You asked
What is 50 140mm on aps c in full frame?
50-140mm on APS-C gives the view of 75-210mm on full frame.
The same view on every common format:
- Medium format (44 x 33): 95-266mm
- Full frame: 75-210mm
- APS-C (yours): 50-140mm
- APS-C (Canon): 47-131mm
- Micro Four Thirds: 38-105mm
- 1-inch: 28-78mm
- 1/1.3-inch: 21-58mm
- 1/1.7-inch: 16-46mm
- 1/2.3-inch: 13-38mm
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.