How high should outdoor lights be on a ring?

[dq for life]

We are just getting the concrete poured for metal poles to be plated in. I have 6 "streetlight" style lights to be mounted over my 20 x 60 ring.
How tall should the poles be? What would the normal height of an indoor be, that the lights would be hung at?
Thanks for reading, and any help will be appreciated!

[Tom King]

30'

[Frank B]

It depends on the design of the fixture. Get the manufacturer and model number off the nameplate and then check their website. They'll most likely show illumination profiles and recommended heights. If you can't find it online, check with your local electrical supply house. If they carry that brand, they should have the information you're looking for.

[dq for life]

I worry about 30 feet for how to change a light bulb in the future. If that is where they are supposed to be, I guess we just do it, but I was really hoping to hear less.
I will try to find the info off of the lights and call too. I know they are 250 watt bulbs, so then I guess it is figured out to get us the lumen range (I think the term was lumen, I could be wrong on that).
I bought them second hand from someone who had them to light his own driveway. What I saved in lights I can see I am going to need for poles and wiring. But it will be so worth it in the end!
Thanks for your help!!