Croping Question

I use elements 6 for my processing. When I pull the picture up for editing it comes up at 16%. If I crop it for a 4 by 5 will everything be the same if I were to push it up to 33% and crop it as a 4 by 5? Will there be any differences in sharpness or even if I push it up to 50% and crop it 4 by 5?

Is there a recommended size you should work your crops from?

The % is simply a magnification used to display an image on the screen and has nothing to do with the actual data of the image itself. Display the image at a size you need to view the area you want to keep and crop. All the data in the crop box irrespective of magnification will be kept.

Thanks, I thought that might be the situation but I was not sure.

It is generally most convenient to have the image displayed at a size where you can see the entire image, but if placement of the crop lines has to be exact, zooming in may be needed. One of the complaints some people have about Lightroom is that cropping cannot be done while zoomed in.