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Exposure

Allows you to adjust the exposure of the input sequence using f-stops, printer lights, film densities, or Cineon values.

Inputs and Controls

Connection Type

Connection Name

Function

Input

unnamed

The image whose exposure you want to adjust.

mask

An optional image to use as a mask. By default, the effects are limited to the non-black areas of the mask.

At first, the mask input appears as triangle on the right side of the node, but when you drag it, it turns into an arrow labeled mask. If you cannot see the mask input, ensure that the mask control is disabled or set to none.

Control (UI)

Knob (Scripting)

Default Value

Function

Exposure Tab

channels

channels

rgb

The exposure change is only applied to these channels.

If you set this to something other than all or none, you can use the checkboxes on the right to select individual channels.

colorspace

colorspace

Linear

Sets the output colorspace:

Linear - performs a linear multiplication to calculate the exposure.

Cineon - data is assumed to be raw data from a Cineon file requiring addition or subtraction. The result, when passed through a Log2Lin node, approximately matches the Linear result.

Note:  You can match Linear exactly if you set gamma to 0.6 and enable ignore in the Log2Lin node Properties panel.

blackpoint

blackpoint

0

Sets the black point (typically the darkest pixel). Any pixels of this value are set to 0. In other words, this color is turned into pure black.

Typically, you would set this by sampling the darkest pixels in the Viewer. To find these in your image, you may want to temporarily increase the gain in the Viewer node controls until only the darkest pixels are visible. Adjusting the Viewer gain does not affect the colors you sample.

gang

gang

enabled

When enabled, the color sliders are ganged together - adjustments to one affect all three.

red

red

0

Adjusts the exposure in the red channel.

green

green

0

Adjusts the exposure in the green channel.

blue

blue

0

Adjusts the exposure in the blue channel.

mask

N/A

disabled

Enables the associated mask channel to the right. Disabling this checkbox is the same as setting the channel to none.

maskChannelInput

none

The channel to use as a mask. By default, the effects are limited to the non-black areas of this channel.

inject

inject

disabled

Copies the mask input to the predefined mask.a channel. Injecting the mask allows you to use the same mask further downstream.

invert

invert_mask

disabled

Inverts the use of the mask channel so that the effects are limited to the non-white areas of the mask.

fringe

fringe

disabled

Blurs the edges of the mask.

(un)premult by

N/A

disabled

Enables the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.

unpremult

none

The image is divided by this channel before being processed, and multiplied again afterwards.

If you are using premultiplied input images, you may want to check (un)premult by and select rgba.alpha here. This will simulate applying the expressions before the premultiplication was done. It is the same as adding an Unpremult node before this node and a Premult node after, but allows you to work faster if you’re only using one color correct node.

If you are using unpremultiplied input images, you should leave this set to none.

invert

invert_unpremult

disabled

Inverts the use of the (un)premultiply channel.

mix

mix

1

Dissolves between the original image at 0 and the full effect at 1.