Samyang 14mm and EXIF

Just got one of these fully manual lenses, and downloaded the first images into LightRoom. I notice LR doesn't recognise the lens when filtering based on lens focal length, which makes sense since there's no communication between the lens and camera. However the focal length EXIF metadata states 50mm, which is clearly wrong.

That's all fine, I can filter to get all images taken with this lens, and using that apply a lens correction profile to take out the distortion etc. But I'd like to correct the EXIF data. Can't seem to do that in LR.

Any tips/ideas? I'm on Mac, so Mac-based software solution is preferable.

I've wondered this same thing as I have the same problem.

your best solution is to get the focusing chip for 20 bucks or so off of ebay. it allows programing for focal length, though aperture will always say the same preprogramed value. You other option is to google exif editor, but its a pain in the rear end to go through.

Mac OSX, Windows, linux option:
http://www.sno.phy.que​ensu.ca/~phil/exiftool​/
can fix metadata errors- date/time stamp, lenses, etc.