A spy camera can be any sort of camera a meant to take pictures or video of a person or scene without their knowledge. Traditionally, the term spy camera was used for cameras actually used within the context of espionage, as in small cameras carried during the Cold War to take photographs of plans, building, or troops. In modern usage, however, it more often refers to a small, easily- concealable photo or video camera usb that can be purchased by consumers for their own purposes.
If you are  looking to buy a spy camera that is actually intended for espionage, the types of things to look out for are quite different. An actual historical spy camera mini can be quite expensive, but they do frequently come up for auction, often bundled with other remnants of various wars. Modern spy cameras used by the intelligence computer are incredibly sophisticated, able to fit in very small spaces, often with a great deal of on- board storage capacity, or else with a short-range or long-range wireless transmission device. This type of spy camera is generally inaccessible to the civilian population, and where available they are generally cost prohibitive.
If you are looking for something to use as a spy camera that will be more affordable, the first step to choosing the ideal is to figure out exactly what you?l be using it for, and where you can potentially hide it, such as    . The smaller the camera, at a comparable price point, the worse the image quality, so you?l also need to decide how important image fidelity is to you. You?l also need to decide whether you are only interested in still photographs, or whether video is an important feature.
A very small video spy camera  will take videos that will show the general movement of a situation, and a broad idea of what people involved look like, but the resolution may be too poor to really see facial feature or discern small details. For this, a larger spy camera I generally needed, which will make hiding it much more difficult. In places where space is not an issue, as in a room where space can be made behind a wall with only a small opening for the lens, this may not be an issue, but in  spaces where there is nowhere to put a larger camera , quality may have to be sacrificed.
Many types of spy camera come pre-built with their own camouflage these days. For example, one popular type of spy camera comes installed in a teddy bear. This is meant to either spy on nannies or other workers who interact with small children, or is meant to be given as a gift to a child so that one can watch in on them. Generally these operate with memory included in the device that must be downloaded to a computer, but some come with wireless capabilities. Another type of pre-camouflaged spy camera looks like a DVD player, or other working technology device, but while operating also records what is happening in the room with it.