Macro converter metadata

[krzysiu]

Hello! It's my first post, so let me introduce myself. My name is Krzysztof and I'm from Poland. I'm programmer and my passion is photography. Sorry if the following question was answered already. I did my best to find it.

Where should I write data about external hardware which isn't hidden for camera? I'm talking about macro converter. For people who aren't into photos: it's purely analog, it's an extension for lens, like magnifying glass. If it matters, I'm using Canon 50D and I'm not planning to change it (so Canon namespace is possible). I'd love to be able to write it to picture metadata. Of course I can write it anywhere, but I'm metadata beginner and maybe there's some place which is the most proper. Software compatibility is not important. As long as ExifTool can read it, it's fine for me.

The best type of field for me would be string, where I could add macro converter model. The worse and less satisfying would be integer and the worst would be boolean.

And if there's nothing recommended, where would you save it? Exif? XMP? IPTC? I'll repeat myself - compatibility doesn't matter. If Windows 7 would show it, it would be great, but I know that Windows isn't good with metadata, so it would be just a bonus for me.

Or maybe there's some field which is used to save even other external hardware? I've external timer and maybe someday I'll find use to save it, when I took some series using it. But then I'd probably want pic index and total pics, so that's another case.

I hope that I'll finish my gallery script soon and I'll add a lot of my work to the great world of open content

[Phil Harvey]

I would recommend using XMP.  If you can't find a suitable XMP tag that already exists, you can create your own.

- Phil

[StarGeek]

IMO, XMP would be the best group to add it to.  It's the most modern and flexible.

I would think the best place to add it would be as a XMP:Subject (and/or IPTC:Keywords if you like).  I would think that would be the most compatible and easiest overall.  It would show up in just about any software that deals with metadata, including Windows, where it would show up under tags.

Other options could be Description/Caption-Abstract, though if you eventually plan on writing other info about the image, that might be a conflict.  You could tack it on to the end of a tag like xmp:Lens, though that might be a bit messy if you made a mistake and ran the command twice, though there could be ways to avoid that.  Finally, you could create your own user-defined tag, say something like XMP:ExternalHardware and put the info there.  That would be the least compatible way, but it would also be unlikely to break other programs ability to use the metadata.

[krzysiu]

Thanks both of you! It's a shame that there's no standard tag for external hardware yet. For me that's very important part of photo data - filters, converters, external flash or even tripod. Heck, that's critical data, even phone lens filters are trendy now.

I don't like creating custom stuff, if it's not needed. The XMP:Lens seems to be ok, but I think that someday I'd want to add more external hardware data and it'd be much hassle - on update check every if exists, if not, then add it etc. and it wouldn't fit if I'd want to add lens unrelated hardware. So, bearing my guilt, I'll make my own tag. It will be fine for my uses, i.e. recognizing it by my gallery script and filtering photo files using exiftool.