What are the best export settings for a stop-motion video

Video formats are typically 1280x720 (HD), 1920X1080 (FHD or 'full HD) or 3140x2160 (UHD). Also 23.976/24/29.97 for frame-rates.

So for most puposes at the moment, the 1920x1080 frame-size is the preferred typical export for broadcast or web. 3140x2160 or UHD is gaining use. Use one of those for your Sequence settings. At a standard frame-rate as noted above ... pick one.

Typically, Premiere does better with modest sized stills, not more than 3x/4x the frame-size of your sequence. Your chosen stills size should work fine.

Also ... set your scaling preference to "Set to frame-size" so when you drag/drop an image to the sequence, the whole image appears but the image is not 'set' and re-computed as an image at that frame-size. "Scale-to" does ... and means if you then zoom in, you're uprezzing the sequence frame-size rather than going from the original larger image.

And there's a preference for length of still images ... you could set that for whatever you feel is going to be a normal length viewing of the images.

Then export using the same frame-size/rate of your sequence, and sharpness should not be an issue.

Neil

Dpi is totally irrelant to video: all that matters is height and width in pixels.

For web most common codec is H.264 in mp4. Loads of presets but you can always bump the bitrate.

Stills will be reduced to video resolution as will the sharpness.