Impossible DOF

This is a picture that falls under my category of 'impossible depth of field'. It's a composite of a brown pelican and Kicker Rock in the Galapagos Islands. To have this kind of depth of field in which a bird is so close to the camera position while the background is significantly filing a large portion of the frame is not possible given the limitations of our optics. So, I made it happen using Photoshop. Both images were taken with film using a Mamiya RZ 67 and then scanned with an Imacon scanner. I used two different lenses for the subjects, which in this case is OK, but note that the lighting on both the bird and the seascape is the same. The fastest shutter speed on the Mamiya RZ was 1/400, which is what I used, and the only reason the pelican is sharp is because it's such a slow flying bird.