Yea,
Here in Kansas the Sun is getting lower and my two VFT'S that are on the kitchen windowsill are getting a dose of Sunshine that they haven't had for awhile.
Spring and Fall, I keep them on the sill. During the Summer; I give them a dose of sunshine outside three times a week. Growing them outside isn't an option for me. I have 50 VFT'S under flourescents right now and they aren't worse for wear; in fact they look great! I've been selling them to customers at my Jewelry store. I'm reducing the amount of light for them by one hour increments each month to simulate dormancy. Also the room is cooler now as well.
I agree that Direct Sunshine is better than artificial; but indirect isn't. My VFT'S have had spindly growth with natural ambient,not direct light. I put them under flourescense now.
Variety has a play though; as the big mouths didn't mind the lesser light; it was the Green Dragons that were getting spindly with smaller traps in the indirect sunlight.
Outside on a cloudy day is at least as good or better than artificial; as there is no glass to filter out any rays.
You need to know that you have options. You don't HAVE to grow them outside. Outside has alot of disadvantages for me (unless I build an expensive green house which our Spring storms would certainly destroy).
We are semi arid so spider mites are in great abundance. We have squirrels, birds, etc that love tender VFT'S. The list goes on and on. I can really get close and enjoy my collection in my basement under the strong flouresent lights. I can monitor their health. A screened patio would be perfect, but I don't have the space in our backyard. I am entertaining the idea of building a cold frame attached to the house; you know, kinda half of one with a door on the side, but still; I'm not one that can plant em' and forget em'. I have to stare at them up close; they simply fascinate me!
There are disadvantages of growing them inside as well, you have to really watch your watering on how much; letting them get cool damp before watering again and not letting them stew in water all the time or you're asking for fungus; the list goes on as well with one being I feel compelled to give them a spritz of miracid/superthrive on the foilage once a month for lack of insects.
There are people here that insist that if the plant isn't outside; it's next to suicidal for the plant; I'm here to say that simply isn't so, or you'd lose alot of people in this hobby.
I've got VFT'S I've had 6 years that I've divided three times now that have never seen the 'light of day' (natural sunshine).
Huge traps as I have them within 6 inches of the light where they receive warmth as well.
However; it is MUCH simpler to grow them successfully outside!
Phil's Green Dragons, by the way, are the hardiest VFT cultivar I've seen in my collection. They are rather forgiving; more so than the commons, but they do like alot of light!
My Dente' looks fine under artificial as do the big mouths.
The commons seem more prone to viral or fungal problems growing them inside in artificial, so I have to watch them.
Good luck.