My Lumix LX7 has an ‘high-dynamic range’ feature. Otherwise known by its initials ‘HDR’, high-dynamic range is a technique for digital imaging that allows greater detail in highlights and shadows by combining several images of the same subject that were exposed at different values.
The LX7 includes the HDR setting as one of the options in ‘scene mode’ (SCN on the selection dial). This rapidly exposes a sequence of images and combines them in-camera to produce a single HDR JPG. Obviously you need to hold still when you make the photo.
Also it helps to photograph a static scene or the result my get a bit weird.
In this instance, I photographed some flowers on the platform of NI Railway’s station at Whitehead, Co. Antrim (Northern Ireland).
There are other ways of accomplishing a similar result.
So I decided to compare the HDR with some manipulated versions of a camera RAW file that I exposed of the same scene. With the RAW images, I’d adjusted the file with Lightroom post processing software, selectively altering contrast, gamma, and colour saturation and colour temperature to make for a more pleasing photograph.
Specifically I applied a digital graduated neutral density filter, while making global changes to highlights and saturation.
The output of the RAW is also as a JPG, which I scaled for presentation here.
I made two versions of the RAW interpretation.
In both sets of images I’ve intentionally focused on the flowers and not the NIR train.
Among the built-in features of the Panasonic LX7 is a HDR—High Dynamic Range—setting in ‘Scene Mode’.
The theory behind HDR is the ability to produce a digitally exposed photograph with better highlight and shadow detail through post-processing blending of two or more images of the same scene exposed at different light settings. (In other words, a multiple exposure).
A common way to accomplish this is to place the camera on a tripod and make three images of identical composition with one image over-exposed (too light), one normally exposed, and one underexposed (too dark). Then combine all three images as multiple exposure.
When done effectively this can be used to overcome the limited dynamic range inherent to digital sensors. It can also be used creatively through extreme exposure variations to produce some outlandish images with nightmare skies and penetrating shadows.
The LX7s feature makes exposing a basic HDR style image exceptionally easy as the camera automatically takes three photos in rapid sequence and processes them immediately in-camera to produces a blended Jpg available for viewing.
I found this most effective in high contrast scenes, such as sunsets, that might be difficult to capture because of the camera’s limited exposure range. In other situations, it seems to flatten the contrast and doesn’t necessarily make for a more pleasing photograph.
Another point, if the scene isn’t static, ‘ghosting’ will occur of moving elements. My sense is that camera’s software must have a comparative feature that attempts to minimize the effect of ghosting, but the results can appear unnatural if not outright bizarre. Especially, when the subject, say a passing locomotive, become transparent!
Below are a few of my experiments. With most I’ve first included a comparison image (an ordinary non-HDR photo) exposed in the normal way.
This is a work in progress, and I’ll follow up in more detail in a later post.