I have posted this request hidden as a comment about a week ago, but will now post it as feature request, as I feel this is an essential feature of a photo gallery/slideshow.
In slideshows FileRun will load the full resolution image, even if this is a studio quality image. This is the expected behaviour, but will put great strain on the user's internet connection - not to forget bandwidth limited mobile connections and server bandwidth. One solution would be to store resized images in the archive, which I consider unfavourable, as the archive should contain the original data (and it should be available for download).
With the thumbnail, a 400×400px version of the image is generated that is loaded as preview while the full resolution image is transferred. With the resolution of most mobile devices this is not satisfactory any longer and usage of only these images in the slideshow can not be enforced (to the best of my knowledge). In the ideal case it would be possible to have multiple resolutions, loading the resolution appropriate for the viewer (also 4k ready). With HTML5 responsive images it should be possible to implement such behaviour.
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