If this was in the UK then AFAIK we don't get cardinals here, and they are much larger than the comma. I believe they're actually fritillaries. The wing shape of a comma is unmistakable, but your images don't show it off very well. Get yourself an ID book. The butterflies will only get better for several months now and it's galling when you don't know what they are. Just a hint - it's better to photograph butterflies when everything's in the same plane, ie either from the top with the wings flat, or from the side with the wings folded. Some don't make for good images with wings folded, some are almost impossible to catch any other way. With the whole insect in the same plane you can get in close and still get the maximum amount of it in focus with the right aperture, but always spot focus on the head. If they're settled and not too flighty it's fairly easy to get into a good position. Just like any animal or bird, move carefully and slowly, and don't let your shadow fall across it if it's in the sun. As with all wildlife, think about presenting it at its best - attitude, location, background, lighting.