Subject Distance in EXIF Data

Just looking at the exif data from our recent vacation pictures and noticed that some of them have the subject distance in the exif data and others do not.

Is there a certain exposure program or setting that determines whether this info is saved? I haven't been able to find any information regarding this so far.

Thanks for any help or insight.

I suspect that it differs by lens. Check again and I suspect you'll find that the same lens always provides distance info.

I though that at may be the reason at first, but it happens with my kit lens and 70-200L. Only a fraction of the pictures contain "max aperature value" and "subject distance" in the exif data. After having my T1i returned to Canon twice for focus issues it makes me wonder if there may still be an issue.


"SORTED"... Using Opanda IExif to view the exif data the max aperature and subject distance is not shown. Once I have touched them up using using PS CS5 it is listed.