Distance and Lens in the Facial Assessment Photo

The face does not change shape, but the photo does. Someone who shoots with the camera 30 centimeters from the patient gets a face with a bigger nose, smaller ears and compressed sides. Someone who shoots from 2 meters gets more faithful proportions. That difference contaminates measurements, before/after comparisons and even the conversation with the patient. Standardizing distance and lens is one of the cheapest ways to improve plan quality.

Why does distance alter the face?

When the camera is close, the difference in distance between the nearest point (the nose) and the farthest (the ears) is large relative to the total distance, which exaggerates what is in front. It is a perspective effect, not a device defect. Wide-angle lenses, common on phones, intensify the effect, especially at the edges of the image.

In practice, in a close-up photo:

• The nose looks wider and more projected.
• The forehead and chin look different from reality.
• Symmetry is distorted by small rotations.
• The edges of the face "run away."

This bears directly on how to measure facial symmetry and on reference lines on the frontal photo.

How do you standardize?

Details of the general standard are in standardized clinical photography, camera height in camera height in the patient photo and the rear camera in front or rear camera for the clinical photo. For light and background, see lighting for the planning photo.

What about the phone lens?

Each device has different lenses, and the main camera usually has a better profile than the ultra-wide one. Avoid the ultra-wide lens for assessment. If the device offers moderate optical zoom, it can reduce distortion when combined with a greater distance. The most important thing is to use the same device and the same lens every time, so photos from different sessions are comparable.

How does this affect before/after comparison?

Before and after only say something when the variable is the face, not the camera. If the before photo was taken at 40 cm and the after at 1 m, the difference in the nose and cheekbone may come from distance. See alignment errors when comparing photos and aligning photos by the eyes to compare.

What about the patient's selfie?

Patients arrive with selfies and say "this is how I see myself." A selfie, taken up close, distorts the face, and the sense of self-image rests on it. This explains part of their concerns and fits the topic of mirror, selfie and photo: why patients see themselves differently. Showing the difference with a standardized photo can help calibrate the concern.

What does Harmy do with the photo?

Harmy works with one frontal photo per session, taken with the camera or chosen from the gallery. It detects the face on the device to show labeled points and lets you mark the areas. The quality and standard of the photo influence the marking and the final image. The app does not correct lens distortion. So follow the frontal photo standard described in standardized frontal photo and bad photo in Harmy: how to improve it.

How do you set up a photo corner in the office?

Standardizing does not require a studio. With a few items, any room becomes a repeatable photo spot.

1. Neutral wall. A plain, light, matte background with no pictures or reflections.
2. Floor marks. One strip of tape for the patient and another for the device, always at the same distance.
3. Tripod or support. Keeps the height and prevents shake. If you have none, rest the device on a fixed stand.
4. Diffuse frontal light. A side window does not replace frontal light. Avoid overhead light, which creates shadows under the eyes.
5. Stool or chair. So the patient always sits in the same position and at the same height.
6. Written setup. Note the distance, height and device in the clinic's protocol, so anyone on the team can repeat it.

Train the team. Whoever takes the photo needs to know the standard and why it matters. Photos taken by different people without training produce variations that compromise the whole record. A quick check before the click, such as "eyes at lens height, chin straight, mouth relaxed," solves most problems.

If the clinic works in more than one room or location, replicate the setup in each. Comparison between sessions only makes sense when the capture is the same. Finally, store photos with the date and session ID, following storing patient photos, and protect access, in line with consent and LGPD for photos (LGPD is Brazil's data protection law).

Summary

Standardize distance, height and lens. Avoid selfies and ultra-wide lenses. Repeat the standard at every session. A faithful photo is the basis of any measurement or simulation. The clinical decision belongs to the qualified professional, in line with the rules of their professional board in Brazil.