This was one of those images which came about by accident. A image which on first look didn't really do much to excite me. It was simply an image of two people. At the time I was trying to capture the couple as a silhouette with the brightness of the street in the distance. As is often the case though the image didn't match the plan. The whole shot was completely wrong. The street brightness and details were over exposed and blown out and alley was almost totally dark.
I always take my images in Raw mode. What is Raw mode or the Raw format? For the uninitiated - "Raw mode is a file format that captures all image data recorded by the camera sensor when you take a photo. When shooting in a format like Jpeg, the image information is compressed and lost. Because no information is compressed with Raw you're able to produce higher quality images, as well as correct problem images that would be unrecoverable if the shot in the Jpeg format."
The last line is perhaps the most important. The ability to correct an image when you've over exposed or got the white balance incorrect at the point of taking the image. With a Jpeg file every change you make to the photo in post processing will slightly destroy the image. With a Raw file image you cannot actually change the physical image. When you make a change in say Photoshop or Lightroom in reality the software is simply make a text file with the changes and then outputs them to a new copy of the file in jpeg for example if you choose to export and create a final copy. It means the Raw file is like a digital negative - a locked down and unchangeable file. This means you can make changes to things like white balance, contrast and exposure without affecting the core image.
After dropping the original image into Lightroom I spent a while playing with the contrast and exposure settings and with some careful changing I was able to bring the exposure of the street back down and play with the darkness of the alley to reveal some of the details out of the gloom. I made a few changes to the colour filters and removed a small amount of un-required detail from the edge of the shot.
Canon600d with a Sigma 18-250mm f/3.5-6.3 DC OS HSM / iso200 / F4