# EOS-M EXIF Screwup?



## FunPhotons (Jul 22, 2013)

If you have the EOS-M with the *18-55* lens take a look at the lens EXIF information in a JPG shot. Do you see the following?

Lens ID: 4,143
Lens Info: 18, 55, 0, 0
Lens Model: *Canon EF-M 22mm f/2 STM*


What the hell? The Lens Info seems to tell the focal range, but did they program these with the wrong Lens Model information!?


----------



## bchernicoff (Jul 22, 2013)

I don't have this camera, so I can't repeat your test, but I wanted to ask what program you are using to view this EXIF info? Lens model info isn't saved as a text string like "Canon EF-M 22mm f/2 STM".

Edit: somehow the end of my comment was cut off. What I meant to say was that the Lens ID represents the lens model and it's the job of the program reading the Lens ID to lookup what lens name it maps to.


----------



## privatebydesign (Jul 22, 2013)

I don't know what your Lens Info is, but why dies it have 0,0 at the end?

Anyway, here is the EXIF from an EOS-M and 18-55 via EXIF Viewer.


----------



## brianboru (Jul 22, 2013)

Examined in Photoshop CS6 things seem to be kosher: 

File->"File Info"->"Raw Data" says this against a fresh JPEG: 


```
<rdf:Description rdf:about=""
            xmlns:aux="http://ns.adobe.com/exif/1.0/aux/">
         <aux:SerialNumber>03215220xxxx</aux:SerialNumber>
         <aux:LensInfo>18/1 55/1 0/0 0/0</aux:LensInfo>
         <aux:Lens>EF-M18-55mm f/3.5-5.6 IS STM</aux:Lens>
         <aux:LensID>4143</aux:LensID>
         <aux:LensSerialNumber>0000008xxx</aux:LensSerialNumber>
         <aux:ImageNumber>0</aux:ImageNumber>
         <aux:ApproximateFocusDistance>144/100</aux:ApproximateFocusDistance>
         <aux:FlashCompensation>0/1</aux:FlashCompensation>
         <aux:Firmware>2.0.2</aux:Firmware>
      </rdf:Description>
```

And "EXIF Viewer" says:


> Lens Specification = 18-55mm F0-0
> Lens Model = EF-M18-55mm f/3.5-5.6 IS STM
> Lens Serial Number = 0000008xxx


----------



## neuroanatomist (Jul 22, 2013)

Flickr shows the correct lens in Cameralab's sample images, e.g. http://www.flickr.com/photos/cameralabs/8204297848/#meta/.

So I'd say it your software that's wrong...


----------



## FunPhotons (Jul 22, 2013)

Ah, I'm viewing it in OS X Preview. I'll try looking at it using something else. Presumably the problem is in the Apple RAW library. 


So this is interesting, what is actually stored in the EXIF - a number indicating the lens?


----------



## neuroanatomist (Jul 22, 2013)

FunPhotons said:


> Ah, I'm viewing it in OS X Preview. I'll try looking at it using something else. Presumably the problem is in the Apple RAW library.
> 
> So this is interesting, what is actually stored in the EXIF - a number indicating the lens?



Yep, it's Apple's problem. I see it, too, on a sample image downloaded from canon.jp - both in Preview and Aperture. I've submitted a bug report to Apple.

FWIW, viewing the EXIF with exiftool (from Terminal) shows the lens correctly identified as the EF-M 18-55mm.


----------



## bchernicoff (Jul 22, 2013)

FunPhotons said:


> Ah, I'm viewing it in OS X Preview. I'll try looking at it using something else. Presumably the problem is in the Apple RAW library.
> 
> 
> So this is interesting, what is actually stored in the EXIF - a number indicating the lens?



Yes, the Lens ID you originally posted.


----------



## FunPhotons (Jul 22, 2013)

neuroanatomist said:


> FunPhotons said:
> 
> 
> > Ah, I'm viewing it in OS X Preview. I'll try looking at it using something else. Presumably the problem is in the Apple RAW library.
> ...



Interesting, exiftool must have its own database (so you need to keep updating it as new cameras and lenses are developed?)

I wonder what LR on OS X says? If anybody has it handy see what it says, or I can check later today.


----------



## Mt Spokane Photography (Jul 22, 2013)

Lens software uses the lens ID plus other information to guess at the lens model. Where it gets diffricult is with third party lenses that use a Canon lens code. Each piece of software does its own calculating from its database, so yes, you need to update your software if you want it to recognize a new lens.


----------

