They were easy to see in person as 6 of them buzzed about a lavender plant along the walk outside my studio.

But when I tried to capture them with the iPhone that happened to be in my pocket, the result was less obvious. I first thought were some new-to-me variety of hummingbirds, traveling quickly in and out and around the lavender blooms and evading my efforts to capture their image.
I cropped this guy out of the photo above, edited the contrast and shadows and it is still hard to see him ... though he buzzed about in a typical hummingbird way, he didn't look like any hummingbird I'd ever seen and so I did some research ... and found the White Lined Sphinx Hummingbird Moth. They really seemed to enjoy lunching on my lavender.
I found a much more lovely photo of this interesting moth on the blog,
Morning Bray Farm.