decimal value of canon lens means？

[sunmike]

I want know canon lens information,but don't use exiftool ,  I want develope php exif extension to read the lens information,
but I don't know the difference  for example
4   = Canon EF 35-105mm f/3.5-4.5 or Sigma Lens
4.1   = Sigma UC Zoom 35-135mm f/4-5.6
I read the documention link:http://www.exiftool.org/TagNames/Canon.html#LensType
Canon LensType Values 22    LensType int16s    --> Canon LensType Values
LensType is int16s,but 4.1 ? who can explain decimal value of canon lens means？

I'm sorry for my poor english

[BogdanH]

Hi,

In reality, decimal lens ID doesn't exist. Because third pary lenses (Sigma, Tokina,etc.) use the same ID values as Canon, Phil decided to put decimal point (for such cases) into documentation. That is, ID=4 means Canon lens was used, but it could also be Sigma, etc.

Bogdan

[sunmike]

@BogdanH  Thank you!