This explanation uses Photoshop Elements 2.0 as an example to describe the procedures for downloading images from the camera and transferring. If you are using other application, refer to the User' s Manuals provided with your software for information on setting up and using TWAIN devices.
To accommodate the sensor size of APS-C DSLR cameras, the image circle (the circular area in the image plane formed by the cone of light transmitted through the lens) has been made smaller. To accommodate the smaller quick-return lens of the cameras, the back focus (the distance from the rear element of the lens and the sensor) is shortened further (short back focus) than that of the regular EF lenses. Reference:
To accommodate the sensor size of APS-C DSLR cameras, the image circle (the circular area in the image plane formed by the cone of light transmitted through the lens) has been made smaller. To accommodate the smaller quick-return lens of the cameras, the back focus (the distance from the rear element of the lens and the sensor) is shortened further (short back focus) than that of the regular EF lenses.
