You are right, I don't believe the solar charging on powerbank. It's only for emergency sitituation. I choose a solar power bank because of it's capicity, size, weight and reliable or not. I recommend the tainbat solar power bank 20000mAh. It's not a famous brand, but my brother recommend to me because he tried it 3 months ago. it's IP65 rainproof and dustproof, good for outdoor trip. It's rugged which support 1.2 meters drop. 20000 capicity is enough for 2-3 days weekend trip, which can charge my iPhone 3-4 times because I always keep my cell phone in low-battery mode, so that I can keep it longer. For your two smartphones and camera, I guess you need two of them. I bought two for myself and my hiking partner. It's also lightweight and small size, I can hook it on my backpack, so that it's charging while I walking on the road. Also the bright 2 LED flashlights help a lot while at night. Here is the link, hope it's helpful for you. https://www.amazon.com/dp/B08T71D9PP