Before you go to an air show: Do a little research. Google air show photography and you will get a tons of sites. I did and some of the best information came from a person who was using a film camera and had done it for years. Yeah, I know, film; but the skills of digital and film are the same, just how you achieve them differs.
One of the things I learned is to get there early and get a spot near the end of the runway for the best shots. This is where they will land and take off and do steep climb outs at. If you are in the middle of the runway area, you will get a lot of bottom of the plane shots, not too exciting. Getting a spot at the end of the runway is easier anyway. Since you probably will only have access to one side of the runway, the middle means you have only one spot everybody thinks they want and are fighting for. One the other hand, there are two ends of the runway so you have twice the chance of getting a good spot.
Equipment: I don't mean to sound like a snob but it takes some decent equipment to get a decent shot. For still photos, I used my Nikon D300 with a 17-55 f/2.8 lens for static displays and my 80-200 f/2.8 for flying shots. Why f/2.8 lenses? Outside, it wasn't necessary but inside hangers (especially on cloudy days like I went on) and photographing dark areas like the torpedo bay of a WWII dive bomber or inside the bomb bay area of a B-2 bomber, it came in great as as a single slash unit simply won't go far enough for the large areas involved (ground to cockpit of a B-17 for example).
I also took my P&S Canon 210SX for its movie feature. Unfortunately, it didn't work too well. I didn't have a tripod or other means of stabilizing the camera and when you zoom all the way out with a P&S, any movement of the hands or fingers produces great swings in the image. The further away the aircraft (or any target) and the more you have to zoom, and the worse the effect is. As fast as the planes were moving and without an optical viewfinder (ggrrrr - is any P&S maker listening?) it was almost impossible to acquire the plane and track it. The glare on the LCD screen made it difficult to find and track the plane and the slightest movement of my hands produced video that would make Popeye seasick. The DSLRs with optical viewfinders and larger bodies are that much easier to hold steady and to find the image with.
Camera phones. Yes I saw a few people using their camera phones (not even iPhones which have a decent camera in them) and all I could do is shake my head. What they got ware little black dots against a sky. Don't even go there. Bottom line, a DSLR is the best camera for this job, period.
Circular polarizers. Great idea, lousy to implement. Things simply move too quick to use. For those that have never used a circular polarizer (DSLRs need circular models as the lenses rotate), the problem is they have minimal effect when pointed toward the sun or directly away form the sun and have maximum effect when pointed 90 degrees to the sun (ie, the sun is to your left or right). This is why you can't use a really wide lens setting (say 24mm) with a circular polarizer as it will be dark in the middle and light on the ends as the field of coverage goes beyond right angles to the sun and starts to pick up being pointed a little more toward the sun. And like I said, it happens too quick to adjust the polarizer. By the time you adjust, the aircraft have moved on, waaayyy on.
Lenses: A 400 mm reach would be nice. My 200 mounted on a D300 has an effective lens reach of 300 mm. I won't get into explaining her. EMail if you want.
Empty your camera bag: All I took was the camera, and the sling case for the big lens. ITs too easy to set a bag down and forget it or have somebody walk off with it. Besides, you simply don't need every piece of equipment you have. Go Light!!
Equipment settings for flying shots (Static displays you can do normally): Shutter priority with High shutter speed. I used 1/250 sec and is want' enough for a lot of shots. Think 1/400 or 1/500 at least. Don't worry about aperture, the only thing behind the aircraft is either the sky or trees if they are flying low. A shallow depth of field will blur the background so who cares about the sky? And the trees will be blurred anyway as you pan tracking the plane from one end of the runway to the other. So don't worry about aperture, go for the shutter speed.
NOTE: When photographing propeller planes, drop the shutter speed down or the propeller will be frozen and the plane will look like it s propeller isn't turning, a most unnatural view for an aircraft in midair. 1/100 ought to do the trick. My problem? I got so wrapped up in the action, I completely forgot. Oh well, next year will be another chance.
Ok, lets look at some photos.
An old WWII Navy Bi-plane. No details but it looked great and colorful.
B-52 bomber. I had to really back up to get all of it in the photo and I had a wide angle lens on! The wingspan on these things is incredible. Notice the struts with wheels at the end of the wings to support the wings when needed. (I presume when the wing fuel tanks and full and ordinance is loaded on the wings. You can get a feel for the size of the plane by comparing it to the people walking near it.
BTW - I had trouble on some shots simply due to the wing blowing me around.
I think that's enough for now. I will post more photos later.