I'm going to be getting into aerial photography of properties, buildings and homes. Is there anything in particular to keep in mind when shopping for a camera and lens?
From my somewhat limited experiences taking pictures out of my friend's Cessna, I can recommend the following:
- The camera body itself will not make a huge difference here. You may consider that most brands create better lenses for their professional bodies (in Nikon, D700, D3) than they do for their prosumer bodies (in Nikon, D300, D5000, D90, D3000, D40, etc), so if you can afford it and you plan to use the camera professionally, you may want a higher-end body. Other than that, the camera is much less importan than the lens itself. Also, brand is a non-issue here.
- Buy the best telephoto zoom lens available for your camera body, with 2.8 flat aperture and vibration reduction or image stabilization. Since you'll be in a fast-moving vehicle, you will need the shortest exposure times possible, and that can only be achieved with professional lenses. Save the slow 70-300 f/3.5-5.6 for ground shoots on sunny days. It will cost a lot of money, but presumably you'll be taking these pictures professionally, so consider it the cost of doing business.
- Do NOT let the lens touch the window pane when you are shooting. That transfers all the vibration of the vehicle directly into your camera.
- Buy a circular polarizing filter. You'll notice that unless you have the clearest of days, there will be smog and haze in your photo. The circular polarizing filter will cut through that and allow you to shoot in more marginal conditions.
- This may sound silly, but make sure the plane you're flying in has a clear window to shoot out of, and ideally a clear window on both sides of the plane. You would think this is a non-issue but I've seen some pretty streaky small-plane windows, and that makes autofocusing all the more difficult and you end up doing a good bit of work post-processing the streaks out afterward.
I have to disagree with a few things Naseer said. The camera body can make a difference. For example, the added inertia of a heavy pro body can keep it steadier and the vertical grip and larger body can make it easier to maintain a solid grip on the camera. Also, Nikon makes an equivalent to their pro full frame lens (24-70 f/2.8) for their APS-C cameras (the 17-55 f/2.8), so in some cases at least, you can get pro glass for the non pro bodies. Also, the 70-200 f/2.8 works fine on their APS-C cameras. Either way, we don't know what gear you have, so I won't continue on here about that.
Next, better than shooting through a clear window, find a plane where you can open the window or even remove the door. This will be the case in some small planes and you won't be at an altitude where the plane will be pressurized anyway. It's an option you should keep in mind. Maybe better, shoot from a helicopter. Many choppers have windwings (like some planes) you can open for ventilation and you can shoot through those, or remove the door altogether.
For the absolute best picture quality, you may want to do things such as shooting at your camera's base ISO (e.g., ISO 80, or 100, or 200), and the optimal aperture for the lens you're using (e.g., f/5.6 or f/8). In these cases, you might end up with a lower shutter speed than you'd like, especially when you consider vibrations from the engine, or shaking from turbulence. In this case, you should consider using a gyroscope.
If the photography is for documentary purposes, then all of this is probably overkill. If it's for artistic purposes, you'll want to seriously consider all of the above (and Naseer's suggestions).
Oh, one last thing. If you're shooting through glass, use the polarizer to help reduce reflections. I'm not sure how this will work with the plexiglass windows of aircraft, but keep it in mind.
Not being an aerial photographer myself, I can't be certain that I've covered everything, but I'd say using very fast lenses from 200mm on is probably key, as there will be a lot of vibration from whatever flying machine you use so faster shutter speeds will probably be required, and most buildings will be quite small viewed from above so will need proper magnification.
If you're going to be taking photos at night, then you will probably also want a body that can produce good-quality pictures at high ISO values; generally the full-frame bodies (e.g. Nikon D700, Canon 5DMkII) are best at this.