Vignetted Lenses | Boris FX

< Previous | Contents | Manuals Home | Boris FX | Next >

‌Vignetted Lenses

You may be presented with a vignetted image, something like this anamorphic image:

It is important for SynthEyes to know which is the good portion of the image, for both workflows:

 Workflow #1: the output rectangle must be inset, so there are no black vignetted pixels in the output rectangle.

 Workflow #2: the output rectangle doesn't need to be unnecessarily large in order to encompass pixels that are black anyway.

To do this, add a rotomask that encloses exactly the valid portion of the image, and none of the vignetted portion. Recommended: delete the underlying default rectangular spline.

NOTE : Be alert for mispositioned dots or lines at the edge of a vignetted image.

Some sample processed results are shown below. In each case, the visible image shows what is being output; compare that with the (modified) positions of the trackers to see what portion of the now-undistorted image is being used.

Workflow #1: No

Spline (invalid pixels in frame)

Workflow #1: With Spline (all pixels valid)

Workflow #2: No

Spline (wasted space)

Workflow #2: With Spline (tighter packing)

Note that the spline coordinates are not updated in this process, they still reflect the original positioning, so you should ignore them after the calibration process has run.

TIP : For workflow #1 and vignetted lenses, use the Override Aspect control to pull a final image with a desired aspect ratio from inside the vignetted image. SynthEyes will take that final aspect ratio into account. For example, pull a 2.35 image from inside a 16:9 image with a 2:1 anamorphic lens.

Depending on which workflow you are using, #1 or #2, you can shift the spline boundary in or out a little over the "gray zone" right at the vignetting boundary.

< Previous | Contents | Manuals Home | Boris FX | Next >