A lens with a long reach can be a really useful tool when you can't get near your subject or you're looking to compress the view. Vieing for the first close up shot of a newly elected Pope from St. Peter's Square would be an ideal occasion to use such a lens but what would be a suitable focal length for such a job? 200mm, 300mm, 600mm? Maybe with an extender or teleconverter to really get close?

One photographer, Dylan Martinez of Reuters, doing this exact job last week considered the same issue and brought along a Zoom-Nikkor 1200-1700mm f/5.6-8P IF-ED!

At 16Kg and a maximum diameter × maximum length of 237 mm × 888 mm with a closest focusing distance of 10m, this beast looked more like a military weapon than a camera lens when it was set up in St. Peter's Square on 13/3/13. Italian newspaper, La Stampa, ran a few photos of the photographer at work here and you can see his results on the Reuters blog.

The lens was initially designed and was first used in 1990, to shoot baseball at the Koshien Stadium, Japan. The Nikon website has all the details here.