Is it okay for photographers to shoot with both Nikon and cannon? Or should you stick to one brand?

Is it okay for photographers to shoot with both Nikon and cannon? Or should you stick to one brand? - 1

It is ok to have 2 brand

It's a matter of PERSONAL preference and comfort. There's no rule, regulation, requirement or law that limits what you use. IF you feel comfortable, go for it!

I shoot with Pentax, and I was probably doing so before you were born.

Anyone shooting with a cannon in a public place will shortly find themselves the focus of some VERY intense police interest - if you were allowed within 50 feet of a camera, you'd know the camera manufacturer is CANON.

It could become expensive if your talking DSLR

Suit yourself, that is the only thing to do. My DSLR is Nikon, but my upmarket compact is Canon.

Like owning a Ford and a Chevy or having a Windows based computer and a Macintosh… There's no "OK" or not - it is what you want to do. In this case, the "camera police" won't come after you.

It would make better sense to use the same brand with SLR and dSLR cameras so you can have interchangeable lenses rather than have to buy two of everything, though you can get adapters to go from one to another, you often can't go the other way due to the focal length difference between brands.