That sounds like the beginnings of a great plan, DD.
I hope we're not losing you in the translation, because as we give you more details, it's going to get more complicated.
I'll first tell you that Vogelsang is very beautiful and photogenic. I don't store my own photos online, but I think Balzaccom would probably be happy to fill in the gaps where I can't.
Without getting too specific, you have two main areas of attraction for most visitors: Yosemite Valley and Tuolumne Meadows (Tioga Road). Buses and shuttles serve within both areas well, and between the two enough to get from one to the other and back fairly often and well. Being without a car, this is something you should familiarize yourself with early in your planning.
Besides taking photos in the Valley, you should try to spend some time above it on the north and south rims, before going up to Tuolumne Meadows and the sights/trails there. I would think maybe plan at least 5-6 days for it.
In Tuolumne, there is Cathedral Lakes, Rafferty Creek/Vogelsang, and Glen Aulin/Grand Canyon of the Tuolumne, but there's also Lyell Canyon. Further back on Tioga Road is Ten Lakes. To the east of Tuolumne is Gaylor Lakes.
You have a lot of research and planning to do, but one suggestion would be to either use the High Sierra Loop as the basis for your backpacking route, or to maybe even see if you can win a spot in the lottery for staying in the High Sierra Camps themselves if photography is what you want to do and backpacking is just a way to do it.
Try this link for some ideas:
http://www.travelyosemite.com/lodging/h ... rra-camps/Above all, get that map.