I have various lighting around my property that I want on whenever it's dark, this is currently controlled by a timer.

There are times when it gets dark early or when it's dark from clouds etc. that I would like the lights on. There are also times when it stays light later and the lights are unnecessarily on.

I believe a photocell would work better for my lighting than the timer. Does anyone disagree?

The timer is in the basement on the wall, my plan was to replace the timer with a box and run a line thru the back and thru the block wall, then into an outdoor box mounted on the outside of the house. There are no bushes or any obstructions nor is it an area that is used so it won't be blocked or damaged. This side of the house does not get direct sunlight, but there is a lot of ambient light.

Is that ok, or should I pipe it up high?

Is there anything I should know before buying a photocell? Are they variable? Do they need to face a certain direction? Should they be in the sun or the shade, etc?