We're expecting a baby soon, and I thought it would be fun to rent a nice lens to take some early portraits. I assume a fast prime L lens makes sense, but what focal length? Any specific lens rental companies to recommend? Thanks.
I absolutely agree with the 50/1.4 on full frame suggestions, meaning the you would need something a little wider to accomplish the same. A zoom like the 17-40 would be functional from a framing standpoint, but less pleasing due to the increased DOF.
The ability to sit right up close with your baby and still frame him/her is invaluable. When I had to drop my 5D2 at the canon service center and used a crop camera, I was constantly dismayed by the need to either back up and have him be less responsive to daddy-right-here-making-me-laugh or sacrifice framing.
My son walks now, so I shoot a mixture of 50mm (when I'm willing to chase him around for close framing) and 24-70mm (when I'd rather show him in the environment).
Word of advise: enjoy the time you have when you can place him in nice light and he actually stays there
Have fun and good luck.