Usually, the younger they are the closer you can get, but pretty quickly they start keeping their distance. When we're out walking in the fields one will sometimes wander up close in a "Are you my mother?" kind of way (or perhaps it's "Are you a big stick?" as they love sticks) before darting off last minute. They're also easier to approach when they've just had a nap.
The previous batch was taken with an awesome lens (Nikkor 180mm) and nice light.
We usually hike up to the lambing shed when they start popping out. Some of it's pretty gruesome, like when they skin a dead lamb and wrap its coat around an orphan to get the mother of the dead one to accept it. It's also hard to watch when the weather is terrible, as it's been until just lately, and they're shivering out in the cold.
The night shift. To the left you can see the light of a warming lamp for newborns
The shepherd and one of his helpers do their best to mend a leg
A ewe needs a little help
If her ears were a little bigger she could fly
Testing that theory
Places to go, lambs to meet