B&H published an interesting review of the Canon EF 1200mm f/5.6 L USM lens currently available in their used department (see also this post):
With the Canon 1200mm lens, planning involves not what to bring and leave behind, it starts with this question: “How many people do I need to bring with me to carry the gear needed to get the shot?” If you own this lens, you had better have at least one friend who is passionate about photography and willing to carry heavy loads. You may be better off with two or more friends. Carrying the lens, camera bodies, and supports is more accurately a 2.5-person job. Hauling the gear to a location and shooting a lens like this is more akin to a logistics challenge than simple planning.
Also, there is nothing casual about this lens. You cannot just decide, on a whim, to take it outside to make some photographs. If you want to try to use the optic to its fullest potential, you will need to scout locations, have ideas of what images you want to capture, and keep an eye on the weather. Remember to do all this while coordinating the schedules of several other people who you will need to pull this off.
Here is an example of the zoom capabilities of the lens:
Canon EF 1200mm f/5.6 L USM lens specifications:
| Lens Mount | Canon EF |
| Focal Length | 1200mm |
| Maximum Aperture | f/5.6 |
| Minimum Aperture | f/32 |
| Angle of View | 2.1° |
| Minimum Focusing Distance | 45.9' / 14 m |
| Autofocus Motor | USM |
| Image Stabilization | N/A |
| Weather Resistant | Not Supplied By Manufacturer |
| Magnification | 0.09 x |
| Lens Construction | 13 Elements / 10 Groups |
| Diaphragm Blades | 8 |
| Filter Ring Diameter | 48mm Drop-In |
| Dimensions | 9.0 x 32.9" / 228.0 x 836.0mm |
| Weight | 36.4 lb / 16.5 kg |
| Compatibility | Canon EF Mount |
