I planted an Australian fern tree that had been sitting in a pot for a few years in the backyard a couple months ago. I had always read and assumed that they were shade loving things so i planted it in a deep shade under a canopy of cabbage palms. But in the short time since then i have noticed a few big fern trees that were taking a lot more sun. Stopped at top tropicals b farm in Sebring that has a huge one taking straight sun and i noticed another person nearby put their's over a wall to get it more sun and I'm wondering if I've made a mistake. It's hard to say because when the sun tips during winter it will get some more sun, but in summer not much at all. I don't think it's worth moving now, but i could...

Most of ours in Lakeland are under oak canopy with dappled light. That seems to be the best spot for them here.

Shade is best when they're young. Assume that's Sphaeropteris cooperi?

The three native species here in Tasmania all start their lives in shade but can grow as emergents as they mature. The species I've seen on the mainland, including cooperi seem to do the same.

I was super surprised to see small Cibotium glaucum (I think!) growing in full scorching sun amongst the lava flows in the bottom of a crater in Volcanoes NP in Hawaii, pretty extreme environment for a tree fern!

As a young fern they like dappled light and water, but as soon as they get a metre or two sized leaves they take a lot of sun. I use them as canopy trees in harsh areas around my garden. Great pioneer plants for establishing a garden. And once they get a couple of metres of trunk full sun not a problem. They do like a drink but once established they are tough plants. Just plant as many as you can anywhere you will be surprised how many live, you may lose one or two out of 20 or so, once they get growing they are rocket ships.

This one has been in the ground for about 6 months from a 140mm container, just add water they take off!

Florida sun is tough on them, combined with sandy soil. They can take sun if they have enough water but aren't tolerant of dry, hot, and sun all at once. Shade isn't a problem at all, you'll just get less compact, probably nicer looking leaves. Maybe a bit slower growth overall, just like a palm. Winter sun/summer shade is actually perfect.