Out-of-focus field modification, Avoid flare and distortion, Red motion mount operation guide – RED MOTION MOUNT User Manual
Page 14

COPYRIGHT © 2014 RED.COM, INC
RED MOTION MOUNT OPERATION GUIDE
955-0013, REV-E | 14
OUT-OF-FOCUS FIELD MODIFICATION
Use of “ND Only” with a high ND value and wide aperture may cause undesired results, including distortion or
flaring in the out-of-focus field. In some instances, vignetting may also occur at the edge of the image. This is
typical when using lenses with smaller image circles. It is recommend that you do not exceed 4.00 stops of ND
when shooting with wide apertures.
NOTE: For instance, if the MOTION MOUNT is set to 8.00 stops of ND, and the lens is set to T1.8, instead of
the normal circular bokeh pattern, the out-of-focus area may have undesired or intense flare.
AVOID FLARE AND DISTORTION
Use the following tips to avoid or dramatically reduce flare and distortion.
Increase T-Stop to T4.0 or greater: Increase the T-Stop to T4.0 or greater to dramatically reduce bokeh
distortion.
Reduce ND setting: Reduce the ND setting to five (5) stops or less to produce a more symmetrical bokeh.
Install a traditional ND filter: Use a traditional ND filter if a shot requires a wide aperture (to limit depth-of-
field) and also requires eight (8) stops of ND. Adjust the MOTION MOUNT to four (4) stops of ND and install
an ND filter. This removes bokeh distortion and flare, and also enables the use of the Soft and Square
shutter types.
NOTE: Effects of flare and distortion will be negligible at apertures greater than T4.0. Flare and distortion may
vary based on the lens. RED recommends testing each lens in conjunction with the MOTION MOUNT before an
important shoot.
NOTE: Selecting an ND value over 4.00 stops in “ND Only” results in the ND value on the main screen overlay
turning yellow. The following message displays on the MOTION MOUNT menu: “High ND with wide apertures
may cause bokeh asymmetry”.
High ND Notification