The mini rings photo on the campaign page is a 20 times blow up. If there is anything that your bare eye can detect, this photo should capture it. This is about the best we can achieve without lens modification. We do observe inconsistent surface smoothness for different printed rings, and it may be caused by the material stress. The ring with 10mm diameter has a material volume of only 40 mm-square.
The accumulative stress may not be high enough to cause relaxation. Please remember that the resin is still reacting even after the light is removed so shrinking is a continuous process during printing. To further improve the smoothness at high resolution, using the right type of resin is key. Low shrinkage is very important, otherwise, you could see the horizontal lines pop up when the cured resin relax its accumulative stress. Softer material may delay or prevent sudden relaxation of the material. Supports also have impact on how the cured resin moves after relaxation. This is the most likely reason for the occasional lines you see.
Please share your thoughts!