How and Why to Lock Exposure when Scanning Film
If you’re scanning several frames from the same roll of film, the following procedure will optimally set the CCD exposure and film base color (i.e. mask color):
Set Input | Options to ‘Professional’.
- Set Input | Media
- Insert film with a transparent area
- If Input | Lock exposure is visible, clear Input | Lock exposure
- Press the Preview button
- Adjust cropping if necessary
- If Input | Lock exposure is visible, set Input | Lock exposure
- Press the Preview button again
- If Input | Lock film base color is visible, set Input | Lock film base color
For step #2 above, use a film frame that has an area that would print as pure black for negative, or pure white for slides.
Regardless of the lighting conditions, shutter speed and aperture of each frame, you should use these fixed values for exposure and film base color for scanning all frames on the roll of film. Once you have the exposure and film base color fixed, you can scan the whole roll of film using these values.
- If you’re using the same lighting for all the frames on the roll (or a subset of the frames), you can lock the color balance by scanning the brightest frame in the series and then setting the Input | Lock image color option. This will lock the black and white points for the scene, and will produce consistent colors for all the frames in the series. This is also useful if you’re scanning panoramic scenes that have all been taken with the same lighting, shutter speed, and aperture, or if you’re scanning a series of studio shots taken with the same lighting, shutter speed, and aperture.
- To optimize workflow, scan to raw files and experiment later with color correction. Make sure you first set Input | Lock exposure before scanning a roll of film.
- If you’re saving raw scan files, you can turn off Output | TIFF file and Output | JPEG file. You may also want to capture the entire preview area instead of the auto-cropped area by clearing Crop | Auto offset and Crop | Auto rotate and setting Crop | Crop size to “Maximum”.
- For quicker batch scanning, set Input | Lock exposure and clear Crop | Auto offset and Crop | Auto rotate. This will stop the Scan button from creating a preview.