Inverted center column in a photography tripod and counterbalance for macro overhead shooting with a horizontal center column

1. Physical limit of minimum working height: Why must the bottom bracket be inverted?

Even if a conventional professional tripod has its three legs opened to their maximum position and laid flat on the ground, due to the protruding obstruction between the central cast aluminum base and the bottom of the upright central axis, the minimum height of the head from the ground is still 25cm ~ 40cm:

• Despair from a microscopic perspective: When photographing a tiny wild mushroom on the ground, insects crawling on the ground, or dewdrops on grass blades in the morning, the 30cm camera position is unacceptable and condescending, and cannot capture the grand depth of the microscopic world at a level level;
• Breaking point of Inverted Column:
• Unscrew the anti-decoupling screw at the bottom of the bottom bracket, pull out the entire bottom bracket and insert it backwards from the bottom of the base to lock it;
• The pan/tilt and camera are hung upside down directly under the ‘triangular tent’ constructed of the three legs of the tripod;
• Real zero distance to the ground: The front lens group can be pushed vertically downward or horizontally to achieve 0 distance from the ground (only a few centimeters from the ground), completely breaking the physical shackles of camera height!

2. Difficulties in operating the fuselage in an inverted position after the central axis is inverted and techniques to solve the problem

Although the inverted central axis achieves an ultra-low camera position, it also brings an extremely anti-human side reaction - The entire camera is turned upside down (Inverted Camera):

1. Viewfinder and screen inverted dizziness:

• The viewfinder is completely upside down, and the operation direction is completely contrary to intuition;
• Modern camera flip-screen relief: Rotate the screen 180° sideways or turn on the "screen auto-rotation" in the camera to return the display to the forward direction; use the mobile App Wi-Fi wireless real-time image transmission monitoring, stand straight and touch the focus on the phone screen to release the shutter, and say goodbye to the awkward situation of lying in the mud.

2. The extremely low center of gravity of the body brings ultimate wind resistance and anti-shake:

• Principle of a pendulum in physics: The center of gravity of an upside-down system suspended on the vertical line of gravity of a tripod is much lower than the top of a conventional tripod; its wind resistance and stability are several times stronger than conventional high-position shooting.

3. Overturning moment balance of 90-degree horizontal axis (Transverse Column) overhead shot

In food photography, unboxing reviews, and handicraft remakes, the camera needs to be shot directly below the table at an absolutely vertical 90-degree angle (Top-Down Flat Lay):

• Conventional tripod leg penetration disaster: If you shoot directly downward, the three open legs will inevitably appear in the field of view;
• Cantilever extension of the horizontal central axis: The central axis is rotated 90 degrees and extends horizontally by 30cm~60cm. The camera is suspended directly above the center of the table, completely avoiding the shadow of the leg tubes and the field of view;
• Dangerous Toppling Moment:
• When the camera and telephoto lens extend 50cm forward, the 2kg mass of the entire camera generates a huge forward overturning moment of up to (10,\text{N}\cdot\text{m});
• Once the center of gravity exceeds the edge of the tripod's grounded polygon, the entire system will flip forward in milliseconds, and the camera lens worth tens of thousands of dollars will be vertically smashed onto the tabletop and shattered to pieces!

4. The iron rule for safe operation of the horizontal center axis and the configuration of counterweight sandbags

Strict operating regulations to prevent overturning accidents:

1. Align With One Leg:

• When unfolding the tripod, you must make sure that the positive direction in which the horizontal central axis extends is absolutely in the same direction and parallel to the grounding direction of one of the main support legs**!
• This leg acts as an indestructible supporting front arm; do not let the bottom bracket poke into the void between the two legs.

2. Rear cantilever counterweight bag:

• A metal load-bearing ring is usually reserved at the rear end of the horizontal bottom bracket;
• A photography weight sandbag (or a kettle filled with water) must be hung at the rear end that is absolutely equal to the weight of the front end camera equipment;
• Establish an absolute balance of torque like a scale beam to ensure that the system will not dive out of control when loosening the horizontal locking knob to fine-tune the composition.

3. Macro Rail combination: When taking macro shots with the central axis horizontally positioned, the front and rear focus depth of field is extremely narrow. Do not frequently move the heavy tripod. Install a macro two-way gear moving guide rail between the central axis gimbal and the camera to smoothly advance the focus at the millimeter level.

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