Specialty Camera bags are expensive, trust me I have two (Backpack and Should Bag) both over $150. The worst part, they don’t meet my needs. I found alternatives.
Shoulder Bag:
I use a LA Police Gear Bail Out Bag, around $30 when on sale and they are on sale a lot. They have multiple pockets, interior and exterior are very roomy. I can carry a water bottle on the side, some bags carry two. I can carry multitude of gear I need: microspikes for slick surfaces, mutli-tools for in field repairs, white balancing cards, head light and small flashlight, rain cover, business cards, and my typical photo gear; lenses, filters, cable release, cleaning kit and what else but the SLR Camera. Plus rooms for all the other items I like to carry just in case, plastics bags and paper towels. I usually just carry my tripod or strap it on the side of the bag.
The bags are not water proof, so little protection in a strong rain. I always have protection from the rain for my camera; I just need to keep the rest of my equipment dry. My equipment is kept dry with some hiking dry sacks that you can get for the cheap at places like Wal-Mart $10. So when the rain comes, the equipment goes into those. Plus I always carry around some zip lock bags to keep the water from any other equipment that might not be in a dry sack.
Backpack:
Along with photography, I like to hike and whenever I hike I have a camera. I especially like day hikes in the Monongahela National Forest. I have never found a ‘Photography Packpack’ that has met my needs. The major problem, they are made for carrying photography equipment and that is about it. Yes I know some on the market have more features but are expensive. When I hike and take photos I take a multitude of items along: jackets; maybe a wind breaker, fleece, and or a rain jacket, extra shirt, change of socks, sometimes extra shoes for water crossings, first aid kit, hiking maps, muti-tools, knife, fire making kit just in case, and small survival kit just for an emergency. I might also have a few extras like another pair of pant’s depends on the weather, along with a hat and hiking poles. Also in that pack is all the gear I mentioned above that is in my shoulder bag. The best part of all that extra clothing is padding for my camera and lenses. Last but most importantly, water, usually a camel pack and sometimes two water bottles on the outside. A Photography Pack just can’t hold all that.
What best fits my needs? It is a Hiking Backpack with a built-in rain cover. Since I do mostly day hikes I don’t have a very expensive pack, I got it at Dunham's, been a while but I think it was around $80. The cover keeps all my equipment dry when the rains comes and believe me I have been caught in some downpours with it. I transfer my equipment from my shoulder pack that is already in dry sacks so it adds extra water protection.
With the Photography Packs I am not a big fan of the vertical tripods holder, they tend to have a torque effect and pull back on the pack. So I found the best place for my tripod is at the sleeping pad location, usually on the bottom of the pack and stores my tripod horizontal which for me it is much more comfortable that the vertical.
To meet my photography bags needs I had to think other than a “Photography Bag’ which meets my needs, has worked out well, and does not cost nearly the amount for a Photography Bag.