I'm i the same place right now needing a way to change film in 8x10 holders on the road. The Harrison as David suggested does seem to be the best out there, but I can't get myself to spend near $300 for it. I've found this other source who seems to make Harrison "type" pop-up tents. Garanteed to be less well made but at one third the cost.... You may find it meets your needs. Their fleabay ID is 3s-krpc. I've decided to give it a try.