I have a Euroschirm Umbrella and used it on my last Camino. Yes, it is heavy, but it does provide excellent protection. In using my umbrella, I learned there are THREE ways to mount the umbrella:
- Use the clips and bands that came with the umbrella, fasten the umbrella to your rucksack harness as intended. This works, but takes time to do correctly. Also, if you are walking the Frances or any east to west Camino route, the sun, wind, and rain will likely come from over your LEFT shoulder. So you want to mount the umbrella on your LEFT shoulder strap to provide the best coverage
- I walked with a Belgian fellow who got a chuckle watching me fussing with my über-technical umbrella. As the rain started, he reached back, drew a standard-sized folding umbrella (@ 18" long), opened it, and stuck the handle under his chest 'sternum' strap where it intersects the shoulder harness. Easy peasy... His worked as well as mine but was MUCH easier to bring into action, just sayin...
- The longer handle on the Euroschrim is intended to allow you to attach the wrist lanyard to your rucksack waist belt. With my chunky torso (see avatar), this caused the umbrella to 'bounce" when properly mounted. HOWEVER, I found that if I removed my rucksack, I could extend the umbrella shaft fully and insert it to the LEFT mesh side pocket, UNDER the two side compression straps. This held the umbrella snugly upright and clear of my head, while working just fine. To me, this was the 'best' mounting option. It helps if your pack is full and semi-rigid.
Bottom line, if you DO NOT yet have a Euroschirm trekking umbrella, I advise taking any umbrella you have that is straight handled and maybe 18 inches / 50 cm long when closed. The key is the shaft length above the open canopy. The canopy and supporting 'arms' must clear your head.
Put your loaded rucksack on, stuff it with pillows to obtain the desired shape and consistency. Experiment with the methods discussed above to determine if one of them works for you with a less expensive, perhaps lighter weight umbrella.
When I was at Santiago several weeks ago, I bought a stout folding umbrella for a friend who was about to walk a short Camino, the Ingles if I recall correctly. Knowing the above, I obtained a light / powder blue umbrella with a long-enough shaft to use the sternum stuff method. Although only used a couple of times, it worked fine. This, I think proved my point.
The other advantage to sourcing a "hiking" umbrella locally is that you can use it conventionally afterwards more easily than the well-engineered, but heavy Euroschirm trekking umbrella. I recommend buying a light color, reflective silver is ideal. But absent the silver, white, powder blue, pale green, light yellow, etc are all good colors.
Lighter colors are better at reflecting sunlight. All colors protect equally against rain. But the lighter, brighter colors are more visible in low light or bad visibility conditions. especially if you have to road-walk.
Hope this helps.