Aerial photography with Michael O'Brien

Horizontal Falls, from the air. Picture: Michael O'Brien

It's an ongoing source of frustration for a photographer, when the holiday images you've taken don't match up with the memory stored in your mind's eye. This frustration is particularly pronounced when it comes to aerial photography - no wonder, with so much working against you.

I've just returned from a flight around Derby in the Kimberley and, for a photographer, this part of the world throws up most of the problems you're likely to face when photographing scenery from the air.

Be it a fixed-wing, seaplane or a helicopter tour, your biggest demon is going to be camera shake. Techniques that prove to be sound on terra firma hold little sway when a Cessna engine is making your bones rattle. A shutter speed of a 1/1000th of a second isn't always a guarantee of success, particularly when shooting from a moving fixed-wing aircraft. Fixed-wing pilots are adept at slowing down their air speed when you've reached your target and choppers can hold a relatively stationary position, all of which helps - but don't be fooled, there's still a whole lot of shaking going on.

GALLERY: See Michael O'Brien's full set of Kimberley aerial photographs, complete with informative extended captions with tips and advice.

To address this, increase your ISO setting and be bold. Most cameras can comfortably handle a higher setting without compromising quality.

You now have extra exposure "stops" to play with, which brings me to my next point - your (possibly inexpensive) lens. A lens not being used at its optimum aperture can result in some serious quality falloff at the edges of the frame. Aircraft movement can exacerbate this problem. As with all exposure equations, we're dealing with a combination of shutter speed and f-stops (aperture). For aerials, we need to share the love between both. Split your additional stops between our first problem - shutter speed - and the second problem, lens quality. With our increased ISO, increase both your shutter speed and your f-stop number.

On my flight, in partially overcast conditions, I set my ISO at 640 and shot at 1/1250th of a second at f8, give or take to allow for changing cloud cover. These settings enabled me to comfortably use a 70-200mm lens without having to be too concerned about the issues I've raised.

Some problems are simply beyond our control. The best aerials tend to be shot mid morning on a cloudless day. The sunlight gives objects on the ground much sharper definition than what you'll see on an overcast day. Also, in the morning the humidity hasn't had a chance to build up. Shooting through excessive humidity gives your images a milky, flat appearance. The further towards the tropics you travel, the worse this issue becomes. The other factor that's generally beyond your control is the altitude of the aircraft. The lower the altitude, the less humidity you'll be shooting through.

Patchy cloud cover is also undesirable as it puts a mosaic of shadows over your image and unless you can change the day of your flight, is unavoidable.

The aircraft itself can pose problems. Even shooting with my 70-200mm lens, I had to be aware of reflections on the window I was shooting through. The wider the lens you use, the more reflections you'll be dealing with. For this, it's a simple case of see and avoid.

There are some problems that can be corrected in Photoshop and I've used those techniques in these images. By adjusting levels to beef up the contrast I was able to counteract the overcast conditions. The other issue was the window tinting on the aircraft. It's a little trickier to get this right but careful use of the hue/saturation control can overcome the colour cast caused by tinting.

In this litigious day and age, it would be rare to find an aerial tourist operation where you aren't sitting in an enclosed cabin. But if you do find yourself shooting out of an open window or open-sided helicopter, be absolutely sure you've stowed all of your loose items. Lens caps can be tricky at the best of times but a lens cap finding its way into an aircraft engine can be catastrophic, so have your lenses and caps all worked out before take off.

So now that I've got you safely back on the ground, you can reminisce about your flight over the spectacular Kimberley scenery as you view your equally spectacular aerial photos.