It comes in handy to have a good pair of pants for photography. I find pants with extra pockets are a lifesaver since you always need to carry extra stuff such as filters or a shutter release cable. Also, the ability to carry extra stuff, in general, is a bonus.
I recommend buying the 5.11 Tactical Stryke pants. The pants are built well and are 65 percent polyester and 35 percent cotton. This blend makes the pants tough, and they will dry quicker than a traditional pair of denim jeans.
The pants have cargo pockets and additional upper front horizontal pockets on both legs. These pockets are ideal if you carry items that have clips. I carry my knife and flashlight in this pocket. Being able to do this takes things out of my front side pockets. I carry filters and a shutter release cable in the cargo pockets. Additionally, I carry snacks in the cargo pockets.
These pants are typically 75 dollars, so they are expensive, but they at built tough. The fit is also not baggy, which is a plus. A lot of tactical pants are on the baggy side. You can wear these pants out on the town and not look out of place.
Another pair of cheaper pants are the LA Police Gear Men’s Water Resistant Operator Tactical Pant. These pants pretty much have the same pocket layout as the 5.11 pants and have the same poly-cotton blend. The price is good at 40 dollars. The main disadvantage is that they are baggy and do not have a good look. I only recommend wearing them when you need the functionality of the pants.
Overall, I hope this helps out. A good pair of pants can make photography more fun and productive.