Sony α 7SII Instruction Manual

Introduction to Picture Profile

What is Picture Profile? [1]
Gamma and Knee [2]
What is S-Log? [3]
Color Space [4]
Detail [5]

Picture Profile setting parameters

Setting basic contrast/coloring (Gamma/Color Mode) [6]
Adjusting contrast (Black Level/Black Gamma/Knee) [7]
Adjusting coloring (Saturation/Color Phase/Color Depth) [8]
Emphasizing image edges (Detail) [9]

[1] Introduction to Picture Profile

What is Picture Profile?

Picture Profile is a menu for adjusting and changing parameters that determine an image’s
characteristics. There are many parameters that can be adjusted, but they can be grouped
into 4 types — parameters for selecting basic contrast and color tone, parameters for
adjusting gradation (darkness-brightness tone), parameters for adjusting coloring, and
parameters for emphasizing image edges.

Select MENU → (Camera Settings) → [Picture Profile] → the profile you want to

change, and you can directly enter the Picture Profile setting mode.
Supporting a wide range of adjustable settings, this camera’s Picture Profile menu allows you
to change a variety of settings, such as Gamma Curve, Color and Detail. Up to 7 sets of
setting combinations can be stored in the internal memory as PP1 through PP7.

Available functions may vary depending on your camera.

Using Picture Profile presets

This camera is equipped with several Picture Profile presets as a default setting. By using
these presets, you can match the image texture with other types of cameras equipped with
the [Picture Profile] function, or create an image texture that is similar to that of cinematic
film.

Difference from image processing using nonlinear video
editing software

Picture Profile adjusts colors and the vividness of the image during recording. You can make
similar adjustments by using nonlinear editing software after shooting. But there are the
following differences.
To fit massive amounts of image data in a limited memory capacity, this camera compresses
image data when recording. No matter how advanced a compression format is, any data
compression inevitably deteriorates image quality somewhat. Applying sharpness, gamma
curve correction and other video effects to recorded images by using nonlinear editing
software worsens the image condition further by processing already deteriorated images.
For example, if video compression leaves the image with poor contrast or block noise in
some areas, applying video effects often make the problems more noticeable.
Because Picture Profile processes video signals before compressing, it changes the gamma
curve and corrects colors before image quality is damaged by compression. This makes it
possible to carry out highly precise image adjustments while keeping the quality of the
subject intact. It should also be noted that recording images with proper contrast is crucial. If
image contrast in dark and bright areas is not recorded properly, this will result in
underexposed dark and overexposed white areas with no gradations. This means you
cannot change image contrast properly later on with nonlinear editing software no matter
how hard you try because there will be no gradations to work with.
If you intend to process your video with nonlinear editing software later, it is important that
you record your image in the right way.
Nonlinear editing software is a very powerful tool, but can’t fix everything. If you adjust
various settings to make sure your video is recorded in a way that matches your ideal as
much as possible, you will be able to create a video that will be closer to what you have in
mind with minimal processing via nonlinear editing software. It will also keep rendering time
short and make video editing work more efficient.

What to do with Picture Profile

If you are working on a project with ample time for editing or a short piece, record an image
that is as flat as possible to allow for many different kinds of post-production image
processing and color adjustments.
If you are working on a project with a tight deadline or a long piece, on the other hand, you
can dramatically reduce the amount of post-production image processing and enable highly
efficient production by recording the video as close to the vision of the finished image as

possible. Showing the image being recorded to the director and crew as close to the tone of

the ideal finished image as possible on a display monitor will greatly boost morale on the
scene, which has a major impact on the quality of the finished work. In order to avoid the
problems with nonlinear editing described in the previous section, and also to create pieces
with mobility that make the most of this camera’s unique characteristics, try to fully utilize
Picture Profile while recording images at the proper settings.

[2] Introduction to Picture Profile

Gamma and Knee

Gamma curve, knee point, and knee slope are elements that exert great influence over
image characteristics. By understanding these, you’ll be able to utilize Picture Profile
efficiently.

What is a gamma curve?

Gamma curves show the relationship between the input signal level and the output signal
level. The camera converts the brightness signal from the subject into an electrical signal
and sends the electrical signal to the display monitor, which converts that signal back to a
brightness signal and reproduces the subject as an image. The input signal level is the level
of the brightness signals from the subject and the original image, whereas the output signal
level is the level of the brightness signal output by the camera or display monitor.
In order to faithfully reproduce a subject in video images, the output signal level needs to be
largely proportional to the input signal level, as shown in the straight line below. But the
fluorescent material characteristics of a CRT (cathode-ray tube) cause the output signal level
from CRT monitors to curve as shown below. This represents the gamma curve of CRT
monitors. The camera’s video gamma curve plots the opposite curve. For this reason, the
properties of the camera and CRT monitor can be offset to faithfully reproduce and display
the original subject.
The inherent characteristics of an LCD (liquid crystal display) cause the output signal level
from LCD monitors to be largely proportional to the input signal level. However, because the
camera is designed for CRT monitors, LCD monitors and OLED (organic light-emitting
diode) monitors mimic the CRT’s gamma curve.

How the gamma curve’s shape influences images

Influence on dark areas and contrast

High-end cameras have a function to slightly change the shape of the gamma curve for dark
areas of the image, known as Black Gamma. Changing the gamma curve shape lets you
dramatically alter the atmosphere of the image by strengthening or weakening the shading,
or contrast, of the image.

What is knee correction?

Cameras are, in general, not good at clearly capturing a scene that contains extremely
different luminance levels, such as one object in bright sunlight and another in the shade. If
you set the right exposure for the object in the shade, the object under the sun will be
captured too brightly and appear as a plain white object without texture or gradation. Knee
correction is a function necessary to keep these kinds of images with a large disparity in
luminance levels within the standard range of video signal levels. Just as Black Gamma
influences contrast in dark image areas, knee correction deals with contrast in image areas
with high luminance levels.
CCD and CMOS sensors can handle an extremely bright input signal. To output it as a video
signal, however, we need to keep the signal within the standard range for video. For this
reason, the signal output level is kept lower than the signal input level in high-luminance
areas that generate input signals over a certain level. In the chart below, the line bends like
a knee at a certain point in the high-luminance range. This is called the knee point. The line
extending from the knee point is called the knee slope.
By changing the position of the knee point and the inclination of the knee slope, contrast in

the high-luminance range can be altered. The breadth of input signal levels that a system

can process is called the dynamic range.

Without knee correction

With knee correction

[3] Introduction to Picture Profile

What is S-Log?

The S-Log2 gamma curve is optimized to the dynamic range of the CMOS sensor.
In order to bring out the contrast in highlights as much as possible, the sensor output has
been extended to 1300% of the dynamic range. Although some color grading work is
required, the S-Log2 gamma curve is an effective way to preserve highlight gradations that
would otherwise be lost, thereby providing greater exposure latitude in recording.

Camera settings

ISO 2000 24p 1/48
F5.6+ND1/64

Grading settings
Exposure

Shadow: –10%
Mid: +5%
Highlight: –4%

Color

Mid: 165° +1%
Highlight: 352° –1%

Saturation

Global: +49%
Mid: +66%
Highlight: +84%