Welcome to TVPaint Community forums !

<t>I've been using TVPaint for a while and have just spotted this option, and also the option following it - "display with video". I have searched TVPaint and Google and have not been able to find what either means.<br/>
I'd like to understand and also to know what should be ticked or unticked for these.<br/>
I guess a related question is: where exactly are all those View options explained? <br/>
Many thanks for answers.<br/>
John</t>

Do you remember CRT TVs ?
On those, pixels weren't square, and "Display with Aspect Ratio" simulates this.
I guess today you can safely ignore it (leave it unticked), unless you make your animation specifically for these old devices/video formats (PAL & NTSC)
To see it's effect, you can create an NTSC or PAL project and toggle it on and off.

Display with Video, for what I remember (!), enables you to display the video from a video acquisition board in the background of your project window, but I may be wrong...
That was used for stuff like rotoscoping, etc...
Nowadays your reference footage is all digital and you just import it into a layer.

Many thanks for your reply - you have been really helpful.
All the best
John