Boom arm length and safe load for filming deadlift 2m behind at 1.2m height

Part of our guide on mount stability during heavy vibration

Get the exact boom arm length and load rating you need to film deadlifts 2 meters behind safely with your phone and gimbal.

What boom arm length supports filming 2 m behind lifter at 1.2 m height

Filming a deadlift 2 m behind the lifter at 1.2 m height requires a boom arm length longer than the direct horizontal distance to ensure the phone clears the lifter safely. The lifter's body depth and nearby equipment can interfere if the arm is too short.

You need to consider the vertical offset of 1.2 m as well as the horizontal 2 m behind. Using Pythagoras’ theorem, the boom arm length must be at least the square root of (2² + 1.2²), approximately 2.33 m, to hold the phone so it’s 2 m back and 1.2 m high.

However, an arm this long offers no clearance to avoid the lifter’s back or the gym rack. Adding at least 0.2 m clearance brings the recommended boom arm length to about 2.5 m to avoid collisions and allow safe adjustments.

If your setup limits space or you want more maneuverability, consider a boom arm between 2.2 m and 2.5 m long. Below 2.2 m, you risk your phone or gimbal clipping the lifter or equipment; beyond 2.5 m can be cumbersome and unstable. For the detail, see our notes on hardware specs for phone mounts.

What safe load capacity is needed for iPhone 15 Pro Max plus 3-axis gimbal 1.5 m behind lifter

The iPhone 15 Pro Max weighs about 221 grams, and a typical 3-axis gimbal adds 1.2 to 1.5 kilograms. Together, your total mounted load will be roughly 1.4 to 1.7 kg.

For safety and stability, boom arms and mounts should be rated at least 50% above the combined weight to handle dynamic loads caused by vibrations, accidental knocks, or arm extension leverage.

This means the boom arm and mount you choose must safely support at least 2.5 kg to 3 kg load capacity. Choosing a boom arm rated just at your device weight risks damage or failure during filming. Before you commit to anything, it is worth looking at phone placement for full body lift.

Load ratings often depend on both static weight and arm extension length. Longer extensions reduce safe load capacity due to leverage, so check manufacturer specs carefully for 2+ meter extensions.

How to position and secure the boom arm safely for this filming setup

Position the boom arm so the phone is 2 m behind and 1.2 m high, but ensure the arm base is firmly fixed to a stable point like a gym rack or weighted stand.

Use counterweights on the arm’s opposite end to balance the phone and gimbal load, especially with extensions over 2 m. This prevents tipping or sudden drops if the mount loosens. Before you commit to anything, it is worth looking at distance for filming full body lifts.

Secure clamps and locking mechanisms at every joint. Regularly check these during filming as vibrations from the lifter can loosen connections.

Consider safety cables attached between the phone and a fixed point as a fail-safe against accidental falls.

If using a tripod or floor stand, make sure its legs spread wide enough to support the extended arm without tipping.

1. Mount the boom arm base firmly to a stable gym structure or tripod.
2. Attach counterweights appropriate for your phone and gimbal weight plus 50%.
3. Extend the boom arm to reach 2 m horizontal and 1.2 m vertical offset.
4. Lock all joints securely and test for wobble.
5. Attach a safety tether from phone mount to boom arm or base.

What boom arm length to put phone 2 m behind lifter and 1.2 m high for deadlift filming with safety

Directly answering the question: use a boom arm around 2.3 to 2.5 meters long to position your phone safely 2 meters behind a lifter at 1.2 meters height.

This length accounts for the vertical height and horizontal distance using the Pythagorean theorem plus additional clearance to avoid the lifter’s back or gym equipment.

You must verify that your chosen boom arm’s load rating supports not only the weight of your phone and gimbal combined (about 1.5 kg) but also includes at least a 50% safety margin, meaning a minimum 2.5 kg capacity.

Mount and secure the boom arm firmly with counterweights and safety tethers to avoid dangerous tipping or dropping during the deadlift movement.

How to calculate the correct boom arm load rating for your phone and gimbal setup

Start by weighing your phone and gimbal combined. For example, an iPhone 15 Pro Max plus a 3-axis gimbal typically weighs between 1.4 and 1.7 kg total.

Multiply the combined weight by 1.5 to factor in safety margin for dynamic loading and leverage effects. This gives a minimum required boom arm load rating.

Next, consider the arm extension length. Manufacturers often specify load capacity decreases as arm length increases. Check specifications for your 2.3–2.5 m arm length.

If no exact specs are available for your arm length, select the next highest load rating to be safe.

Always include additional safety measures like counterweights and locking clamps regardless of the rated capacity.

Best boom arm types and mounts for filming deadlifts safely from behind

Boom arms come in various materials and designs. Aluminum or steel alloy arms tend to provide the best balance between strength and weight for extended lengths of 2+ meters required here.

For secure mounting, use heavy-duty clamps designed for gym racks or dedicated tripod bases with wide legs and counterweights.

Telescoping arms add flexibility but may sacrifice load capacity; fixed-length or fewer-joint arms often offer more stability.

Consider boom arms that include built-in safety features like locking joints and cable management for tethers.

Magnetic mounts are unsuitable for long boom arms and heavy loads; mechanical clamps are the safest choice.

Questions people still ask

I’ve rigged multiple deadlift filming setups and know that precise boom length and load safety margin prevent costly drops.