When mounting lenses via a teleconverter like the Canon 2x, does the EXIF metadata record this information somehow? Will the recorded focal length be adjusted by the camera or the extender? Is there a metadata flag that indicates the presence of the extender during shooting?
When I use a third party teleconverter with a Canon lens, the EXIF records the lens only in the Lens field, but the actual Av and Focal Length are correctly recorded.
The EXIF info below is from a shot taken at maximum aperture and focal length of an EF 70-200mm f/2.8 L IS II + Kenko C-AF 2X Teleplus Pro 300. As you can see the aperture is recorded as f/5.6 and the focal length as 400mm.
When a Canon extender is used, the EXIF data includes the extender in the lens data.
Indeed the EXIF data records the use of a teleconverter. see the attached picture.
Here is a screenshot of the EXIF data of a photo as displayed by Apple Aperture. The labels are in German, but the values speak for themselves.
The picture was taken using a 200mm lens with the Canon 1.4x teleconverter (II), the resulting focal length of 280mm is recorded.