Canon focusing riddle

[shutterman]

My neighbor has a Canon Rebel digital camera. Kit lens and ring flash (he is a orthodontist and needs good before and after teeth pictures).

Anyway, he puts the camera on macro program mode (the Flower picture on the dial) and takes the close up picture with the ring flash. Then he has the patients step back and takes a profile and full face shot.

At this point, the camera will not focus on the face. Switching to other modes - either the portrait or landscape or program will not work either.

Any ideas? I use Nikon so I am not much help to him.

Please help!
Thanks,
Wes

[Lionheart]

My neighbor has a Canon Rebel digital camera. Kit lens and ring flash (he is a orthodontist and needs good before and after teeth pictures).

Anyway, he puts the camera on macro program mode (the Flower picture on the dial) and takes the close up picture with the ring flash. Then he has the patients step back and takes a profile and full face shot.

At this point, the camera will not focus on the face. Switching to other modes - either the portrait or landscape or program will not work either.

Any ideas? I use Nikon so I am not much help to him.

Please help!
Thanks,
Wes

Hi Wes:
I'm a dentist who uses digital canons in my office pretty extensively for before/after,photos for our reconstruction and orthodontic patients.
Set up needs to be a dedicated macro lens (we use the EF 100mm f2.8 USM macro lens) and ringlight (Canon MR-14EX or MT-24EX).
Your friend needs to set the camera to manual, put the flash (I'm assuming it is a canon mr-14ex) on ettl with high speed sync enabled. The lens can be set to AF or MF, works best with the center AF point for face shots and retracted smile shots, and one of the side AF points (point it over a bicuspid) for the mirrored arch shots.The manual settings need to be 1/100 sec or faster (assuming he is using a 100mm macro) and he needs to set aperture to f16 to f20, + 1/2 to 2/3 stop overexposure on the flash (canon tends to underexpose macro by that much-happens on all my digi canons), when taking up close photos of the teeth. When taking the head shots (smile, relaxed and profile), set to f2.8 to f4 and again shutter stays the same. Pm me or email me and let me know how that went or didnt ;)