The Dolomites in the winter is absolutely beautiful. The snow is deep, and the mountains are very photogenic. I didn't get to spend too much time photographing here like I wanted to though. That's because I came here without a car (big mistake). Getting around the Dolomites without a car is nearly impossible. There are buses, but if you're there to take photographs during sunrise and sunset – you're pretty much out of luck. Buses stop running once the sun goes down, and if you're like me traveling on a budget without winter camping gear, staying in these fancy ski towns is pretty expensive.
I opted to couch surf, and since I was here right around Christmas time the only place I found was an hour outside of the Dolomites. So I got to spend only one day taking photos of one location in Val Gardena, and that was the Seceda Ridgeline. BUT, since I had to catch the last bus and take the cable car down to the city I wasn't able to photograph that spot during the sunset liked I hoped for. It also cost me $50 to ride the cable car up and back down.
For me, it would have been a much better experience spending time in the Dolomites if I had a car. I wasn't able to explore at all. Being dependent on the trains and buses in this region was a big disappointment. I was alone traveling here – so I wasn't able to afford renting a car either. Hopefully you'll be here traveling with friends and can split the cost of renting a car.
The other downfall of being here in the winter is the lack of open refuges. In the Spring, Summer and early Autumn there are refuges that you can stay in. You can even trek refuge to refuge passing by the best photography locations. This would allow a better photography experience since you can be out in good locations during sunrise and sunsets.