Photographers know that an SLR camera lens is very expensive. Although the digital camera has changed the paradigm somewhat, one can still say that the lens is more expensive than the camera itself.
Canon has posted an informative video on how a Canon 500mm f/4.0 IS lens is constructed from beginning to end. After watching the video and seeing the labor involved to put one together, I can now see why they charge so much for the lens which typically is priced around $5,500.
One advantage a lens has over digital SLR camera these days is that a lens depreciates at a much slower rate than a camera. Digital cameras are like computers. You can buy a $4,000 camera and in two years time it will be worth $2,000 (or less). However a good $6,000 lens in 10 years could still fetch $3,000.
