My game has a default resolution of 1280x720, and to achieve that on my interface map control, I used a view of "40x40".
For the gameplay itself this view works fine :
But when I take a screenshot using F2 it gives me a 1280x1280 resolution image (maybe because, 40x32 = 1280 I don't know) :

I don't know if it is possible but, I want to solve it. How can I know that the view that i'm using is the one used for a 1280x720 game ? And how to properly configure that.
Thanks, best regards TacurumiN.
With an icon size of 32×32, it's impossible to perfectly fill a 1280×720 window because view only accepts whole numbers.
1280÷32 = 40 (this is where your 40 view width comes from)
720÷32 = 22.5 (this is what your view height would need to be)
"40x22.5" would be perfect, but you can't have the .5, so you'll have to go with "40x23", which would make your screenshots 1280×736, or "40x22", which is 1280×704.
I suggest changing your window dimensions to multiples of 32 to better fit your inevitable view size.