Totally normal.
You are correct that the camera auto exposure was trying to adjust to the different brightness on the screen. Over dark Forest, it brightens up, and when looking at bright sky, it darkens.
If you touch nothing, the camera adjusts for the average brightness on screen, or, tries to. It guesses what you are intending to shoot based on what is most on the screen.
Manual settings, adjusting shutter speed and ISO will help you find a fixed setting, but as you noticed, not so great when flying between scenes.
What you can do, is TAP THE SCREEN where you want the camera to adjust for (called metering). A yellow circle will pop up where you tap. The camera will now adjust for that spot. You can do this easily while flying, you can tap to different points, and you can even cancel it.
As far as exposing to both sky and ground at the same time, that really won't happen in video on the spark. The ability to adjust for highs and lows is called dynamic range, and the Spark camera has a very narrow range. If shooting a still photo, you can fake a High Dynamic Range by using exposure bracketing, which takes 3 or so pictures, all at different brightness (called exposures). You then merge them later on your computer (using Photoshop or similar), and then you can adjust for both high and lows.
Hope this helps.
I was out today in (above) a really beautiful forest and my camera is set to auto and infact I have never touched the settings as I am no photographer and don’t know what I’m doing! It looked as though the camera was trying to self adjust and get way to dark where it was hard to see detail,I would move the gimble down and it would get bright again,the last time it got dark I stopped the spark in the air went to camera setting and the iso I believe? that was set in the middle so I turned that up and that did the trick but then when it brightened up it looked really washed out! Is this normal? Should I forgo the auto settings and read up on how to adjust manually? As a note it was about 5pm and fairly sunny,two pics from the same vid,thanks in advance!
