Calculating Hyperfocal distance with adapters
 

I have just bought a Samyang 14mm and am trying to calculate it's hyperfocal length. I'm using this online calculator and NEX-7 as the film format (EA50 not listed)

Online Depth of Field Calculator

The problem is that I'm sure the metabones adapter I use must have a bearing on the calculation as it pushes the lens a certain distance from the sensor. I'm planning to use it on my merlin instead of the 16mm pancake lens - it seems much sharper.

Any ideas?

Pete