Actually it is fully tolerated and legal to do so
first of all you will not go in direct competition with the
tangible Product as it is just an Image of such.
then considering using a model witch represents
a tangible Product with the logo is not to use for your own
Purposes selling your own brand.

In the case of Cannon it is Profitable for the Industries
will someone use this model in one of He's renders it only would result to free Propaganda of the tangible represented Product.

Industries Like this sample with Cannon spend millions to Advertise there Products
and you can be sure that if they realize that there Brand has been used for a render
without charges they would kiss your Hand.

for example you make a Advertisement using Poser Renders for your own Company
there shows in the background that Camera with the Cannon Brand .... the visual communication effect would be ... in foreground the company as main Advertisement the background will only tell you we use Cannon Products , therefor the brand will not be able to sue you as you only made an supplementary advertisement in your Product and you don't go into direct competition with Cannon

Remember the world is not all Virtual jet