Automation: trigger when light turns on without brightness

Hi there.

I am struggling to find a trigger/condition for a light entity. It shall be triggered when the light is turned on and there is no explicit brightness information.
The goal is to set brightness to 100% whenever I just turn on the light. But when I directly switch the light to 50% brightness, the automation shall not be triggered.

I tried to use a trigger with platform: state and also with platform: event / event_type: state_changed. So far every event had the brightness information included even when I had just turned on the lights.

Any ideas how I can get the trigger working?

I dont think there is an easy way todo that as there will always be a percentage and state on/off when you turn on/off a light.
You can however filter on who turned on the light. Will that help with your use case?

Thank you for your input. Unfortunately that would not help because I could still not differentiate between a light that just got turned on and a light that was sight to a special brightness.

Nonetheless I think I have found it. Maybe I was just too blind to notice earlier on. I have found this:

event_type: call_service
data:
  domain: light
  service: turn_on
  service_data:
    entity_id: light.wg_eg_buro_deckenleuchten
    brightness_pct: 85

The brightness_pct is not there if I just turn on the light. So that should work. I just have to do some tests with it.

So far it seems to work. In case anyone stumbles upon this in the future: My (final?) condition now looks like this:

condition: template
value_template:
  "{{ (trigger.event.data.service_data.profile | default(none) is none)
  and (trigger.event.data.service_data.hs_color | default(none) is none)
  and (trigger.event.data.service_data.xy_color | default(none) is none)
  and (trigger.event.data.service_data.rgb_color | default(none) is none)
  and (trigger.event.data.service_data.rgbw_color | default(none) is none)
  and (trigger.event.data.service_data.rgbww_color | default(none) is none)
  and (trigger.event.data.service_data.color_temp_kelvin | default(none) is none)
  and (trigger.event.data.service_data.kelvin | default(none) is none)
  and (trigger.event.data.service_data.color_temp | default(none) is none)
  and (trigger.event.data.service_data.color_name | default(none) is none)
  and (trigger.event.data.service_data.brightness | default(none) is none)
  and (trigger.event.data.service_data.brightness_pct | default(none) is none)
  and (trigger.event.data.service_data.brightness_step | default(none) is none)
  and (trigger.event.data.service_data.brightness_step_pct | default(none) is none)
  and (trigger.event.data.service_data.white | default(none) is none)
  and (trigger.event.data.service_data.flash | default(none) is none)
  and (trigger.event.data.service_data.effect | default(none) is none)
  }}"

This will check if any predefined value for color and/or brightness is set. Only if it is not set, the condition will be true.