Dear arm.indiana,
I have two lenses, the Canon EF-S 17-55 f/2.8 IS and the Canon EF 70-300 f/4-5.6 IS USM. (I started out with the EF-S 17-85 f/4-5.6 IS USM, which I traded in, along with a chunk of change, to get the 17-55 f/2.8 IS).
The only lens of mine listed in the table at Magic Lantern that you sent me to is the 70-300, which says it sends Focus Distance.
The table at Magic Lantern sources its info about the 70-300 to DPReview.com, which turned out to be their news story covering Canon's press release for that lens, so I searched there for the same thing for my main lens, the EF-S 17-55 f/2.8. The story there about the EF-S 17-55 f/2.8 says that lens also sends distance information. (
http://www.dpreview.com/news/0602/06022113canonefs1755f28g.asp)
However, I've looked at the EXIF listings for the RAW files of shots I've taken with both of those lenses on my XTi. In Adobe Bridge the "Subject Distance" field is blank. In DPP, the Shooting Distance is "<!>" (for "I haven't a clue!")
The problem isn't that my lenses don't send the information - they do - but that the camera body isn't writing the distance in the EXIF data.
By the way, the page at Magic Lantern points at the bottom to
http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/Canon.html which lists which tags are written out by all Canon EOS models since the 450D. (Pity they don't include the 400D!) All but the 60D are listed as writing Focus Distance. (I don't think the 60D table is complete, since it's tiny compared to the others - it is a new camera, after all.)
So my request stands: Please look into making the 400D / XTi write the focus distance into the EXIF data. Built into Canon's Digital Photo Professional RAW file converter and photo editor that comes with their RAW-capable cameras is profile-based lens aberration correction with profiles for all of their lenses and RAW-capable cameras. DPP can print directly or output JPEGs or 8 or 16 bit TIFFs, which can then be brought into Photoshop. It essentially takes the place of Adobe Camera RAW, providing most of its functions, including color adjustment, rotation, cropping, sharpening, and even noise reduction.
With shots that have full EXIF data, DPP can automatically correct pincushion/barrel distortion, corner light fall-off, and chromatic aberration, based on Canon's knowledge of how its equipment behaves. (Each correction can be turned on independently, and there's an amount slider for each of them if you think it's doing too much.)
If the distance isn't in the EXIF data, you can input the distance with a slider -
which gives no indication of what value you're setting it to except for an infinity symbol at one end!
That's why I'd like to have my XTi made to write the distance lenses
do tell it into the EXIF.
