I don't understand this smugmug focal length equivalence

[rpcrowe]

I shot this image using my 7D Mark II which obviously is a crop format camera which provides a 1.6x crop factor.



I shot this with my new/old Tokina 28-70mm f/2.8 ATX lens. Obviously, Adobe Camera RAW doesn't recognize the lens and thinks that it is a Canon 28-70mm, f/3.5-4.5. Unfortunately it seems that Adobe no longer provides a user with the capability of making a custom profile for a lens which Adobe doesn't list on ACR. I wish it did! However, that is not what I am writing about.

Smugmug.com consistently provides erroneous equivalency for images shot on a crop frame camera. Since the 7D2 has a crop factor of 1.6 and I shot this image with the lens at 42mm; obviously (or I think obviously) the 35mm equivalent would be 67.2mm, not 266.8mm (circled in red). Am I reading this wrong? With the smugmug.com information, the crop factor would have to be about 6.35x.

This happens with all my crop cameras and all my lenses, not just the Tokina on the 7D2. No big problem but, why should they have this at all if the information is so incorrect?

[DanK]

I just looked back at a handful of photos that I took with crop sensor Canon cameras, and Smugmug had the equivalency correct for most of them.

[xpatUSA]

Had a look in your smugmug but couldn't find the lady above, so down-loaded and looked at ALESHA_2739. I used ExifGUI and also JPEGsnoop.

No EXIF tag was found for equivalent focal length; not saying there should be ... viewers are a law unto themselves. For example, smugmug thinks that the CoC for that shot is 0.003mm (look in advanced information), field of view 2.6 deg, hyperfocal distance 326.67m - none of which are believable.

In the EXIF 2.2 spec, there is an available tag #A405hex:

FocalLengthIn35mmFilm
This tag indicates the equivalent focal length assuming a 35mm film camera, in mm. A value of 0 means the focal length is unknown. Note that this tag differs from the FocalLength tag.

Tag Type Count Default

= 41989 (A405.H) = SHORT = 1 = none

There is no rule that says this tag should be in the meta-data for any image. If apps were to put all possible meta-data into an image, the file would be pretty big!

I conclude that smugmug can not be trusted to present EXIF correctly, although it seems to get some tags right.