Maybe you think that a 0.35mm nozzle is much more accurate than a 0.50mm nozzle. In fact, I think yes and no…
When comparing the path of the nozzle between 0.50mm and 0.35mm you will find that a 0.35 mm nozzle provides only very little improvement in the corners. In image 1 below, it can be seen that a 0.35 mm nozzle printing a 90° corner, only improves the angle sharpness by 0.03 mm. The red circle correspond to a 0.35 mm nozzle and the blue circle with a 0.50 mm nozzle. As a comparision, next to it, you can find the min and max sizes of an human hair (in grey).
Image 1 Top view of nozzle with extruded filament path.
Only certain parts with very sharp edges and / or very thin wall will be improved through the use of a 0.35 mm nozzle. In most other cases the improvement is only minimal. In addition, a 0.35 nozzle covers an area of 9.6mm ², which is less then half of a 0.50 mm nozzle which has a coverage area of 19.6mm². This results in depositing less than half the material at each pass and thus doubles the printing time.
Another point where a nozzle 0.50 is interesting is when printing very angled shapes without support. In the images below, we compare the different nozzles for the same print where the slope is 30° and the Z layer height 0.15mm. Image 2 Printing with a 0.5 mm nozzle at an angle of 30°. A 0.50mm Nozzle covers 0.24mm, close to half of the diameter.
Now same part with a 0.35 nozzle : Image 3 Printing with a 0.35 mm nozzle at an angle of 30°. Only 0.09 of the previous level is covered by the 0.35 (at same Z level step).
One of the conclusions we can draw here is that in some cases the print results with a 0.35 mm nozzle really can be less acurate.