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Darksite guide

How do I log an astronomy observation in the field without ruining my night vision?

Last updated: 7 September 2026

Use dim red light only, and never let a white screen or a bright keyboard reach your eyes. A red headlamp and a paper log work. A phone works too, but only if every screen, including the keyboard, stays red. That is the part most apps get wrong, and it is the part Darksite is built around.

How to log at the scope and keep your dark adaptation

  1. Give yourself 20 to 30 minutes in the dark before you log anything. Full dark adaptation takes about that long, and one white flash sends you back to the start.
  2. For paper, use a red headlamp on its lowest setting. Point it at the page, not at your face, and switch it off between entries.
  3. Write less. A time, an object name, a code for how it looked (easy, faint, averted vision only) and a quick sketch. Fill in the sentences indoors the next day.
  4. Or speak. A voice memo takes a few seconds and needs no light at all. Transcribe it later while it is still fresh.
  5. If you use a phone, drop the brightness to the minimum and turn on your phone's red tint or colour filter setting. Test it indoors first: open the keyboard, pull down the notifications, and see what still flashes white.
  6. Keep the phone face down between entries, and turn off notifications for the night.

How Darksite does it

Red field mode renders every Darksite screen deep red on near-black with a brightness floor, so there is no white flash on any screen. Because the system keyboard cannot be themed, Darksite ships its own red keyboard. Big-step controls and voice capture let you log an observation in seconds without losing your dark adaptation. On iPhone and Android the app folds down to a one-handed red deck you can work at the eyepiece.

The entry itself is built for the dark. Each observation has a round eyepiece-view sketch field, a seeing and transparency scale, NELM and SQM, and a voice clip captured at the scope, all red-safe, all on your device. Your gear is already in the gear locker, so picking the telescope and eyepiece you used is a tap, not typing.

Red field mode is in the free tier. The free tier includes an unlimited observing log, the gear locker, the Messier life-list up to 70 objects, and backup, restore and export. Darksite Pro is a one-time in-app purchase of $29.99. It unlocks the full observing-programs library, coordinator-ready exports and week-ahead planning. There is no subscription.

No account, no login, no cloud. Darksite is local-first: your gear, logs, sites and life-lists stay on your device, and there are no ads or tracking. Your dark-site coordinates never leave the device.

Darksite runs on iPhone, iPad, Mac, Android and Windows. It is on the App Store, the Mac App Store, Google Play and the Microsoft Store now. On Mac and Windows it opens as a wide planning desk. On iPhone and Android it folds down to a one-handed red deck you can work at the eyepiece.

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Related questions

Does Darksite's red mode cover the keyboard?
Yes. The system keyboard cannot be themed, so Darksite ships its own red keyboard. No Darksite screen shows white in red field mode.
Can I log an observation by voice?
Yes. Each observation can hold a voice clip captured at the scope, so you can record what you see in seconds and add detail later.
Is red field mode free?
Yes. Red field mode is part of the free tier, along with the unlimited observing log and the gear locker.

Darksite is a Trueframe Digital app. Pay once, no account, your data stays on your device. See the Darksite page for screenshots, the full feature list and prices.