Why a tripod slips and how to keep its locks firm
Loose leg locks, grit in the joints, worn feet and a loose head or plate cause most tripod slips. Tighten, clean and check each part in turn to keep the camera steady.
Tripods slip for a handful of reasons, and most of them are easy to check. A leg lock, a head control or the camera plate is not holding its position, usually because a lock has loosened, grit has worked into a leg joint, the feet are sliding on a smooth floor or the camera's weight sits off-center. A few minutes of tightening, cleaning and checking usually resolves the problem.
Slipping rarely happens all at once. A leg that creeps down slowly, a head that tilts after you let go, or a camera that rotates when you touch the control all signal a part that is slightly out of tune. Dealing with these signs early helps prevent a tripod from collapsing under a camera or lens, and those parts often cost more than the tripod itself.
Tighten each leg lock the same way
Tripod legs usually have one of two types of lock. A twist lock tightens when you turn a collar or ring firmly against the leg section, while a flip lock uses a lever that clamps the section when pushed closed. For a twist lock, turn the ring until it stops, then check that the section does not slide when you lift the tripod by the leg. For a flip lock, push the lever down until it is firm, then check the tension. Many flip locks have a small adjustment ring or cap that changes how hard the lever is to close.
Work through every leg, because a tripod is only as steady as its loosest section. Extend the thicker upper sections first, since they form the strongest part of each leg. Use the thinnest lowest section only when you need the extra height. Set each section to the length you need, then make sure its lock is fully engaged, because a half-engaged lock can let a section creep under the weight of the camera. If the tripod has a center column, give it the same attention. A column raised high moves the camera's weight farther from the base, so keep it low where the shot allows and tighten its lock before you let go of the camera. Tighten each lock with similar pressure, and do not force a lever past the point where it is firm. Over-tightening can crack plastic parts or strip threads, which creates a different kind of failure later.
After a shoot, make the lock check part of the packing routine. Vibration in a car, repeated opening and closing, and heavy loads can slowly loosen locks that were tight when you set up. A quick pass before you leave the location prevents the surprise of a leg sliding during the next shot.
Clear grit and worn parts from the joints
Outdoor shoots bring sand, dust and small stones into the leg sections. Grit acts like sandpaper inside the joints, wearing both the tube surfaces and the lock parts, and it stops the lock from gripping evenly. The lowest sections are the thinnest and sit closest to the ground, so they collect the most grit. Check those sections most often. After use, collapse the legs and wipe each section with a dry cloth. If the locks can be opened, clean the threads and inner surfaces and remove loose grit with a small brush.
If the tripod has been near sea water, sand or a wet location, rinse the legs with fresh water and dry them thoroughly before storing them. Let metal parts dry completely, since trapped water can corrode the joints. Avoid soaking the whole tripod or spraying liquid into the lock mechanisms.
Check the feet as well. Rubber feet wear down on smooth floors and grip poorly on tile, polished wood and concrete. Replace worn feet with the type made for your tripod, and if your model has spikes, retract them when working indoors to protect floors. Some owners add lubricant to the joints, but check the manual first, because a grease that collects dust can cause more slipping than a dry joint.
Check the head, the plate and the load
The head is the other common source of slipping. A ball head has a friction knob that controls how easily the ball moves. Tighten it until the head holds the camera at any angle without drifting, then leave enough movement to adjust the frame. If the head has a bubble level, use it to level the camera before you lock the controls, so horizons in the frame run straight. The level shows orientation only, so a level head does not make a tripod more stable. The pan lock and tilt lock should each hold firmly when tightened. If a head slowly sinks or rotates while locked, the main lock may not be fully tightened, or the head may be worn and need service.
The camera plate and quick-release clamp work together. Attach the plate to the camera with its screw, and make sure the camera is seated firmly. Slide the plate into the clamp until it clicks, then engage the safety catch if the system has one. A plate that rotates, wobbles or pulls free usually has dirt in the clamp or a clamp that is not fully closed.
Finally, check the load. A heavy camera with a long telephoto lens creates a lever that pulls the head forward, and the head and its lock have to hold that turning force. The standard fix is to mount the lens by its tripod collar or foot rather than by the camera body. Clamping that collar in the head places the mounting point near the lens's center of gravity, so the load balances over the head instead of pulling it forward. Keep the weight centered over the legs, and check the weight rating in the tripod's specifications before you mount a heavy lens. A tripod will not stay stable under a load beyond that rating, even when every lock is tight. Footing matters as well: set the feet on firm, level ground, because soft sand, loose gravel or a sloped surface lets the legs shift under the weight.
A short check of the legs, the head and the load before each shoot takes only a few minutes, and it catches most of the problems described above before the camera moves.