Hi,
PureRef is a great free software for 2D and 3D designers, or people that needs a quick looks at reference images.
You can drop as many pictures as you want, can you can save your preset as a lightweight file , or save as a complete preset containing your images files.
You can have lot of images of any size it is always very smooth.
There is zoom , pan scroll, double click image to center zoom on it, full screen toggle.
It's one of my main tools and so usefull.
https://www.pureref.com/
