[Grammar] "This is the first time" usage

[rlenin]

Which form of the verb is to be used after "This is the first time"?
For example, I am at a jewellery shop with my friend and I tell him pointing at a diamond ring: "This is the first time I see a blue diamond."

 

[emsr2d2]

There are other threads on this topic which you can read about using the links lower down the screen.

In brief:

In BrE "This is the first time I have eaten this".
In AmE "This is the first time I have eaten this" or "This is the first time I ate this".

 

[MikeNewYork]

I would say "have seen" or "saw".