I've got a bunch of paintings that I need to crop in Lightroom, but I want them to be pixel perfect crops. As far as I can tell, there is no way to zoom in while cropping. Without being able to zoom in, it's almost impossible to crop to the correct pixel. I saw someone mention using a second monitor to get a better idea of what they were cropping, but I'm not sure what they're referring to.
Does anyone have a good workflow that they recommend for this sort of problem? The goal is to have all of the paintings level and cropped to their exact edges. Do I just need to use Photoshop? If so, what's the best workflow to export, crop, then re-import to Lightroom?