Canon and Nikon DSLR and Mirrorless cameras and lenses have been put together as accurately as possible during assembly but will always vary in their calibration due to the manufacturing, handling and transport process.
Regardless of how carefully you handle these precision pieces of hardware over time a knock here and a knock there, plus wear and tear will reduce the focus sharpness of your optical investment.
Shooting wide open with shallow depths of field is where the variations are most noticeable. If you have ever looked at one your images and thought it was a little soft, then having your kit calibrated with Photo 74 could turn your good lens into a great lens.
Consistent, accurate and reliable focus is a must for everyone who takes their photography seriously, whether you're a hobbyist or professional.
Whatever your choice of subject the moment may never offer itself again, so make sure you capture it with perfect focus.