I use a gas mask bag sometimes when I am in a hurry, and recently I was a census worker, so I used the stock census shoulder bag.
This is what I have to say: canvas bags are no good for the simple reason that there is not much protection from banging into the odd doorway.
As for canvas bags in the subway .. sure if blending in is your appeal, but what happens when your bag gets stuck in closing subway doors, or you get pushed into a subway pole. Leica lenses on the outside ?? I cringe when my Jupiters hit something hard. I banged my Jupiter-8 many times during the cenus job, but fortunately the filter took all of the damage.
I can see why pre-war photogs liked folders and telescoping lenses -- keep it in a pocket close to the skin and covered with a coat. But then with the TLR everything must have changed.
As it happens, I can slip my Bessa R into my sheepskin demin jacket outer pocket in winter, and my unlined demin inner pocket in summer. The length of the Jupiter lens keeps the camera from falling out. My Jupiter 135mm goes in the left breast pocket, and the viewfinder goes in the right. When I get a 35mm, probably a Jupiter-12, things will have to change, as those don't screw onto the Cosina rangefinders, meaning there will be a light meter added.
SLR lenses are too heavy for jacket-only photography, but my OM-1 fits pretty well detectives keep their .38s, in the left arm-pit, but the lens strap has to be long enough to pull the camera up to the eye, and pretty strong too. I used a snake chain strap for a while, and its flexibility and slipperiness worked for me, but I felt I was going to break it at some point and tried other straps. Best so far comes from a SONY boom box; that I fit with two tough-looking shap hooks from an orpahned luggage strap.
Under the arm-pit the camera is pretty well protected, but lens caps seem to get brushed off pretty easily especially when walking through the brush. This is probably why I used filters most of the time now, taking the time to unscrew them for better shots.
My cameras live plastic soda trays that look like short milk creates. I can put them in the back of my hatchback car (with the back seat folded down) when I want to bring quite a few, and I cover them with coat when I park. That doesn't help in the city where driving is infuriating and parking is impossible, but for the country it's the way to go. Drive close to where you want to be with all your gear, and then hike the rest of the way with what you think is appropriate. And if its hiking that you are doing, there is no other bag than the knapsack. But that brings back the banging around-problem. To deal with that, I have been using fleece ski caps as individual protectors and then I wrap the whole kit in a fleece jacket.
All in all, I think the demin jackets work best for me, along with the .38 special strategy--as long as I stick w/ RF and TTL metering.
