Enlargement software

I have images from both a 4, 8 & 12MP camera that I'd like to enlarge. I often shoot underwater and would like to be able to zoom in on part of the frame & enlarge only that part.

What software out there does a great job? I've heard good things about Fractals.

Scott Kelby recommends a "Rule-breaking" method for resizing for poster-sized prints by typing in the final print size in the "Image size" toolbar then choosing 360 in the resolution field & choosing bicubic sharper. He states that they guy who taught him this technique (Vincent Versace) gets better results up to 24x36 than the expensive plug ins. I need to go even larger, perhaps up to 60x80.

Can any software do this yet maintain a good final quality?

I routinely bump the export size by one size when exporting from ACR. When you have one of the RAW files open, the export size picker will list all of Canon's available sizes. Bump it up one and export and you would be hard put to see any image quality drop from the larger image. This works good for one size jumps, but you can start to see degradation at two. I think starting by exporting one size difference from ACR, then do other ways later might work better. Just a thought.

The advice you've read is years old, forget about it. Just do a single step upsize in Photoshop with the bicububic smoother algorithm (recommended for enlargement), it will be as good as anything out there. Doing it in RAW is an interesting idea, no idea if it make any difference - try it and see.

For images where I am going well beyond what I would normally do in Photoshop I use Genuine Fractals. It does a bang up job of it too.