I was just wondering if I am doing this correctly. I go to admin-tools-image handler to use image handler to upload my product images. However if I upload my small image (126x155) it will dixplay 3 sizes...

126x155-small
280x345-medium
400x493-large

which ARE thie sizes I want, BUT obviously the largest size it will actually be when viewed in my store is MEDIUM.

When I upload the largest file (400x493) it displays all sizes as 400x493, BUT when I actually browse through my store the images are all resized to the sizes I have set in admin-config-images BUT the file sizes are all ~30-40kb (which is the large file size)

It doesn't seem as if it's working right but then again I'm new to this.