Camera Projection - Nuke 101: Professional Compositing and Visual Effects - page 483

In input fields, you can use the words “width” and “height” to ask Nuke for the
current resolution as a number. This is very useful for a lot of things. If you need
to know the middle of something, for example, you can just enter width/2 for the
horizontal middle point.
23. At the far right of Grid2's Properties panel, click the 2 next to the Number field
to enable both fields ( FIGURE 11.36 ).
Figure 11.36. Enabling the X and Y Number fields.
24. In the Number.x field enter width/16 .
25. In the Number.y field enter height/16 .
You now have perfect squares that are 16 pixels wide and 16 pixels tall.
26. Change the Size property from 1 to 6.
You now have an LED screen ( FIGURE 11.37 ).
Figure 11.37. The grid is ready.