HI Judy,
A trick I learned from Chuck and Kimberli Downs for pictures was to put a little oil of cloves in the water to "calm" the fish. When I am having trouble getting a good picture, I pull that out. Not enough to knock them out, but it does work quite well. For me, a rectangular tub works better than other shapes, ideally much bigger than the koi and blue. I bought a 5 foot long one at Walmart ( I think) years ago. It seems to work better because the koi can swim straight down the middle. (Though they do not always do that without "encouragement"

)
These are decent koi with a good bloodline. Looking at the pix again, the weakness in the hi is evident, especially in the second picture. 3 years old is early to have that weakness. I have seen many parent koi in Japan that are not the greatest looking, but throw off good babies. But they are much older. If you want to breed them, you should go ahead. At the very least, it will help learning..
Hope that helps.