Drain (inspection) cameras are known as borescopes, but even experienced plumbers like myself don’t call it that. The latter is a more technical term for an instrument that is used in all kinds of industries and applications. A drain (inspection) camera allows you to view certain places where it’s physically impossible for a human being to fit. Although when it comes to sewer inspection, there are two types of cameras, I’ve come to realise that there are multiple factors which affect the quality and effectiveness of both.
These are portable and small, allowing you to carry them with you wherever you go. The camera cable of a handheld inspection camera is directly connected to the device, so you can use it when needed without having to plug it into a separate module. I personally prefer to use the handheld camera as it’s been with me since the beginning and it saves me a lot of time when trying to wheel in the larger reel camera.
A reel inspection camera is a must when you need to take a look at more complex and lengthier pipelines. Again, this is not my favourite solution but sometimes you’ve got to bring out the big guns. These have wheels and a lot of cable which is attached to a module with a screen on it and usually a keyboard. A reel camera gives you a lot more features to work with but also a lot more to deal with when you have to go upstairs.
What to Look For
The resolution of inspection cameras is usually 320 x 240 (QVGA) and 640 x 480 (VGA). These may seem like low resolutions for a camera sensor, especially in today’s world of high-end megapixel cameras capable of shooting 4K videos, but in a small device they are more than enough. In order to get a clearer image, you need more light. I’ve found out that the less pixels there are (lower resolution) in a sensor, the bigger said pixels will be thus allowing for more light to enter. So, in this case, it’s better to have a camera with a lower resolution. Lately I’ve been able to find drain cameras that have VGA sensors with more pixels in the same form factor thanks to new substrate materials and new sensor technology.
When I search for small objects in tiny corners, a camera with a fixed or close range focal length works best. For general use, an inspection camera with a 20 mm to infinity focal length is going to work just fine. I mainly use them to view larger objects in a bigger space. You can adjust the focal distance when you want to see close objects but this will reduce the camera’s depth of field and anything beyond 1mm is going to be out of focus. The focal length should be based on the type of work you do.
The cable you ought to use also depends on the type of work you are doing. When I make sewer line inspections, a camera with a cable at least 3 m long is necessary – believe me I learned that the hard way. If you go for a thinner cable, it will be easier to navigate through tight spaces. I’ve also found some cameras that have an adjustable cable slot – this allows you to switch to the cable that suits the situation the most.
If you are going to be working mainly in households I recommend you go with a drain camera that uses rechargeable batteries. If not, go with cameras that use disposable ones as you never know if electricity is going to be readily available. This way you can just swap out the battery without having to rely on the grid. While a rechargeable battery is more economical, it shouldn’t be something you rely on when doing work where electricity is not available.
Recording & Memory
While this wasn’t very important when I was starting out, nowadays, being capable to document results is a crucial thing for every professional. DIY applications may not require this function but if you are serious in this endeavour, I recommend you get a drain (inspection) camera with recording capabilities. This way you can justify extra expenses or share information with colleagues – a small camera most likely won’t have this capability.
In case you choose a camera that has recording capabilities, then you’ll almost always need additional memory. In order to store the files and send them to clients and co-workers you’ll need sufficient internal or external memory. If the drain camera you are getting doesn’t have enough internal memory, then an SD card is going to be needed. Make sure the system has an SD card slot.