Thinking differently three times over

I've always been keen to try something different and to learn something new so the challenge of HDR photography was right down my street.

With digital photography, when we meter on a subject all we do is get the exposure right for the aircraft itself, there is nothing wrong in that except by doing so we miss the detail in the sky beyond for the simple reason that the sky is over exposed. Like wise, if we are in a hangar with a light behind the aircraft, the light streaming in through that window over powers the light meter and under exposes the subject. Correctly metering on the subject blows the highlights in the window and that detail is lost forever to be replaced with large blocks of white.

High Dynamic Range (HDR) photography aims to improve on the short comings of a digital camera by combining the best in a number of photographs to try and achieve what the human eye does naturally. HDR uses an image exposed for the details in a window or sky at the expense of everything else in the picture, an image where the mid-tones of the subject are correctly exposed at the expense of the sky (a normal photograph to us) and an image where the detail in the darker shadow areas is recorded and everything else in the picture is overexposed.
Typically this means exposing three images one at +2EV, one at 0EV and one at -2EV. (EV is exposure value and can roughly be thought of as "stops" or in my case an equivalent increase in shutter speed.)

These images are combined in a mathematical way to produce an image that has the best of all worlds.

One added benefit if HDR is an increase in the Depth of Field made possible by the combination of exposures, however HDR is not without its drawbacks, for one it is very heavy on computing resource and the finished article sometimes suffers from un-natural looking, over saturated colours or a halo effect around objects in the picture, however in most cases these pitfalls can be overcome to produce an acceptable image.

Photoshop CS2 and CS3 has a HDR program, (FILE, AUTOMATE, MERGE TO HDR) if you want to give it a try but the output is very difficult to work with and more often than not for me produces a useless image.
There are a number of specialised programs on the market for HDR imaging, amongst which is Photomatix and one that I discovered Dynamic Photo HDRi by Mediachance. You can try a limited facilities version for free and is the same one that I used to produce these images. http://www.mediachance.com/hdri/index.html

Compare this photograph, exposed just for the R44
to this HDR version taken a few seconds later
the detail is there in the sky and the colour of the grass is much richer.
The interesting thing about this photo was it was made from three separate RAW conversions from a single image, now that does have possibilities.

The detail in the window is totally lost and some on the fuselage itself.

With HDR, there is detail in the window behind and also on the Baby Ace


The detail in the hangar roof and through the windows is there and so is the detail that would have been lost in the shadows, especially so with the photo shot against the hangar door.


Cambridge In Colour has an excellent explanation of what HDR photography is all about.
http://www.cambridgeincolour.com/tutorials/high-dynamic-range.htm
It is an excellent web site and resource in its own right.

One could say that there is nothing wrong with our photographs as they are and I for one would have to agree however this is a tool that gets the best out of our photographs and a tool that should not be left in the tool box to go rusty. I'll be using this technique again that's for sure.
Lastly, I have to thank my friends at Perth Airport for allowing me the free run of their hangar, remember to ask before entering a hangar.