Even through a camera viewfinder it's a bad idea, so watch out for your eyes if you're going to try to capture something like this.
Maybe it's easier to shoot the planes at the Battle Creek Air Show and Balloon Festival during the daylight hours; I went later in the day to watch the balloon launch and illume, so when it came to plane action I found myself shooting towards the setting sun. The picture above is real color and representation - the canopy bubble reflected that very bright glow. No enhancement. The only thing I did here was to add grain, simply because this angle and bright light picked up every. single. piece. of dust on the sensor and/or/in the lens, and I didn't feel like spending a day trying to clone it all out.
Anyway, if you are looking for something to do in southern Michigan this weekend, this show offers a lot for a very reasonable price. They have your typical carnival rides and games, food booths, hands-on displays and crafts for the kids, non-stop action in the air (weather permitting), and fireworks too. It's not something I personally want to do every year (not big on stunt planes), but I'm glad I went once for the experience. Check it out if you get the chance.