It looks just like my bag, except the price tag I'm gonna try to make mine work before investing in Ortlieb. I like Ortlieb, but I bet there's a minimal functional difference if I use my head and do it right.

UPDATE: It looks like the Zoom bag is just too long to attach on my front handlebars via straps through the D-ring. I no longer have the Zoom lens, so I might see about getting a smaller bag. It seems like the easiest solution (strapping it on my body) might be the one I default to. I will update if I find a better solution by counting on the wisdom in the responses.