I'm usually happy making lights etc glow using 'super-ambient', but there is an undocumented limit. The surface brightness does not increase if dialled beyond a dozen or so. This is not a problem if you have 'luminaires' with a large surface area, like ceiling-panel lights. It is a nuisance if skinny 'strip-lights', exasperating if pendant bulbs or wall sconces. The latter may need lonnnng renders to accumulate enough virtual photons...

( Else, Plan_B, hiding new Poser point-source lights within... )

Oddly, none of the Poser gurus seem prepared to discuss this limit. I get feeling 'super-ambient' facility may be a 'legacy' feature, or an accidental oopsie like 'cross-talk' that proved useful. And, in subsequent versions, may be quietly deprecated then lost...

The second route is to pull-on your mail shark-suit, buckle your weight-belt, check your twin SCUBA tanks and pony-bottle, plunge into Cycles...

IMHO, Pp_11's Cycles UI makes using it hard work. Lists should be alphabetic beyond first few 'handy' options. There should be a 'directory', and there really, really should be a map.

Okay, rant over.

After brisk discussion at Rendo', and ingestion of sufficient caffeine via several mugs of 'Builders Tea', I've learned the basics of how to get 'Emission' working.

There are two 'gotchas'-- Okay, three.
First, 'Cycles' is much more powerful and complex, this is but the 'kindergarten wall'.
Second, Cycles UI is seriously unfriendly, see rant above.
Third, the FX only shows up when you render in Superfly. So, lots of test-renders.

Okay, you need two test-subjects. I'll use the default prop 'box', usually found in Poser Primitives between 'Bowl' and 'Cane'.
Load one into scene, move it along a few feet. Load or duplicate another. Position handy...

First way: Super-ambient
Go to Material room, click on first prop box in mini-window or object list.
Select 'advanced' tab. Should now show 'Poser Surface' list.
Set 'Ambient Color' to taste, usually a light hue.
Set 'Ambient Value' in range 1~~10, which should bring up a nice glow.

Second way: Cycles' Emission (very basic)
Go to Material room, click on second prop box in mini-window or object list.
Select 'advanced' tab.
To right of 'Poser Surface' list, there should be an empty gray area between list and too-skinny scroll-bar.
Right-click there. Menu pops up, 'New Node'.
Follow this right via Root to 'Cycles Surface'. Left-click on this to select.

Right-click in the empty gray area below this small, new list.

Menu pops up, 'New Node'.
Follow this right via Cycles, Shader, Emission. Left-click on this.

Left click and drag the white Emission spot-tab onto the Cycles Surface black spot-tab.
This should create a link or channel.

In Cycles Surface list, left-click the Superfly Root tick-box to enable it.

In Emission list, set Color and Strength to taste.
Test-render in Superfly, iterate until satisfied...

Low values of 'Super-Ambient' and 'Emission' are similar brightness, but 'Emission' does not max-out, may be dialled to 'bleach'.

Have fun !!

   Thank you kindly Nik, I didn't even realise there was a limit!