Coca~Cola 12 ounce can, 135 f/2.8 AiS, and 105 f/2.5 AiS,showing overall length and size with the 135 AiS lens focused at infinity, but the 105 AiS focused at its minimum focusing distance. The two lenses are almost the same size when the shorter one is set to MFD,so you can compare the size of your 135mm f/2.8 Ai lens by looking at your 105 AiS...I hope this gives you an idea of the size comparison, dude! I am happy to do this comparison for you.