Embed Size (px)
Transcript of HDR Photography
TOPIC: HDR PHOTOGRAPHYAMITY UNIVERSITY, UTTAR PRADESH
BACHELORS IN JOURNALISM AND MASS
A Amit Kumar Dash Presentation
What is HDR Photography?
High dynamic range imaging (HDRI or HDR) is a set of
methods used in imaging and photography to allow a greater
dynamic range between the lightest and darkest areas of an
image than current standard digital imaging methods or
HDR images can represent more accurately the range of
intensity levels found in real scenes, from direct sunlight to
faint starlight, and is often captured by way of a plurality of
differently exposed pictures of the same subject matter.
In simpler terms, HDR is a range of methods to provide higher
dynamic range from the imaging process. Non-HDR cameras take
pictures at one exposure level with a limited contrast range. This
results in the loss of detail in bright or dark areas of a picture,
depending on whether the camera had a low or high exposure
HDR compensates for this loss of detail by taking multiple
pictures at different exposure levels and intelligently stitching
them together to produce a picture that is representative in
both dark and bright areas.
Non-HDR cameras take photographs with a limited exposure range,
resulting in the loss of detail in bright or dark areas. HDR compensates for
this loss of detail by capturing multiple photographs at different exposure
levels and combining them to produce a photograph representative of a
broader tonal range. HDR images are also acquired using special image
The two primary types of HDR images are:
1. Computer Renderings
2. Resulting from Merging Multiple Low-Dynamic-Range
There are two broad rendering intents of HDR processing
Photorealistic and Artistic
• Photorealistic attempts to reveal what the scene looked like to the makers eye.
• Artistic meant to be more like “Art” and not necessarily represent the actual
Some example scenes that are generally good for HDR:
• Bright sunny day
• Night scenes
• Indoor scenes where bright sun is visible through windows
• Outdoor scenes with highly reflective elements such as water falls.
• Initial capture - bracketed range or single image (some HDR processing
on a single exposure is possible)
• Minimal image prep in RAW development or pre-HDR processing of
• Save As TIFF files
• HDR software tools to create a combined image of high dynamic range
exposures (in 32 bit and then converted by software to16 bit)
• Final image processing in Photo Shop
• Save completed image ready for output
Major HDR Processing Software Suppliers:
1. HDR Soft - Photomatix Pro
2. Nik Software - HDR Efex Pro
3. Adobe - Photo Shop HDR Merge
1. HDR PhotoEngine
2. Essential HDR
3. FDRTools Basic
In Photography, dynamic range is measured in EV differences (known as stops)
between the brightest and darkest parts of the image that show detail.
An increase of one EV, or one stop, represents a doubling of the amount of light.
NEGATIVE FILM 13
HUMAN EYE 10-14
Dynamic ranges of common devices
The idea of using several exposures to fix a too-extreme range
of luminance was pioneered as early as the 1850s by Gustave Le Gray to
render seascapes showing both the sky and the sea.
Such rendering was impossible at the time using standard methods, the
luminosity range being too extreme. Le Gray used one negative for the sky,
and another one with a longer exposure for the sea, and combined the two
into one picture in positive.
Mid- twentieth century
Manual tone mapping was accomplished by dodging and burning – selectively increasing
or decreasing the exposure of regions of the photograph to yield better tonality
reproduction. This is effective because the dynamic range of the negative is significantly
higher than would be available on the finished positive paper print when that is exposed via
the negative in a uniform manner.
An excellent example is the photograph Schweitzer at the Lamp by W. Eugene Smith, from
his 1954 photo essay A Man of Mercy on Dr. Albert Schweitzer and his humanitarian work
in French Equatorial Africa.
The image took 5 days to reproduce the tonal range of the scene, which ranges from a
bright lamp (relative to the scene) to a dark shadow.