Good Morning Watchers and Friends!

It's time again to invest a little money at the time.
Unfortunately I can not decide to purchase an external monitor for the laptop or a lens.

As the new Sigma lens would be 17-70 2.8 / 4 in question. As a standard lens and for the infrared, if it is suitable.
maybe someone already has this lens ????????????????

With a new screen, I have not yet employed.
So my question to you: Have you the combination laptop / external monitor and if so, which screen do you have ???????????

have a nice Sunday!