What is 50 135mm on aps c in full frame?

50-135mm on APS-C gives the view of 75-202mm on full frame.

The same view on every common format:

• Medium format (44 x 33): 95-256mm
• Full frame: 75-202mm
• APS-C (yours): 50-135mm
• APS-C (Canon): 47-127mm
• Micro Four Thirds: 38-101mm
• 1-inch: 28-75mm
• 1/1.3-inch: 21-56mm
• 1/1.7-inch: 16-44mm
• 1/2.3-inch: 13-36mm

Crop factors are by the sensor diagonal, rounded as they're usually quoted; a format with a different shape (4:3 against 3:2) frames a little differently across the width. More in the focal length converter.

Computed from the sensor sizes, not written by a model.