It maybe a dumb question but I'm wondering if the brand of a lens always matters? I have a Rebel T6i. Which I figured might be a good entry DSLR especially for the cost of the bundle I got for it. What I really want to do is night sky shots landscapes and also maybe some portraits/pets in the future.
Right Now I have a an EF-S 18-55mm and an EF-S 55-250mm Lens for it. But looking for those with greater zoom capabilites I want to know if i'm restricted to pretty much only canon now or if other lenses are compatible with the body than canon. I'm sure they'd say in specifications but I figured I'd ask before I wasted time looking and considering other brands.