What are optimal sizes for slider images and home page video?

[Shambhavi]

I have chosen Narrative theme for my website. Need help with the home page slider images and video sizes. Can some one please help me with the exact sizes to make images fit and also responsive with phones and tabs devices too. 

[RonkyBest]

The recommended size for slideshow that fit almost all theme is 1500 x 600px. Make sure to put the image positioning as center to appear well also on mobile.

Note: some parts of the image will still not be visible on mobile, so make sure your image design has core information at the center. I hope this helps?