PhotoPerfect Manual

Lens Correction



With this function you can generate camera specific profiles which can then be used for pincushion correction.

Print reference sheet
Prints a test page which is used to register the lens specific errors by photographing it. The photography is easier with a large page size, e.g. A3. Photograph the page, starting with the smallest focal length and increasing stepwise to the largest focal length. The shots should be full page with as little angular deviation as possible. The steps should be closer together for the smaller focal lengths rather than equally spaced.

The function produces a 3:4 image format by default. Invoking it while keeping the [Ctrl] key pressed causes a 2:3 formatted image to be printed instead.

Acquire reference points
After you have photographed and stored images of the reference sheet with varying focal lengths, the eight reference points per image must be exactly marked. To this end, load and zoom each image in turn and right click each point exactly in the middle. The coordinates are automatically recorded in the reference point dialog. When the dialog is closed with OK the coordinates are saved.

Calculate lens correction
For this, all the reference sheet photographs for which reference points are saved must be selected in the thumbnail view. The correction data for the lens is determined and stored in a suitably named file with the extension *.ff. This file contains one focal length  and a corresponding correction factor per line. When you have successfully conducted this procedure, you can send it in to me with details of the camera type so that I can make it available to other users.