Photocells question

[autosignguy]

How many streetlights still have visible photocells these days?
This new install of a WRTL Arc in Hounslow
has one, but how many older ones do?

In my area, it's still fairly common, especially on the CU Highfield Liverpool columns... but as for new ones, not as common.

Is the Nema Socket still the photocell of choice?

Saying that, I'm surprised this topic isn't mentioned here much...