Beautiful processing and I like how you captured the light of the day in the sheen on the boys' backs, and how the dark and light patterning of the background tree line makes it's own rhythmic contribution to the composition. I admit I did not see the rhythm in this until I was able to read your explanation - but I appreciate the thought and subtlety here. I find myself wanting to see less of the foreground grass...but I can't tell if removing it will help or harm the image overall.
Don, sometimes I feel like you're playing with us. You know exactly what you're doing, and it's like you dare viewers to figure it out. I'll be the first to admit I didn't get it, and I still don't, but just knowing it's yours makes me look more and try to find it. As an image outside the challenge, I agree with Larus that the tones and composition are quite interesting.
Well well, I get assigned to one of your photos again, hehe :)
Again, I don´t really get how it ties in with the challenge, to me rythm was more about repetition of something, had maybe a couple of the boys been in the same position jumping into the lake or something, that definately would have met the challenge as I interpreted it but frankly, had I voted I would have given you the benefit of the doubt, however that doubt still would have prevented me from giving a very high score. Think I would have voted this a 6 because I really REALLY like the b/w processing work I am seeing from you lately, these tones really appeal to me and look very film like, wich is a huge compliment. Frankly am amazed you can pull off images with this b/w look with a p/s camera so coudos from you.
Composition is also very good, personally if I had processed this shot, I would have cropped it to a more square format, taking off the shadow at the bottom and a little bit off the trees at the top but I can understand why you decided to keep the crop as it is, it just would have appealed more to me personally if it was more square cropped.
Not really much more I can say except nice work, I dig it. Kind regards from Iceland, Lárus.