A sewer camera, or drain camera as it is sometimes called, is a remarkable tool for inspecting any clogged drain, sewer line, or for proving to your potty-training child that there really are no such things as sewer monsters.
See? No sewer monsters, just drain blockage
Sewer cameras are useful for home use on just about any drain (i.e. toilet, sink) because they provide you with an in-depth look at what's really causing buildup in your drain. The way a sewer camera works is with a coil of rubber-enveloped (or Kevlar) reel that holds onto the basic camera that is small enough to fit inside the drain.
You send the weighted camera on down the drain in question, holding onto the reel from the other side. As it moves down the drain, the camera records what it sees, sending it back up the line via a transmitter to an LCD monitor that you can watch.
When you find what is blocking the drain, you then verify the length of reel you've used, which helps you assess the problem further. If the blockage is far enough down the drain, you may need to call in a plumber to help you out the rest of the way. If it's still relatively close, it may be easier to shut off the water to the toilet, remove the toilet from the floor, and fish out the clog.
Help! When you really need a sewer camera
You really only need a sewer camera if you have exhausted all other efforts to solve the blockage in your drain. Other efforts might include liquid drain cleaners, using a high-quality drain auger, and using a good old-fashioned plunger to try and loosen the blockage. It should be a last resort because a decent sewer camera costs well over $1,000.
Sometimes a clogged drain is no fault of your own, and actually falls to the city's responsibility. When that is the case, the city will use its own sewer camera equipment to assess the situation. If the utility employee finds that the problem is indeed in your own sewer line and not the main city line, it will be your task to fix it yourself or find a plumber. Either way, make sure when you buy your home that you shop around for good homeowner's insurance and find insurance that covers the cost of sewer damage, otherwise you might have to pay for it yourself, as is the case in cities like Oklahoma City.
Any drain clog is a headache, with the slow draining or pooling water that makes your life miserable. Save yourself the aspirin by looking at hardware, plumbing, and home renovation supply stores for a durable sewer camera.