Adjusting image size in Ajax portfolio

In the Ajax portfolio, my images are often being shown at a size larger than the native image (which results in blurriness).

The problem is, my illustrations are often different sizes and orientations depending on the project. So some are very tall, while others are very wide. So simply trying to restrict the size of the content area won’t work, because a result that makes a tall image look good will cause a wide image to appear very, very small.

A good example is the first image in my portfolio on the link I provided in the private content section. The actual image is around 450×800 px. But Ajax is displaying it at around 600×1000. This makes it blurry, and takes up way too much space.

Is there any way to set it so the images resize to fit the content window UNLESS the size is larger than the actual uploaded image. So there would be a maximum height or width? My images are never taller than 800px, and never wider than 800px. A tall image is often 300 px wide, but around 800px tall.

The images also often (especially the tall ones) fill up more than the user’s screen when they are viewing it on laptops, and they need to scroll down. I would love to be able to set a maximum height.

Please help! I’d be happy to hire a moderator to fix this problem for me.