(See the best response by Kaiochao.)
Good afternoon guys,

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.
Best response
If you have a view of 40×40, with an icon_size of 32×32, then you'll definitely have a total view of 1280×1280. Your window simply cuts off the extra view size.

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.
Thanks for the help and for the tips !

I will do some tests.

Tested with "40x23" view, and here is the results :

Changed all the interface dimensions to 1280x736 and now on the map i have a big black rectangle :

And on the F2 screenshot now i have a 1280x1024 image :

Ignore the above post. Problem solved, thanks Kaiochao :D
I'm guessing your HUD is positioned badly.
Yes, the problem is the Hud =D