Not sure where this should go, so please move if needed.
I post a lot of my stuff to Tumblr. I also have a Flickr that I recently opened. I notice that when editing in Lightroom, and when posted to Flickr, the focal length exif is correct. But when I post to Tumblr, its often incorrect. For instance, if I use my S35mm, LR/Flickr says 35mm. Same photo posted to Tumblr says 37mm. Long end of my 24-105 will say 112mm. 135mm F2 says 145mm on Tumblr. This is not really a concern, more of a curiosity. I was under the impression that exif is embedded info, so shouldn't it be the same across the board?
Using a FF camera (6D)
