I was asked about the HDR photo taken on Lough Salt at our first outing. I promised a brief tutorial on how that was created. Here goes.
A few basics about creating a High Dynamic Range image.
There are two main ways to create the source images needed for HDR. You can either use AEB, auto exposure bracketing, on your camera to take 3 images, or you can use RAW to take 1 image and then use a RAW editor to produce 3 shots back at your computer. There is various software on the market which handle both methods. I use a package called Photomatix because it is considered to be the best and because it can handle both methods.
For this image I took three photos. I used a monopod as I hate using a tripod when I’m out and about but the basics behind a HDR image is that you will be combining multiple images of varying exposures. The final image will be affected by how steady you hold the camera so I would recommend that if you have a tripod, use it !
So first thing is to shoot the 3 images.
For this I use auto exposure bracketing on my Canon. Most DSLR have this option in the menu. It will look something like this;
You should also change your camera from single shot to continuous shooting. The camera will automatically change the exposure for each of the 3 shots, in this case as follows;
The first image
The second image
The third image
You now need to open Photonatix on your computer. Photomatix can process multiple images in batch, it will look at 3 images at a time. You do need to be careful that you have sets of 3 in the relevant folder. For this I am processing just one HDR from 3 images so I choose Generate HDR.
Leave default values until you see the effect. You can always regenerate the HDR when you see how the various settings affect the final image. The option to Align Images will improve the image if you shot it hand held.
The generated HDR image looks disappointing…
This is because it can’t be represented properly on screen without further processing. An unprocessed HDR image is in a way similar to a film negative, or the RAW file of a digital camera. It needs further processing for display or printing. In Photomatix, this processing is called Tone Mapping.
Tone mapping reveals the details in highlights and shadows contained in the original HDR image. It converts the HDR image in 32 bits/channel mode into an image in 16 or 8 bits/channel mode that can be saved as TIFF or JPEG. To tone map your HDR image, click on the Tone Mapping button on the HDR viewer window.
The final image. You should now save this image.