Wayyy more resin/trichome production outside???

So I am working with several different strains. Both have been grown inside and outside. I am pretty far south and I have noticed that there is way more resin/trichome production outside than inside. I feel like this must be because of the added UV and other spectrums of light. I will be adding some UV lights inside to see if I can obtain similar results. What do you guys think?

seems logical also lower humidity is supposed to play a part, possibly its less humid outside?

Nope it's actually quite humid here. The size and number of trichs are much better outside for sure. I imagine that running hps, halide, and uv light during flower would be the closest you could get to outdoor conditions. The ceramic metal halides look promising as well.

Hell why not add in some Led's. I think it would be cool to see the results of all of the light technologies combined.