ExifTool Forum

General => Metadata => Topic started by: lks on November 20, 2010, 02:41:09 PM

Title: Sigma 70-300mm f/4-5.6 APO DG Macro for Canon Cameras
Post by: lks on November 20, 2010, 02:41:09 PM
This lens is not in the exiftool list of lenses for Canon lenses, but it does exist, and is different from the Sigma 70-300mm f/4-5.6 DG Macro, but without the APO designator.

Should this be referred to internally as

8.3 = Sigma 70-300mm f/4-5.6 APO DG Macro

Presumably this duplication also occurs for the other mounts, but I only have the Canon lens mount variety.
Title: Re: Sigma 70-300mm f/4-5.6 APO DG Macro for Canon Cameras
Post by: Phil Harvey on November 20, 2010, 03:01:32 PM
Thanks for this.  Unfortunately since these two lenses have exactly the same focal range, aperture range and lens ID there is no way to differentiate them.  In this case I don't usually add another entry, but I could think about setting the entry to

    8.1 => 'Sigma 70-300mm f/4-5.6 [APO] DG Macro',

to indicate that the lens may or may not be the APO version.  I have done this in the past for things like version II of a lens, but haven't done it for APO yet.  My worry is that I don't want to confuse people who have the non-APO version.

- Phil
Title: Re: Sigma 70-300mm f/4-5.6 APO DG Macro for Canon Cameras
Post by: lks on November 20, 2010, 03:13:33 PM
That seems like a good solution.  But isn't there a user variable that you can use to disambiguate different lenses?  In that case, is there a way to have both listings?
Title: Re: Sigma 70-300mm f/4-5.6 APO DG Macro for Canon Cameras
Post by: Phil Harvey on November 20, 2010, 06:01:24 PM
Yes, there is a user-defined lens list, but I don't think many people take advantage of this.  I'll just add "[APO]" for now.

- Phil