Support — Pontus Camera Tools

Pontus

Camera Tools

Support Guide

Overview

Pontus Camera Tools is a two-tool reference app for cinematographers and directors. It gives you a full-screen Focus Chart and a ColorChecker Classic on your iPhone — both designed to be used directly in front of a camera on set.

No internet connection required. No account needed. The app works fully offline.

Focus Chart

What it does

The Focus Chart displays a full-screen Siemens star pattern — a radial test target used to verify sharpness and resolve fine detail across the frame. It lets you confirm whether a lens is focused accurately at your working distance and aperture, without needing a physical test chart.

How to use it

  1. Open the app and tap Focus Chart.
  2. Place the iPhone at the distance of your subject — or wherever you need to verify focus.
  3. Open your lens to its widest working aperture. Depth of field is shallowest here, so focus errors are easiest to spot.
  4. Shoot a frame, or monitor live through your viewfinder or external monitor.
  5. Examine the result, paying close attention to the centre of the star.

What to look for

The radial spokes should taper to a sharp point at the centre with clean, defined edges. If the centre looks smeared, blurry, or shows a moiré pattern (a circular banding effect), the camera is not focused precisely at the target plane.

  • Smearing at the centre — indicates front or back focus
  • Moiré or banding — typically front or back focus at fine detail
  • Clean, sharp spokes — focus is accurate

Tips

  • Use a tripod or locked-off camera so camera shake doesn't confuse the result.
  • Check at multiple apertures if you're shooting across a range.
  • For zoom lenses, check at each focal length you plan to use — parfocal behaviour can vary between lenses.

ColorChecker Classic

What it does

The ColorChecker Classic tool displays an on-screen recreation of the Calibrite ColorChecker Classic — a 24-patch colour reference chart. It's primarily designed for matching colour between cameras on a multi-camera shoot.

Shoot the chart on each camera under identical exposure settings, then use the clips in your colour grading tool to align the patches. This gives you a consistent colour baseline across every angle before the grade starts.

Colour spaces

The app supports four colour spaces. Switch between them using the controls on screen:

sRGB Display P3 Adobe RGB Rec. 709

Match the colour space to the working colour space of your camera or delivery spec. If unsure, start with sRGB — it covers most standard log profiles and broadcast deliverables.

How to use it on a multi-camera shoot

  1. Turn True Tone off before you start (see the True Tone section below).
  2. Open the app and tap ColorChecker Classic.
  3. Set the screen to full brightness.
  4. Place the phone in front of the first camera at the same position your subject will occupy.
  5. Match your exposure so the grey patches read correctly on your histogram — aim for clean patches without clipping.
  6. Shoot the chart and note your exposure settings (ISO, shutter, ND).
  7. Repeat on every other camera using the same exposure settings.
  8. In your colour grading tool, pull up all the chart clips and align the 24 patches across cameras. This creates a matched baseline before any creative decisions.
ℹ️

Physical chart vs. on-screen chart

A physical colour chart responds to real light — the patches reflect actual photons, which react to your lighting colour temperature, lens character, and sensor response in a way a screen cannot replicate. This on-screen chart is a practical stand-in for multi-camera matching, not a substitute for a physical chart in a calibrated workflow.

True Tone

⚠️

Disable True Tone before shooting the colour chart

True Tone adjusts the white point of the iPhone display to match the ambient light in the room. That's the opposite of what a reference chart needs to do. If True Tone is on, the patch colours will shift depending on where you are, making the chart unreliable.

How to turn it off

  1. Open the Settings app on the iPhone.
  2. Go to Display & Brightness.
  3. Toggle True Tone off.

You'll need to turn it off each time you restart the phone if your default is on. The fastest on-set workaround is to add Display & Brightness to your Control Centre (Settings → Control Centre), so you can reach the toggle without navigating through menus.

Workflow Tips

  • Use the same iPhone on every camera during your project. Screen brightness, colour profile, and rendering are consistent within a single device — mixing iPhones introduces variables.
  • Keep the phone at the same angle and distance across setups. Angle of incidence affects how light from the screen reads on the sensor.
  • Set the screen to full brightness before shooting the chart. Anything less introduces inconsistency between setups.
  • Shoot the chart at the start of each day and again if lighting conditions change significantly — moving between interiors and exteriors, changing HMI colour temperature, and so on.
  • If you're using a gimbal or handheld rig, shoot the chart on a locked-off camera whenever possible to eliminate motion as a variable.

FAQ

Does the app require an internet connection?
No. Pontus Camera Tools works completely offline. There is no account, no login, and no data is collected or transmitted.
The colour patches look slightly off. What's wrong?
The most common cause is True Tone being enabled. Disable it in Settings → Display & Brightness. Also check that screen brightness is at 100%. If you're in a very warm or cool environment, ambient light falling on the screen itself can affect how cameras read the colours.
Can I use the Focus Chart for video autofocus testing?
Yes. Display the chart, record a slow push toward the phone, and review the footage to see how your AF system handles the transition from defocused to sharp. It's a useful way to check AF hunting behaviour and speed.
Why does the Siemens star show coloured fringing on my footage?
Coloured fringing around the radial spokes is a sign of lateral chromatic aberration in the lens, not a focus issue. It's most visible at wide apertures and toward the edges of the frame. This is normal lens behaviour and can be corrected in post.
What's the best colour space for LOG footage?
It depends on your camera and log profile. For most standard formats (S-Log, C-Log, V-Log), use sRGB as the chart reference and apply your LUT stack in the grade before aligning the patches. If you're working in a P3 pipeline end-to-end, use Display P3.
True Tone keeps turning back on. Is there a way to lock it off?
Not within the app — True Tone is an iOS system setting. The fastest workaround is to add Display & Brightness to your Control Centre (Settings → Control Centre), so you can toggle it directly from the lock screen without going into Settings.
Can I use the colour chart under tungsten or HMI lighting?
Yes, but ambient light falling on the phone screen will mix with the screen's emitted light. Keep the phone shaded from direct practicals and position it facing the camera lens. The goal is for the camera to read the screen's emitted colour, not a mix of screen and reflected room light.

Pontus Camera Tools  ·  For support, use the App Store support link on the app's product page.