Describe the available frame
Identify the source shape and the space it must occupy in the presentation. A portrait demonstration inside a wide canvas needs a deliberate layout decision. Filling every pixel is not automatically the same thing as preserving what the viewer needs to understand.
Compare the supported transforms
OBS’s Sources guide distinguishes fitting, stretching, resizing and cropping through its transform controls. Preserve the current transform and compare the two choices relevant to the task. Use a source containing recognizable proportions and labels near the edges.
Inspect whether a round object remains round and whether required edge labels remain visible. These are authored visual checks, not a calibration measurement. If one choice fills the frame but distorts the diagram, consider a layout with surrounding space instead of treating the distortion as a source-media fault.
Judge the final viewing size
Record a short sample and inspect it at the intended presentation size. The operator’s enlarged preview can make small text look more useful than it will be for the audience. Keep the transform that preserves the required information and document any intentional crop.
No transform or recording was tested here. The guide explains a decision between presentation controls and does not claim that scaling creates additional source resolution.
Questions answered
Does filling the canvas prove the proportions are correct?
No. Inspect recognizable shapes and the information at the edges.
Can unused space be acceptable?
Yes, if it preserves the content and supports the presentation’s purpose.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.