Well, playing around with the big Tamron 150-600mm lens on vacation last week, I decided to experiment and see just how much the zoom, crop factor, and a whole lot of cropping could do in capturing Cuba as we sailed just outside territorial waters, roughly 12 miles from the coast. These are 100% crops, taken at 600mm, handheld from a boat...of CUBA!: This is off the far eastern coast - the point that sits closest to Haiti, bordering the Windward Passage. It's also shot through a ton of haze, salt mist, and humidity (the original was nearly a white out, and I had to play with levels to restore some contrast). Surprising how much detail of the lighthouse and small town are visible from 12 miles away through horrible atmospheric interference! Here's another, at the exact opposite end of Cuba - the far WESTERN tip of Cuba which is non-mountainous, and also has a lighthouse: There was a cool front dropping down out of the US, so the temps that day were a more mild low 80s, and the atmosphere was a little clearer - there's still some distortion since we're dealing with MILES of distance and over ocean with salt spray and humidity, and again a 100% crop. This won't thrill Mexicans, Canadians, and Europeans, who can all go to Cuba at will, but we Americans are still restricted for travel there, so this is about as close as many of us can get to Cuba without upsetting the authorities! Quite a spy lens, this 600mm Tamron, with a 1.5x crop!