HDR Photography: The Power of High Dynamic Range Photography

advertisement

We’ve all been there. That beautiful sunset will not photograph well with your camera--if the range from the dark to bright is greater than the range of your camera you may have this issue. In days gone by the only solution was to analyze the scene, determining the key tones.

Sometimes you had to minimize the highlights and sometimes you had to overemphasize the highlights. Oftentimes, this led to walking away from the splendor with no picture because it was not as it could be seen by the naked eye. Now we live in a digital age and such scenes can be captured using HDR, but I must warn you there is a certain amount of disparity of opinion regarding the use of HDR.

Why HDR?

There is a group of people who liken the use of HDR to cheating on a test. These “purists” think photography should be a reflection of reality only. Others in the school of elitists assert that multi-exposure shooting or bracketing requires little to no skill. In my opinion using HDR does not mean cutting corners. However, neither does it give you the upper hand in photo editing. It is only smart to use whatever is at your disposal to produce a more appealing and satisfying product. Your photography will still be as skilled as you are.

The HDR Photography Process

High dynamic range photography involves using different shots to build an image that features a high range of colors and then blending these pictures digitally with a computer. Specialized software is required for this process. The software optimizes exposures you took for the same image to create the desired depiction of the image and ensures removal of the undesired shadowed/highlighted areas. By using HDR, you can reveal the details both in the underexposed and in the overexposed areas.

Baby HDR

The HDR process is still new. The horizon for the use and expansion of HDR and beyond are unknown. Perhaps in the near future cameras will utilize HDR in order to handle scenes featuring HDR. I believe the process for post-processing will become more sophisticated as well. Already some tools we have today are able to create incredible HDR photos.

Seeing the whole picture

Human sight is not capable of “seeing the whole picture.” Yet the wonderful human brain puts the pieces together and fills in the gaps. As our eyes move quickly over a scene, taking note of it in increments, and our brain assembles these optical pieces into a single coherent unit. Our mind can also finish a picture for us, from past experience.

As our eyes move, they adjust to the amount of light, tone, and texture of the scene. HDR is similar, except that you end up capturing the entire screen with your every shot. However, limited areas are exposed by each shot. When viewed in this way HDR seems to be more complete than a single exposure allows and so it is true to the image.

How To Capture The Screen

If possible, use a tripod when shooting. While the software can fix the issues of movement while shooting manually, your image will be much improved if its data is of the highest quality possible (i.e., by using a tripod!). The scene dictates the number of required exposures. 5 exposures are most often needed and most DSLR cameras have the option of viewing a histogram and have an indicator for clipping which can be set on the screen. First, you should under-expose the scene so that the histogram is as far left as possible, showing you the shadows. Then go ahead and diminish shutter one full stop before you take the second shot. Please note, the aperture is to remain the same throughout the entire process. Continue the process in the same manner until you reach your 5-shots count.

HDR Ruts & Gullies: Banding, Flare, Ghosting, and Haloing

The most common drawbacks for shooting for HDR are banding, flare, ghosting, and haloing. Banding and haloing happen there is a contrasting difference between the light and the dark in a scene. Such is the case of an open door with the sunshine outside. Movement causes ghosting is caused and light from a bright light source causes flare. This is often seen in photos where people are not still or with lights in the background.

Using Photomatix

Photomatix is one of the oldest and most widely recognized software available for HDR image production. Tone mapping will be discussed in a future article.

  1. First select the “Generate HDR Image” shortcut. You will now have to select the desired sequence of photos.
  1. Next select the “Generate HDR” button. The Photomatix program merges the picures and generates an HDR image. While the resulting temporary image does not show the full range, this is addressed with the “Tone Mapping” button. This produces an image where the full details of both shadows and highlights are visible.
Tags: