You asked
What is 58mm f2 8 on canon aps c in full frame?
58mm on APS-C (Canon) gives the view of 93mm on full frame. For the same depth of field, f/2.8 there behaves like about f/4.5 on full frame. Exposure doesn't change: f/2.8 gives the same brightness on any sensor.
The same view on every common format:
- Medium format (44 x 33): 117mm at about f/5.7 for the same depth of field
- Full frame: 93mm at about f/4.5 for the same depth of field
- APS-C: 62mm at about f/3 for the same depth of field
- APS-C (Canon) (yours): 58mm at about f/2.8 for the same depth of field
- Micro Four Thirds: 46mm at about f/2.2 for the same depth of field
- 1-inch: 34mm at about f/1.7 for the same depth of field
- 1/1.3-inch: 26mm at about f/1.2 for the same depth of field
- 1/1.7-inch: 20mm at about f/1 for the same depth of field
- 1/2.3-inch: 17mm at about f/0.8 for the same depth of field
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.