At the 3DEXPERIENCE World 2024 this week, a Trimech team member from UK asked about the differences between High quality image and Ultra in my breakout session on 3DEXCITE Product Communicator  on Monday. 

I wasn't sure and guessed it was related to Pixel Per Inch (PPI). 

I was wrong. PPI is controlled by the resolution settings. 

Quality here actually presets the number of sampling steps, which help in determining how light interacts with objects, the color of pixels, and how to accurately represent textures, shadows, and reflections.

From Preview to Ultra, the render time and credit costs go higher, as the sample steps increase.

A rough estimate is that High quality suffices in most cases, while Ultra may be needed for large poster printouts. 

The Online Help actually provides an illustrative comparison between various qualities. 

Let's take a detailed view of a phone as an example. 

Preview

Medium

High

Ultra

Hope it helps. 

Thank you again for the question, Team Trimech! 

Sorry that I forgot to take your card. Would love to connect if you see this post.