Some softwares allow preview of video corrections with a DUAL effect or SPLIT SCREEN: with and without correction. With Studio it is not expected and we must "cheat" !

Dont' worry this trick is not very long to implement, but its result is good enough to make adjustments in good conditions.

All you need is to duplicate the correct sequence on the overlay track and to apply an effect of PIP as you see below with the settings "Position" horizontal et vertical set to zero - or Presets on "Full screen". (Do not forget, and possibly before, to right-click the image and click in the dropdown menu on "Zoom picture to fill frame" in order to avoid vertical bars.)

The viewer is then divided into two parts left and right. But since no effect has been applied, the line does not quite see.

Now you can use your video correction effect. For this tutorial, I chose an effect WLFilter Poster (2.0)

The left side of the viewer displays the original image and the right side of the viewer reflects gradually settings changes as you step on the setting of Poster (2.0).

Alas, this trick does not work with many effects that apply to the total area of the screen or with some third party plugins such as Magic Bullet Looks, Heroglyph, Vitascene that interface settings masks the entire screen of Studio. You still have many other effects for which this trick applies to send us your comments.

{Thanks to saby who translated this tutorial from french to english and cross-checked it}