Whenever I shoot still objects (not moving at all) like buildings or parked vehicles I use a technique called HDR photography. HDR stands for High Dynamic Range.
Modern digital cameras already have a fantastic dynamic range. This means they are able to capture very bright and very low light. In photography terms this is called ‘highlights’ and ‘shadows’. Due to the digital format, in which cameras store data (numbers) there must be a defined threshold of absolute white and absolute black.
In certain scenarios the dynamic range of a camera (in my case a Canon 5d mk3) might just not be enough to capture the complete spectrum of highlights and shadows that we can see with our human eyes. Highlights such as clouds or white objects might be ‘blown out’ (completely white) and shadows or black objects might be completely black.
Have a look at this image:
It seems to be correctly exposed however if you look closely to the very bright and very dark areas you can see that these are either completely white or completely black. There is hardly any detail in some parts of the clouds, the window frames or the shadows of the bushes.
In order to compensate for this I take two more photos: one deliberately over exposed and one underexposed.
In post-production I can merge these three photos using special HDR software. The HDR algorithm merges the highlights of the underexposed and the shadows of the overexposed photo into the correctly exposed image. The final HDR photo is therefore a digital composite of three exposures. There are no blown out highlights anymore (check the clouds and the window frames) and there is plenty of detail in the shadow of the bushes and trees. This is the completed image:
HDR photography requires a tripod to allow for perfectly aligning of all images later at the computer. It also takes three times the amount of date storage on the camera’s memory card.
I use HDR whenever I can. If you have any questions feel free to get in touch.