How do I prevent my iMac from dimming on its own?

What settings have you tried exactly?

The setting for dimming should be the one in Settings ➜ Displays ➜Automatically Adjust Brightness. Turn that off, so it's not dimming the display if ambient light changes.

It will still dim the display after a period of inactivity, ie no mouse movement, no keyboard presses and no action happening on the screen like a video or movie playing, and if it continues with no activity it will eventually turn off the display.

You can control the time it waits before it turns off the display entirely in Settings ➜ Lock Screen ➜ Turn Off Display when inactive.

sheabruhhh wrote:

My IMac desktop keeps dimming regardles of setting changes. I've tried everything but it continues to dim on it's own. How can i fix this issue?

[Re-Titled by Moderator]

Original Title: IMAC DIMS ON IT'S OWN

I know you've said "I've tried everything", but Check your battery settings:

Change Battery settings on a Mac laptop - Apple Support

sheabruhhh wrote:

It doesnt have battery settings, only energy and no settings there for me to adjust anything

when i shut down my imac it goes back to regular lighting but after 5 mins it goes back down and i work from home so my computer is usually not idle.

Oooops, sorry. I misread your post. Hopefully you'll get your issue resolved. Sorry again.