How can I resolve height issue in slideshow for different sizes?

I have one short code that runs my grandparent album which is this:
<div align="center">[wppa type="album" album="19" ][/wppa]</div>

My final problem with this layout is that some of my older photos were taken with an early digital camera so their original size is smaller than my current camera. I can’t set the size in the shortcode because I’m dealing with 2 sizes.

So for example, this page displays correctly when I’ve set width=940 and height=600:

https://thelocalscoop.org/scooppress/pix/?wppa-album=23&wppa-slide&wppa-occur=1

but on this page there is far too much space under the photos – you don’t even see the bottom content bars:

https://thelocalscoop.org/scooppress/pix/wppaspec/ab28/sd/oc1

Is there a way to set the height as auto?

Thanks
Charles