The most important factor is fit for the gear you’ll actually carry. Camera bags with similar stated capacity can hold very different kits because shape matters as much as volume. If possible, take your camera body, your largest lens, and any accessories you expect to carry to a store and physically test the bag.

For holster-style bags especially, check three dimensions: body width/height and the length of the camera with your most-used lens attached. If you use a lens hood, make sure to account for that too.

After fit, prioritize how you’ll use it: comfort while carrying, how quickly you need access to the camera, padding/protection, and space for extras like batteries, flash, straps, and cleaning items.

Weather protection is highly worthwhile for most photographers. A bag with built-in rain protection is more practical than needing a separate solution whenever conditions change.

Brand and price matter less than whether the bag suits your gear and shooting style. Better-made bags may justify a higher price if they fit well, protect your equipment, and are comfortable enough that you’ll actually use them. Testing in person is ideal because published sizes rarely tell the whole story.