#6- I like the blue circle a lot, but the inside image is confusing. Not quite a Rhino. We also have used "RCG" in the past to brand our image. Maybe play with that?
#16- I really like the RCG with Rhino Camera Gear below it. Definitely stick with that. I also like #19's rhino design a lot better. Looks a lot tougher. So maybe try doing the iris with a tougher rhino inside of it.