A couple of days ago, at work, we were discussing Oil Well Image Logs, where instruments lowered into the borehole record photo-realistic images of the borehole wall.
We were comparing these with core photos, which are photographic images of retrieved core samples.
One difference is that the Image Logs are from the inside, looking out.
The core photos are from the outside, looking in.
Ever since that discussion, I've had Pink Floyd's "Wot's... Uh the Deal?" from 'Obscured by Clouds' going around in my head.
For about 2 days now.