+1 to what Laszlo recommended. Visit here:
http://www.artlantis.com/_forums/index.php
Be sure to state what version of Artlantis Studio you are using in order to receive appropriate help there.
What you describe, though, is the preview window taking a long time (blurry) to display an approximate illumination preview with your lights on. That suggests that you have either or both of these issues: very many lights (including neon) - or a computer without enough horsepower. Artlantis will use all cores available, and a 4 core or higher processor is highly recommended.
One of the forum moderators
AC 28 USA and earlier • macOS Sequoia 15.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB