Manually Resize Image

[thecanman]

Is there a way to manully resize a source? If I try to shrink one side, the entire source shrinks. I just want certain part to shrink

 

[Suslik V]

If you want to cut OBS source from one side only then try to hold Alt key and drag bounding box of the source by mouse (red bounding box turns green).
Same action is possible by right-click menu Transform > Edit Transform over the source (there look at Crop fields - top/bottom... etc).