The cameras seem to be special cameras for close up views. Technically this is likely a simple CCTV camera with a slighly non standard lens, or possibly even just more normal lense with extension tube to get a closer focuss.
They key to getting good close up pictures is to have a stable mechanical setup and penty of light, so you can use a relatively small apperture and small, but high pixel density chip. So in principle this does not have to be an expensive camera, as small aperature and small chip is what you get from cheap cam (e.g. phone, USB microscope, webcam). So no expensive large lense or large sensor is needed.