Some fixtures (eg Eclipse Fresnel) has parameter labelled "Intensity Mode."

In the case of this fixture it seems to be the dimmer curves.

Those are the 5 options in Eos:

This represents those dimmer curves (screenshot from the fixture's manual) in the fixture menu:

Yes, it does answer the question. Thanks.

I searched through the manual without the success you had. Very grateful.

James

Looking at the manual for those fixtures it says "Preset dimmer speed from display menu" - which to me indicates that it is grabbing the setting which was defined on the fixture itself but you can change the mode to off/fast/middle/slow. Unfortunately when vendors use this sort of labeling in their documentation, you end up either having to guess and try, or see if further information can be found in the lighting fixture documentation on what exactly that means, how to change it, and what the other settings really do. 

Looking at the manual for those fixtures it says "Preset dimmer speed from display menu" - which to me indicates that it is grabbing the setting which was defined on the fixture itself but you can change the mode to off/fast/middle/slow. Unfortunately when vendors use this sort of labeling in their documentation, you end up either having to guess and try, or see if further information can be found in the lighting fixture documentation on what exactly that means, how to change it, and what the other settings really do.