I went over the 2006/2007 holiday season with rock climbing being one objective. At least at that time, climbing was not an authorized tourist activity, so climbers traveled under the radar. We networked with some French ex-pat climbers and shared a modest boat. I was told that regular tourist junk boats have to be of a certain size and accommodation. Our "under the radar" boat had paid the necessary "payouts" to travel to spots outside the norm without much fear of authorities. We slept on pull-out mattresses and ate some wonderful food cooked in a one-wok pot over a propane burner. I should think that size/cost for a smaller boat would be good support for individual goals like photography. The boat came from
http://www.catbaventures.com/ and there's climbing destination info at:
http://vietclimb.vn/guidebook/.
I'm guessing that Catba island is a good base for your magic hour photos. There is a road over the top and I think it yields some elevation and the possibility for multiple views. We accidentally took a bus to a larger fishing port the north of the bay, and then were actually in the wrong place for transfer to Catba. It took us extra travel money and a whole night to get over to Catba from there. Instead, there's a 20-minute public shuttle from the west side. On Catba we stayed in the top floor of a 6-story hotel.
And HaNoi is great for people, eating and drinking. The best tofu I've ever eaten came from a "homestay" farm along the south Vietnam/Cambodia border. Hope that confuses enough.