Exposure Bracketing vs. HDR

December 06, 2014 • Leave a Comment

Is it Bracketing or HDR?
Exposure Bracketing Simply explained, exposure bracketing is a process in which multiple photos (usually between three and seven) of the same subject are taken in sequence using different exposures. Exposures are changed using either different shutter speeds (Tv) and the same aperture (Av, or f-stop), or different aperture settings and the same shutter speed. When using three exposures, one photo is underexposed, one is properly exposed, and one is overexposed. The purpose is to increase the dynamic range of the photograph from the shadow to highlight areas. Exposures are adjusted by using shutter speed (Tv – Time Value) or by using lens opening (Av – Aperture Value). Using a slow shutter speed or using a low f/stop (wide opening) increases the amount light reaching the sensor. Increasing the shutter speed or using a high f/stop (small lens opening) decreases the amount of light reaching the sensor. Remember, a lower f-stop number increases the lens opening when the shutter is released. Increasing light increases exposure; decreasing light decreases exposure.
In the examples below the image is properly exposed and looks good. However, notice that the shadow areas are dark and lack shadow detail, and the bright, or highlight areas lack highlight detail. Photographic detail is only preserved in the properly exposed area of the subject.
IMG_0935Normal exposure	IMG_0879

In the underexposed photos below, the highlight areas become less bright and appear properly exposed and with good detail, but the shadow areas become very dark and lack detail.
IMG_0934	IMG_0878

In the overexposed photos the highlight areas are “blown out,” and the shadow areas appear properly exposed and maintain shadow detail.
IMG_0936Overexposed	IMG_0880

By combing exposures, the resulting photo benefits by the details captured in each of the exposures and presents as a properly exposed image with good shadow to highlight detail, while at the same time showing good color that is not over-saturated.
Natural_Living Room	IMG_0878_79_80_fused

Exposure bracketing can be especially useful in interior architectural photography in which lighting tends to be very uneven from one side of a room to another. It enables the photographer to capture the room with with even lighting and capture details that would otherwise not be visible. Bracketing can also be successfully employed for exterior architectural photography, especially on very bright days. It enables the photographer capture the bright, blue sky (highlight detail) as well as details in the portion of the structure that is shadowed. However, many photographer have a tendency to apply too much of the effect. Bracketing should not be confused with HDR…
HDR (High Dynamic Range) photography HDR photography is a form of bracketing and can usually be identified by highly detailed photos with very saturated colors. Depending on how it is applied. some HDR tends to be very surreal looking, and in many cases HDR results tend to be “over-baked” and fake looking. HDR photography, or as some call it, HDR Blending,” is very useful for artistic photography in which the photographer’s desire is to accentuate vibrant colors and extreme detail. Good examples of HDR can be seen in landscape photography in which the sky and cloud formations become very well defined, or to accentuate the colors of the rising or setting sun. Twilight and dusks scenes of buildings and cityscapes also provide great examples of the proper use of HDR, as does the photography of abandoned structures and rusted objects (buildings, cars, trucks, boats, etc.). Properly used, HDR is a very effective form of photography, but when overdone, HDR can leave much to be desired, especially in interior architectural photography. Many photographers who use the HDR process for blending exposures, especially in real estate photography, tend to apply too much of the effect, resulting in photos that look unnatural, surreal, and artificial. This is not only true of interior photography, but is also of exterior photography.
IMG_0934_5_6_fused-b	soft

The photos below are a good examples of the artistic use of HDR. In the sequence below you will see three exposures of the same image: underexposed, properly exposed, and overexposed. Following the separate exposures are several applications of HDR.
Underexposed The images below are far too dark, revealing no detail.
Abandoned_5-2	IMG_8533
Properly exposed These image have a nice even exposure, but lack detail and contrast. Colors are not vibrant.
Abandoned_5	IMG_8532
Overexposed The images are so overexposed that there is no visible detail.
Abandoned_5-3	IMG_8534
HDR - Fused In the examples below, colors are saturated and detail is greatly enhanced. Notice on the house how the blue door and window frames that in the normal exposure appear washed out. You can also see the texture in the wood. Also notice how green the foliage has become. Also notice the wood grain in the car (what is left), the leather on the steering wheel, and the moss growing on the dash.
Abandoned_5_-2_-3_fused	IMG_8532_3_4_fused
HDR - Tonemapped These are more extreme examples of HDR.
Abandoned_5_-2_-3_tonemapped	IMG_8532_3_4_tonemapped