Photography Guide

How to photograph patients so Symetri’s AI alignment is fast, accurate, and consistent every time.

Introduction

The quality of your Symetri results depends directly on the quality of your photos. Symetri uses AI-powered face alignment — detecting up to 10 landmark regions including eyes, nose, mouth, brows, and face contour — to automatically align your before and after images for a precise, professional comparison.

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The Four Golden Rules

These apply to every shot you take:

Same angle every time

Before and after must match in yaw (left/right rotation), pitch (up/down tilt), and roll (head tilt).

Same distance every time

Keep the camera the same distance from the patient’s face across sessions.

Camera at eye level

The lens should be level with the patient’s eyes — not above, not below.

Consistent, diffuse lighting

Avoid hard shadows across the face. They obscure the landmarks the AI uses for alignment.

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How Symetri Sees Faces

Symetri’s AI scores each photo’s landmark quality on a 4-point scale before deciding how to align your pair:

Score	What it means	Alignment quality
4 / 4	Both eyes clearly visible, nose and mouth detected	Highest precision — 4-point alignment
3 / 4	One eye clearly visible, nose and mouth detected	Good — 3-point alignment
2 / 4	Nose and mouth only (face turned away)	Basic — 2-point alignment
< 2	Landmarks not detected	Fallback to face bounding box

Keep both eyes in frame and unobstructed whenever the treatment allows. That’s the difference between a score of 4 and a score of 2.

The 28° Rule

When the face is rotated more than ~28° away from camera, the AI switches from its highest-quality 4-point alignment to a simpler 2-point mode using only the nose and mouth — because at that angle, the far eye becomes unreliable. This is by design.

What this means: If you’re shooting a 3/4 view, both photos need to be at exactly the same degree of turn. A 28° before and a 35° after will produce a visible alignment mismatch.

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General Setup

Equipment

• iPhone (rear camera, 1× lens) — the primary lens. Avoid ultrawide (0.5×) which distorts facial proportions.
• Tripod or stabilized arm — eliminates distance variation between sessions.
• Ring light or softbox — even, diffuse illumination positioned directly in front of the patient, level with the face.
• Neutral background — white, light gray, or medium gray.

Mark the floor with tape for where the patient stands and where the tripod sits. This ensures every session starts from the same spot.

Ideal Framing by Treatment Profile

Profile	Top of frame	Bottom of frame	Width
Full Face	1–2 cm above hairline	Chin + 3 cm	Shoulders barely visible
Forehead	2–3 cm above hairline	Tip of nose	Face edge to edge
Eyes	Top of brows + 2 cm	Mid-nose	Ear to ear
Lips	Nose base + 1 cm	Chin + 2 cm	Corner to corner + 3 cm
Side Profile	1–2 cm above hairline	Chin + 3 cm	Full profile — forehead to back of head

Common framing mistakes:

• Too close: Forehead or chin cut off. The face detector uses the full face contour — clipping it degrades alignment.
• Too far: Face occupies less than ~30% of the frame. Detection still works but precision drops.
• Camera tilted: Even a small roll causes a corrective rotation that may not match perfectly — keep the grid lines level.

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Frontal Photos

Frontal is the highest-quality mode for Symetri. Both eyes are detected, giving full 4-point landmark alignment.

Patient Positioning

• Patient faces directly into the camera. Both eyes equally visible and equidistant from frame edges.
• The nose tip should point straight at the lens — no chin lift, no chin drop.
• Hair pulled back off the face. Stray hair over one eye forces the AI into 3-point (one-eye) mode.
• Eyebrows relaxed. Squinting reduces landmark confidence.

Chin Angle

Use the Frankfort horizontal plane as the gold standard: the line from the tragus of the ear to the infraorbital rim should be level with the floor. In practice: the patient looks straight ahead, eyes level with the horizon — not at the camera screen.

Lighting

• Ring light centered directly behind the camera, level with the patient’s eyes.
• No overhead downlighting — it casts heavy shadows under the eyes and nose.
• No sidelighting — it creates asymmetric shadows that can confuse eye detection.

