I put my dslr with a lens attached (either the 18-55mm zoom or the 55-300mm) along with whatever lens is not attached, a macro and fisheye, charger filters and spare ad card. That pretty much maxes out the space. I have a hard time imagining fitting the flash too. Maybe the flash could be strung on the shoulder strap if yours has a case with belt loop. Strap on this case is removable.