[Fernando Tella]

What you are doing Ernesto is reducing the steps of gradient so you'll notice how it will "jump" from one step to the other. Notice that with 8bits image you only have 256 steps (from 0 to 255). Using a 16 bits greyscale map will improve the result. Just make a new image in PS, make it 16 greyscale and redo the gradient.

[Ernesto]

The clipmap is not so much the issue, the graduation of the 32bit emitter is what you need to fix. Mihai and Fernando have already explained this..
Remember your screen is only 8bit (at best) so you cant see the intensity of the 32bit data, but you can adjust that intensity slider back and forth in Photoshop to see the full range of intensity in the hdr emitter.

It is not an HDRI emiter, but a plain emiter

E

[eric nixon]

Then you must make a hdr emitter, just a gradient in PS will do. Good luck (not sure if gradient tool works in 32 bit, but it works in 16bit, then convert to 32 and adjust gamma to suit)

[PA3K]

And what about emitter colour temperature gradient map (293 to 1400 Kelvin). It will be more physicaly correct. Also intensity (Watts) should be linked to heat capacity of the used material. But there is no option to do that in Maxwell...

Patrik