Not so visible in photos because of the way the sun hits the roof but very visible by naked eye. Enough for my neighbors to stop by to ask me what's wrong. I had the new roof installed 2 weeks ago and the dipping effect was visible from first day. I spoke to the company that installed the roof and after sending over one of their production managers the told me that the job was done correct but my plywood under the shingles has buckled. I told them as we signed the contract that any damaged plywood can be replaced at my cost, but they say the plywood was not damaged only warped. The house is 16 years old. I have labor warranty with company. What should I do?