So if anyone has any advice for catching them, that will be great.
First you need to start looking where they are
Why are you anting to catch Coppers? Do you keep hots? If you just want to photograph them, ther is genreally no need to catch them. My advice would be to avoid direct interaction. If you ARE going to capture them for some reason, make sure you have the proper equipment and know how to use it. But I highly recommend that venomous species not be harrassed, captured or intentionally interacted with without the necessary experience to accomplish this with a relative amount of safety.
Just my 3 cents.