Ok, lights, time for a new lesson.
First you need to know that light emitters emit light in the direction of the normals of the mesh. So a one sided plane has one side which emits light, a 2 sided plane emits light in 2 directions, a sphere in all directions.
When you create an emitter from a Poser spotlight, it will create a one sided plane parented to the spotlight. You can control the direction by rotating and moving the Poser spotlight. The one sided plane will follow.
If you look at the material of the material of emitter, you can see it is a Diffuse materal with an Emission section. There are 2 types of emissions: Black Body and Texture emission. Black Body emission uses the temperature in Kelvin to define the light. See https://en.wikipedia.org/wiki/Color_temperature
for a list of this with its color. The texture value and power here are multiplied and define the strength of the emission.
For Texture Emission the texture node defines the color of emitted light and is multiplied with power. No matter the texture color, the light will be white very soon if you increase power. It is very useful if you have something like a tv screen. Set up the texture node with the screencap of the monitor and set the power very low (less than 1 normally) and you will have a tv screen which emits a little bit of light.
Surface brightness on makes an emitter independent of its size (mesh size), double sided on overrules the normal direction settings and emits the other side as well.
Sampling rate defines the importance of the light - increasing it makes the render use more samples for it. Visible on or of on Diffuse and specular defines whether the light is seen on diffuse or speciular/glossy materials (normally you have these enabled).
Transparent Emission tells the render engine it should cast light even if the opacity is set to 0 (completely transparent). Cast Shadows Off turns off Shadows.
The distribution Node is the interesting one for how light is distibuted (falloff,, sharpness, etc).
By default lights, are emitted in all directions from each normal (so 180 degrees). You can control this by using IES distribution maps. An IES map is an industry wide standard (with CG and in the real world) to defiine how lights behave. See a tutorial on this here: http://www.cgarena.com/freestuff/tutori ... ieslights/
Load an IES map (RGB texture node) in the distribution node. Set the gamma to 1. Now expand the projection node for the texture and set the coordinate space to Normal Space. (This is REALLY important otherwise it will not work)
That is it.
That tutorial link tells you have to look at the maps and how to create them. In this link https://support.solidangle.com/display/ ... tric+Light
there is a link with a set of very nice IES lights. Download the sample picture of it as well, it is handy to have to know what each of the IES maps do. Number 29 for instance is a nice spotlight with defined soft edges.
You can find IES lights in lots of places, just google them. You can often download them from real world lighting manufacturers as well.
Configuration: Windows 10 64bit Creators Edition, I7 6850K, 128GB, 2 GeForce 1080ti, P11 Pro SR6