In my recent blog post ‘HDR Photography Using Mobile Phone Camera‘, I had mentioned an important point which stated that we should avoid including moving subjects in our scene. But why exactly should we not include the moving subjects while clicking photos on the HDR mode?
Also read: GETTING STARTED WITH HDR PHOTOGRAPHY
Basically, what happens inside the mobile phone camera when you click a photo in HDR mode is that the camera takes three photos of different exposures. Yes, three photos are clicked when you shoot using HDR mode, one photo is of normal exposure, the second photo is a bit overexposed and the third photo is a bit underexposed. These three photos are then merged into one HDR image.
As your camera is clicking three consecutive photos, there is a gap of some fraction of a second between each photo clicked. If you frame your scene such that a moving subject in included in it, then your final HDR image will witness ghosting effect.
As you can see on the top right corner of this image, there is a bird included in the frame and the photo is clicked on HDR more using a mobile phone camera. As a result, the bird is creating the ghosting effect and it appears that there are three birds, but actually there was only a single bird in the frame.
Such issues can be avoided by making sure that there are no moving subjects in the scene. In the situation such as the image above, you can always look around and time your photo in such a manner that you get perfect HDR image.
Though there are softwares and tools which allow you to eliminate the ghosting effect, but it is always better to get it right in the camera itself.