Frontal Checklist

1. Both eyes fully open and visible
2. No hair across either eye or brow
3. Nose tip pointing directly at lens
4. Face centered horizontally in frame
5. Camera level with patient's eyes
6. Hairline to chin fully in frame

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Side Profile Photos

Side profiles are the most demanding for Symetri’s AI. At 90°, only the nose and mouth are used as anchors — rotation correction is disabled. Your camera angle must be identical between before and after.

90° vs. 45° Tradeoff

Angle	Alignment quality	Consistency requirement
45° (three-quarter)	Higher — both eyes may be visible	Must replicate angle precisely (±5°)
90° (true profile)	Lower — nose + mouth only	Must replicate angle precisely (±2°)

Recommendation: Pick one standard and stick to it. A 45° view gives Symetri more to work with.

Profile Checklist

1. Consistent angle — mark the floor with tape to standardize turn
2. Ear on camera side fully visible
3. No hair across nose or mouth
4. Chin level — not lifted or dropped
5. Camera at eye level, not above or below

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Eyes Profile Photos

The Eyes profile zooms into the periorbital region using a 1.2× focus with the eyes as the anchor point.

Shoot the full face as normal — Symetri’s Eyes profile handles the zoom digitally. Do not zoom in with the iPhone camera. This preserves all pixel data for alignment before the crop is applied.

• Eyes open naturally — not wide-open, not squinting.
• A ring light centered on the lens will produce a consistent circular catchlight. Avoid double catchlights from two light sources — they can confuse the eye landmark detector.
• Avoid strong overhead light that creates a heavy shadow under the brow bone.

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Lips Profile Photos

The Lips profile zooms into the mouth region using the mouth centroid as the anchor point.

• Lips at rest — slightly parted (2–4 mm) is acceptable.
• Use the same expression for both sessions. A pout vs. rest position will throw off alignment.

Wait at least 2 weeks post-filler before shooting the after photo. Swelling in the first 1–2 weeks alters the lip border shape and will affect the AI’s mouth contour detection.

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Forehead Profile Photos

The Forehead profile zooms into the upper third of the face.

• Hair pulled completely off the forehead — hairline must be fully visible in both shots.
• Patient looks straight ahead. Avoid chin lift (shortens visible forehead) or chin drop.
• Eyebrows relaxed — not raised or furrowed. Don’t ask the patient to raise their brows for the photo.

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Lighting Reference

Lighting setup	Quality	Notes
Ring light, centered, eye level	Excellent	Consistent catchlights, even coverage
Bilateral softboxes, 45°	Excellent	Even, shadow-free
Single softbox, 45°	Good	Slight shadow — keep consistent
Window light (cloudy day)	Good	Diffuse and even
Window light (sunny day)	Fair	Changes throughout day
Overhead downlighting	Poor	Heavy under-eye and nose shadows
No controlled lighting	Avoid	Varies session to session

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Common Problems and Fixes

Problem in Symetri	Likely photography cause	Fix
After image shifts on case open	Camera angle or chin position changed	Re-shoot; use Manual Alignment as temporary fix
Face appears off-center or clipped	Patient too close or framing too tight	Move patient back; ensure full face in frame
Images don’t align on one side	One photo is slight 3/4 vs. the other	Standardize angle; use a wall reference mark
Eyes not detected / blur misplaced	Hair over eyes, squinting, or shadows	Pull hair back; adjust lighting
Lips profile shows misalignment	Different lip expression between sessions	Same expression — lips lightly closed or parted

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Quick Reference Card

SYMETRI PHOTO PROTOCOL

SETUP
  ✓  Tripod on taped floor marks
  ✓  Camera at patient's eye level
  ✓  Ring light centered, eye level
  ✓  Neutral background

EVERY SHOT
  ✓  iPhone rear camera, 1× lens
  ✓  Lock exposure on patient's face
  ✓  Grid lines level
  ✓  Full face in frame (hairline to chin)
  ✓  Same angle as before session

FRONTAL  →  Both eyes visible, nose to camera
PROFILE  →  Mark floor angle, ear to camera
EYES     →  Full face frame, eyes open naturally
LIPS     →  Lips at rest, same expression both times
FOREHEAD →  Hair off forehead, brows relaxed

NEVER
  ✗  Zoom past 1×
  ✗  Shoot in different lighting than before
  ✗  Let patient change chin angle mid-session
  ✗  Crop in-camera before shooting