Categorizer is a very versatile tool to sort, delete, categorize, crop and export your photos. It is written with high volume in mind as event photography tends to generate large volumes of photos. All common commands are available as shortcuts from the keyboard. Other then the obvious start number or category number input is deleting by hitting minus, add multiple start numbers after hitting plus, crop image by first hitting z and then any number in the numeric keyboard matrix to make the corresponding crop. The quick crop tool is invaluable at fast moving sport events where it is hard for the photographer to frame each photo perfectly and by making it accessible as a short key combination you don't loose speed. Remember that speed is the key in event photography, time from shutter activation to presentation to customer should be as small as possible. The thumb list color codes the thumb border so you quickly can see what photos has been completed and you always skip a photo and come back later. Click 'Show only new' and Categorizer will step to the next photo that has not been categorized and skipping all completed in between. This is a great feature if you have a large number of photos of the same object and want to select only a few of the best ones to be presented. You can also analyze highlights and shadows with the built in histogram.