Slider behaviour documentation anywhere?

Is there anywhere that documents the behaviour of the different sliders in Media Elements, specifically in how the images expand to fill a space?

I’m building a new site and the client has a bunch of images of different sizes and aspect ratios that they want to show in a slider on a post, but I cannot get any of the sliders to display the images at their original size, they all automatically expand to fill the Container width.

The site’s Maximum Container Width is 1200px and there is no sidebar. I have an Easy Slider in a 1/1 container and select No Scaling for Slideshow Image Size, which “Choose(s) the size of the image that loads into the slideshow” as the Original Width x Original Height.

To me that means if one image is (say) 650px x 400 px then when the slider shows that image it should display it as 650px x 400px.

But it doesn’t, the slider expands every image, whatever its width (400px, 600px, 550px…) to fill the 1200px container width. Chrome Developer Tools tells me the image being loaded is 650px x 400px in size but the slider is expanding it to the full container width. Why?

When I specify “display as Original Width x Original Height” why is the slider not doing that? Why is the slider enlarging / expanding every image? If I specify, say, a square image of 180px x 180px in the slider it still expands the images on screen to 1200px wide. Why does it expand a 180px wide image to 1200px, when I tell it to show a 180px wide image.

Or more to the point, how do I setup a slider – any slider – to show the images in a slideshow at their original widths, or a width I specify, without being enlarged or expanded?