Only up to 10°. At very close range this 10° with its rectangular tight spill already creates some artifacts, the 5° will be worse I guess. The narrow spill is very useful in cases such as mouth or nostril inspection where you don’t want too much glare to the patient. I myself prefer the 20°. The stock optic has bad yellow tint shift ring around the hot spot.
I have tunnel vision, field of view well under 10°, so I’m always on the lookout for lights that put all the light where I can use it. 10° would still be pretty good, though
UPDATE181221: Maukka calibrated Jetusolis
If you guys interested to make a calibrated light using this Jetusolis, you can ask Maukka and check this thread:
The pricing for Jetusolis:
1 - 3 pcs = $28,5/pc
4+ pcs = $27/pc
Of course if you don’t need the data, just order from Clemence when he makes them publicly available in his store. No reason to include an extra step in that case.