We wanted to share a little about the Altus Atmospheric Poncho and why we selected these for our Camino. These ponchos are made in Spain and perfectly fit for use with an internal pack. The design is like a rain cagoule but with the added benefit of having space built into the back to allow the coverage of an internal frame pack.
They come in two sizes and the large weighs 13 oz. Though the material is coated nylon and not a breathable fabric, there is sufficient venting to minimize moisture build up.
You can compare this to a full rain suit typically used for backpacking. My Marmot Precip rain coat and pants, plus a pack cover weigh in at 28 oz. and still allow the pack to get wet in the back and strap area. The Altus provides full coverage of the pack and reduces the risks in high winds that are the problems usually found with traditional ponchos. As you can see from the picture though, the jacket is not as viable as a wind jacket to use when not carrying a pack.
We will carry a light wind jacket (InSport running jacket or OR Ether Jacket) that weigh about 6 oz. and provide another light layer as well as wind and mild rain protection. this will give a good combination for the varying conditions and allow for several alternatives in layering in Galicia where the rain and variable temperatures will be most severe.
I love the Altus poncho and am very surprised that they are not more popular in the US as an alternative for the experienced backpacker.
Hopefully we can share our experiences with it as we travel further.
Chris and Matt, I hope this helps you understand our decision.