Chromatic aberration compensation function (CAC)

The chromatic aberration compensation function minimizes color smearing in peripheral images. This function automatically compensates for registration error that is caused mainly due to slight chromatic aberration, which is hard to completely compensate with the lens itself, using the camera recorder unit.

When the lens compatible with the chromatic aberration compensation function is mounted, if the camera has the chromatic aberration compensation data of the lens, then the chromatic aberration compensation function is activated automatically.

What is lens chromatic aberration?

other_cac_status

“Chromatic aberration” here refers to zoom factor chromatic aberration. Zoom factor chromatic aberration occurs since the diffraction ratio of a lens differs according to red (R)/green (G)/blue (B). Chromatic aberration on the lens itself is compensated for, but still remains in the periphery, in particular. Also, this chromatic aberration occurs on zoom lens due to a complex relationship between zoom ratio, iris and focal distance. In image terms, this is registration error.

Chromatic aberration compensation function

To compensate chromatic aberration, store the chromatic aberration characteristics of the lens regarding zoom ratio, iris and focal distance to the camera recorder beforehand. Connect a lens that matches those chromatic aberration characteristics, and perform compensation matched to the zoom ratio, iris and focal distance of that lens.

The following type of chromatic aberration compensation function data for lenses is stored in the camera before it is shipped.

Display on the camera

Corresponding lens parts number

XT17X4.5BRM-K14

XT17x4.5BRM-K14

Operation of chromatic aberration compensation function

Operate by the following procedure when lens data is already stored on the camera.

Mount the lens on the camera, and connect the lens connector to the camera.

Set to [ON] using main menu → [MAINTENANCE] → [CAC ADJ.] → [CAC CONTROL].

If the lens model number stored on the camera matches the model number of the connected lens, the chromatic aberration data stored on the camera will automatically be read.

Checking the operating status of the chromatic aberration compensation function

Push the <DISP/MODE CHK> switch towards the <CHK> side five times.

The mode check [CAC INFO] screen is displayed.

If [CAC CONT] is displayed as [ON] in the [CAC INFO] screen, the chromatic aberration compensation function is in operation. If other than [ON] is displayed, the chromatic aberration compensation function is not in operation.

Also, if [CAC ACTIVE] is displayed in the SmartUI [CAM01:STATUS] screen, the chromatic aberration compensation function is in operation. If other than [CAC ACTIVE] is displayed, the chromatic aberration compensation function is not in operation.

Loading the chromatic aberration compensation file from the SD memory card

co_osd_cac_load

Insert the SD memory card written with the chromatic aberration compensation data you downloaded from our website into the camera.

For details on downloading, refer to the following website.

https://pro-av.panasonic.net/

Select [LOAD] in the main menu → [CARD FUNCTIONS] → [CAC FILE]. (Fig. 1)

The list of CAC files on the SD memory card is displayed.

Select the file number to load, and press the jog dial button (or <SET> button). (Fig. 2)

A confirmation screen is displayed.

Select the file number to save, and press the jog dial button (or <SET> button).

A confirmation screen is displayed.

Select [YES], and press the jog dial button (or <SET> button).

The CAC files are loaded to camera memory.

To store multiple chromatic aberration compensation data files in the camera repeat steps 2 to 5.

To end menu operations, press the <MENU> button.

The setting menu disappears, and the camera status display is returned to.

Deleting the chromatic aberration compensation file from the camera

co_osd_cac_delete

Set to [OFF] using main menu → [MAINTENANCE] → [CAC ADJ.] → [CAC CONTROL].

In [LIST/DELETE], select the lens part no. you want to delete and press the jog dial button (or the <SET> button). (Fig. 1)

A confirmation screen is displayed.

Select [YES], and press the jog dial button (or <SET> button).

The file is deleted.

When the chromatic aberration compensation data is not functioning properly

When the chromatic aberration compensation function is not functioning properly, or when the chromatic aberration compensation data could not be loaded normally, the viewfinder displays an error message.

Error message

Meaning

Remedy

[CAC FILE DATA NOT FOUND]

There is no chromatic aberration compensation data matching the connected lens when the chromatic aberration compensation function is [ON].

This is displayed when the camera is turned on or the lens cable is connected.

Load chromatic aberration compensation data matching the connected lens to the camera.

[CAC LENS DATA INVALID]

The response data from the lens is not supported, or the response contains information other than that defined in the chromatic aberration compensation data.

The lens is not a lens compatible with the chromatic aberration compensation function.

The chromatic aberration compensation will not function, but will not cause any problems in use.

[LENS INIT. NOT COMPLETED]

Position detection (focus zoom) of the lens is encoder type, and initialization is not completed.

Turn the focus/zoom ring to pass through the center of the operating range.