Camera problems

After the trip to Oman when all the photogrpahs were overexposed. I decided to test the lenses and camera this morning.

The left column is over exposed by one stop
The centre column is is 'correct' exposure
The right column is under exposed by one stop

The top row is my 55mm lens at 18mm setting
The 2nd row is my 135mm lens at 28mm setting
The 3rd row is my 300mm lens at 70mm setting
The 4th row is my 135mm lens at 135mm setting
The bottom row is my 300mm lens at 300mm setting

Conclusion
My 28-135 lens is broken, and the others can probably benifit from under exposing by about half a stop