Is there any way to compare distance beetwen position pixols on canvas + layer and light position? How to correct locate light using numerical values in Light>Placement tab? Why canvas have ±8000 units depth and light have ZDepth ±4 ? How use Transform>Info?
Sorry for my english 
Transform>Info is very simple. If the gyro is not active, the three sliders show the X, Y and Z coordinates of whatever pixol is currently under the cursor. If the gyro is active, then the sliders change to reflect information concerning the object that the gyro is active on. In Move mode, they would show the coordinates for the object’s center. In Scale mode they show the dimensions of the object. In Rotate mode they show the orientation of the object.
Regarding placing lights, the easiest is to click and hold on the Light>Placement>P and drag it onto the canvas. The cursor becomes a picker, and wherever you release the mouse will be the set position for the light. Its depth will be equal to the depth of the pixol on which you released the mouse, after which it’s easy to adjust the light’s Z value by a small negative amount. You don’t want to go too far because the placeable lights have a fairly small radius of effect.
Thanx for answer, it helped me a lot, especially about the Info. 