How to take physique progress photos an AI can actually grade

1. Same spot, same light, same time of day

Progress is a difference between two photos, so anything that differs between them and is not you becomes noise. Pick one wall, one lamp, one time of day (first thing in the morning is easiest to repeat), and write it down. When we re-tested our own grader with its settings pinned, every re-saved copy of the same photo (darker, brighter or heavily compressed) came back one step lower on shoulders, every time. Keep the original file, not a screenshot or a re-saved copy of it.

2. Whole body in the frame, phone at chest height

• Six to ten feet (2 to 3 m) back, phone propped at roughly chest height, level, not tilted up from the floor.
• Head to feet in the frame with a little air above and below. A photo cropped at the knees cannot grade calves; cropped at the hips it cannot grade legs at all.
• Use the timer or a friend. A mirror selfie puts your arm across your torso and a phone over your face.
• Plain background if you can. The grader is looking at edges.

3. The angles, and what each one shows

One front photo is enough to start; that is how FlexScan's first scan works. If you want back and glutes graded rather than marked "Not visible", add a back photo. Keep the same set of angles every time you re-shoot, or you are comparing different things.

4. Relaxed or flexed? Pick one and keep it

A flexed pose shows separation and peak that a relaxed stance hides, which is why bodybuilding check-ins use both. A relaxed stance is easier to repeat exactly, which is why FlexScan asks for it. Either is fine for tracking. Switching between them is not: a flexed front next to a relaxed front reads as progress that did not happen.

5. Clothing

Whatever is covered does not get graded. Shorts and no shirt, or fitted training clothes, in the same color each time. Loose fabric hides the exact edges the grader needs.

6. The four photos that come back "Not visible"

• Backlit: a window behind you turns you into a silhouette. Light should hit you from the front or the side.
• Cropped: no feet, no calves. No hips, no legs.
• Arm across the body: the mirror-selfie pose hides core and one side of the chest.
• A screenshot or a chat-app forward instead of the original: compression eats the detail that separates a B+ from an A-.

7. How often

Every two to four weeks. Muscle changes slower than water and lighting do, and a grader that is honest about its own noise will not report a one-step change as progress anyway. Weigh in more often if you like; photograph less often, but identically.