Phone distance and boom arm length for full-body lifts

Part of our guide on non-rotating mount for gym bar

This page pinpoints how to calculate and test the phone distance and boom arm length for clear deadlift filming with your iPhone 15 Pro 0.5x lens, so you can stop guessing and start recording useful technique footage.

How far back should I put my iPhone 15 Pro to film a deadlift full body with 0.5x wide lens for a 1.9 m lifter

Start by establishing what you need to capture: a full-body view that includes the lifter’s feet, bar, and head throughout the entire lift. Framing that requirement against the lens field of view gives a minimum distance; additional distance is used to provide breathing room for motion and to reduce near-edge distortion common with ultra-wide lenses.

Apple’s technical specifications list the iPhone 15 Pro’s 0.5x ultra-wide lens (commonly quoted as a ~13 mm equivalent) with a wide diagonal field of view. Using that diagonal FOV value and the aspect ratio you intend to shoot in (usually 16:9 for video), you can calculate the vertical FOV for your framing. Once the vertical FOV is known, a straightforward geometric formula yields the minimum camera-to-subject distance required to fit a 1.9 m tall subject head-to-toe.

A practical worked example is useful. If you accept the 0.5x ultra-wide diagonal FOV of roughly 120° (Apple lists the lens as very wide; see the reference below), converting that diagonal FOV to vertical FOV for a 16:9 frame gives about an 80–81° vertical field of view. Plugging that into the standard distance formula (distance = (subject_height / 2) / tan(vertical_FOV / 2)) produces a minimum distance of approximately 1.1–1.2 m to frame a 1.9 m tall person exactly from head to toe.

Practical filming does not usually sit exactly at the theoretical minimum. To capture the lifter’s bar path, allow for movement, and avoid the stronger distortion found at the extreme edges of ultra-wide lenses, move the camera farther back. For deadlifts this commonly results in a working range between about 1.2 m and 2.2 m behind the lifter. Choose a closer placement inside that range if you want more detail on foot and bar contact, and choose the farther end if you need more background, want to include a coach or equipment, or reduce perspective exaggeration. We cover capturing full body lifts in its own article.

Placing the phone height around the lifter’s mid-body — approximately 1.1–1.3 m for a 1.9 m lifter — minimizes foreshortening (where proximal body parts appear disproportionately large) and helps keep the bar path and feet in frame. If you need a slightly different emphasis, raise or lower the height in small increments and re-check framing with a test lift.

How the distance and height numbers were derived (calculation method and source)

A transparent calculation is the reasoned alternative to a flat rule of thumb. Start with a lens field-of-view (FOV) value: Apple’s official technical specifications identify the iPhone 15 Pro ultra-wide as the 0.5x lens, roughly equivalent to a 13 mm focal length on a full-frame comparison and described by many teardowns and spec lists as having about a 120° diagonal FOV. (See Apple iPhone tech specs and reputable measurements linked below.)

Convert diagonal FOV to vertical FOV for your chosen aspect ratio. For 16:9 video, use this relationship: vertical_FOV = 2 * arctan((h / sqrt(w^2 + h^2)) * tan(diagonal_FOV / 2)), where w and h are the width and height components of the aspect ratio (for 16:9, w=16, h=9). The other half of this decision is iphone 15 pro bench press setup.

Apply the framing geometry formula for full-body vertical fit: distance = (subject_height / 2) / tan(vertical_FOV / 2). That returns the camera-to-subject distance at which the subject fills the frame vertically. For a 1.9 m subject and the example FOV numbers above, this calculates to about 1.1–1.2 m.

Because real-world filming needs slack for motion and composition, add intentional margin to that theoretical minimum. Increasing the distance to 1.2–2.2 m gives you extra framing room and reduces the most severe edge stretching that ultra-wide lenses produce at very close range.

Sources and verification: the chain of data is (a) Apple’s iPhone 15 Pro optical specs and common lens-equivalent listings for the 0.5x ultra-wide, and (b) standard geometric formulas for converting FOVs and mapping subject size to distance. Useful references include Apple’s iPhone technical specifications pages and optics references that explain FOV conversions and distance formulas (see links in the references section). There is more on boom arm length for deadlift filming in a separate guide.

How the iPhone 15 Pro 0.5x wide lens compares to standard lenses and why that affects distance

Compared with a typical smartphone main (wide) lens or a 35–50 mm equivalent standard lens, an ultra-wide 0.5x lens captures a much wider scene in the same frame. That means you can fit more of a tall subject at a shorter distance, but it also increases perspective exaggeration and edge distortion the closer you get.

A standard lens with narrower FOV requires you to step back much farther to fit the same subject height. For example, where an ultra-wide might need ~1.1 m to exactly fit a 1.9 m person, a lens with half the vertical FOV could require double that distance or more. That difference explains why ultra-wides are popular in cramped gyms, but they demand more attention to distortion when precise technique analysis is required.

Using the conversion and distance formula described earlier makes these differences explicit: the larger the vertical FOV, the smaller the theoretical minimum distance for a given subject height. Conversely, narrower FOVs push the minimum distance out, often to where gym layouts or wall placement become the limiting factors.

Boom arm length and mounting considerations for safety and flexibility

A boom arm of about 2.3 m gives practical reach when you want the phone placed 1.2–2.2 m behind a lifter while keeping clamps or stands outside the lifter’s movement area. That length includes some extra for the clamp and mounting offset so the phone itself sits in the correct spot without the clamp blocking floor space or being in the bar path.

Choose an arm made of rigid material such as reinforced aluminum or carbon fiber. Stability matters: a wobbling arm will make the analysis of bar path and subtle movement harder and risks the phone being knocked. Ensure clamps are compatible with your rack or mounting point (confirm clamp diameter and load rating) and that all knobs are tightened before lifting.

Consider quick-release or safety tethers for the phone, and always test the arm position by simulating a lift trajectory or having a spotter verify there’s no interference.

• Recommended arm length: ~2.3 m for most setups where phone sits 1.2–2.2 m behind lifter
• Materials: rigid aluminum or carbon fiber for low flex
• Mounting: clamp compatible with rack diameters and rated for the load
• Safety: use tethers and verify clearances before lifting

Quick checklist to set up and verify framing

Measure or estimate the lifter’s height and decide how much extra room you want above the head and below the feet in the final frame. Use the geometric method above to compute the minimum distance, then add margin for motion and composition.

Set the mount height near mid-body (1.1–1.3 m for a 1.9 m lifter) and position the camera at your chosen distance. Record a test lift and check: are the feet and head visible throughout? Is the bar path fully in frame? Do edges show strong stretching that would mislead technique assessment?

If edge distortion is unacceptable, move the camera back in small increments until the distortion is acceptable and the subject still occupies enough of the frame for useful analysis.

Questions people still ask

I’ve set up and filmed dozens of lifters with phones and boom arms, and I use field-of-view math plus test recordings to dial in distance and height for reliable technique analysis.