and no account. There is no Apex Lucis server and nothing to sign in to.
Three lengths, so there is one that fits. All three may be used verbatim, edited or cut, with no approval needed.
Apex Lucis is a planning and business app for working photographers. It puts the tide, the light and the forecast on the same screen as the booking, the client and the balance owing.
Apex Lucis is a planning and business app for working photographers, available on iPhone, iPad and Mac. It scores every shooting window across a photographer's saved locations by combining light quality, the forecast, the state of the tide and seasonal wildlife activity, ranks the hours worth driving for, and turns the one they choose into a booking that already carries the tide and light times for that date and place. Tide predictions are computed on the device from bundled harmonic data, so they work with no signal.
Apex Lucis is a planning and business app for working photographers, built for iPhone, iPad and Mac. Photographers currently answer one question with four apps — is this hour worth driving for? — and none of those apps knows who is paying them to be there. Apex Lucis answers it once: its Optimal Windows scan combines light quality, the Apple WeatherKit forecast, the state of the tide and seasonal wildlife activity across every location a photographer has saved, ranks the results, and turns the chosen window into a booking carrying the conditions for that date and that place.
Two things are worked out locally rather than fetched. Tide prediction runs from harmonic constituents for over 7,500 stations in 128 countries — NOAA's published harmonics in the United States and the TICON-4 global dataset elsewhere — all bundled into the app, so a prediction is available on a headland with no signal and no account. Sun, moon, twilight and Milky Way positions come from a custom ephemeris engine written for the app rather than taken from a library, accurate to about a degree against Stellarium.
Behind the planning sits the business: leads, bookings, invoices, expenses, packages, contracts, gear, trips and permits. There is no Apex Lucis account and no Apex Lucis server — records live in the photographer's own private iCloud database, and the on-device wildlife field guides are generated with Apple's FoundationModels rather than sent anywhere. Apex Lucis is free to download, with a Pro subscription at £8.99 a month or £79 a year after a 30-day trial.
Depending on what your readers care about.
A landscape or wildlife shoot turns on four things: the light, the forecast, the tide, and what is moving. Checking them one app at a time is why most photographers end up guessing — and none of those apps knows there is a client expecting pictures. Optimal Windows ranks the hours across every saved location, and the one you pick becomes a booking with the conditions already on it.
Tide prediction is harmonic analysis: given the right constants for a place, the height at any moment is computable from first principles. Apex Lucis bundles those constants for over 7,500 stations and does the arithmetic on the phone. No network, no account, no rate limit — which matters because the tide matters most exactly where there is no signal.
No company, no funding, no team. The ephemeris engine, the tide predictor and the window scoring were written for this app rather than pulled from a library — around 845 Swift files and 750 unit tests, including station-specific tide fixtures checked against published NOAA predictions for Liverpool, Hanalei Bay and Morehead City.
From Mark Haskins, developer of Apex Lucis. Use any of these without asking.
“Photographers answer one question with four apps — is this hour worth driving for? And then none of those four knows who is paying you to be there. I wanted the answer and the booking in the same place.”
Mark Haskins, developer of Apex Lucis
“The tide matters most precisely where there is no signal. That is the whole reason the harmonic data is in the app rather than behind an API — the prediction is worked out on the phone, on the beach, with everything else turned off.”
Mark Haskins, developer of Apex Lucis
“There is no Apex Lucis account and no Apex Lucis server. Your client list is in your iCloud, not mine. I am one person, and that is a reason to trust the architecture rather than my promises.”
Mark Haskins, developer of Apex Lucis
Free to reproduce in any coverage of the app, with no credit required beyond the app's name.
Eighty iPhone screenshots are on the gallery page, arranged by module — business, planning, environment, dashboard and widgets. Right-click any image to save it at full resolution.
Everything in one download: press assets (68 MB) — twenty-one screens on iPhone, iPad and Mac, each one framed and unframed, the 30-second video, the app icon at 1024px, a portrait of the developer, and plain-text files of the captions, the data-source credits and a README.
A scan ranking the hours across every saved location, and the chosen hour becoming a booking that already carries the tide and light times for that date and that place. Captioned, no narration, so it reads with the sound off. This is the sequence no other app on the market can show.
Any of these may be embedded or linked in coverage. The 30-second one is also in the download above as an MP4, to cut into a piece rather than embed. For the longer two as files, email.
Two things worth knowing before you open it.
Start with Settings ▸ Sample Data. The app is at its most legible full of a working photographer's data: locations saved, bookings on the diary, invoices outstanding. A fresh install is an empty diary, and the thing worth looking at — the join between the conditions and the job — is invisible until there is a job to join. Adding the sample data takes a moment and removing it again is one tap.
To get access to the full range of features, consider subscribing to Apex Lucis Pro. This will unlock additional tools such as Optimal Windows, Moon Alignment, Profit and Loss, Insights, and call sheets. There is a 30 trial period which hopefully would be enough for you to fully test the application, then cancel the subscription at no cost to you.
Ask for a Pro code. Free covers the tides, the light, the forecast, the wildlife and the whole day-to-day of running a job, so there is plenty to look at without one. Optimal Windows at full scope, Moon Alignment, Profit and Loss, Insights and call sheets are behind the subscription — email and a code will come back by return. Note: These work like any other subscription and would auto-renew if unless you cancel it.
Not corrections, just the three things easiest to get slightly wrong.
The tide data comes from two sources, not one. NOAA's published harmonics cover the United States — about 3,450 stations, public domain — and the TICON-4 global dataset covers everywhere else, about 4,840 stations. “8,000 NOAA stations” is wrong on both counts, and both sources ask to be credited.
Optimal Windows is not AI. It is deterministic scoring: four measured inputs, weighted and ranked, and the same inputs always produce the same answer. The app does use Apple Intelligence — the wildlife field guides are generated on the device with Apple's FoundationModels framework — but that is a different feature, and attaching the claim to the wrong one gives away a true one.
Nothing is uploaded or hosted. Documents are written as files and handed to the photographer to send on. A booking's one-pager is an HTML file in their hands, not a page on a server — there is no Apex Lucis server to put it on.
Tide predictions are computed from harmonic constituents published by the National Oceanic and Atmospheric Administration (public domain) and from TICON-4 (Hart-Davis et al., DOI 10.17882/109129, CC BY 4.0), which draws in part on data from Copernicus Marine Service. Weather comes from Apple WeatherKit. Wildlife occurrence records come from the Global Biodiversity Information Facility (GBIF). Any coverage quoting the station count is welcome to carry the same credit.
One address, read by the person who wrote the app.
press@apexlucis.com — for review codes, assets you cannot find here, a walkthrough, or any question at all. Interviews, demonstrations and technical detail on the tide or ephemeris work are all available on request.