"Video chimney inspections can spot defects anywhere along the entire length of the chimney, and they are the only way to examine a chimney that has any changes in direction."You can't tell a chimney is having problems just with a quick glance. A Level II video inspection of your chimney will go up the whole length of the chimney, and spot any problems that are plaguing it, and may help to prevent potential issues.
Read the entire article: "Chimney Video Inspections and High-Tech Chimney Sweeps."