TIF Scan Prep: Is It Necessary (or Beneficial) for TIF Files that are Already Gamma 2.2?

Obviously, there are no rules dictating what one has to do with regard to prepping a film scan prior to color conversion with NLP, but a question arises: If a scan of a color negative was already generated with gamma 2.2 by the scanning software, would the TIF Scan Prep utility make any observable difference to the color conversion done by Negative Lab Pro?

My understanding is that the TIF Scan Prep utility essentially does the following:

  1. Takes the original TIF file and temporarily converts it to gamma 1.0 (regardless of the file’s original gamma);

  2. Applies color multipliers to the gamma 1.0 color space; and finally

  3. Converts the file to gamma 2.2 (this is the form of the TIF file that is then worked on by NLP).

The intention of the utility seems to be to expand the tonality of the original file before it gets worked on by NLP. In practice, this expansion of tonality should be observable in an expansion of the histogram of the image after the TIF Scan Prep utility has been used. But, if the original scan was already generated with gamma 2.2 by the scanning software, should the “deconversion” to gamma 1.0 followed by “reconversion” back to gamma 2.2 have any practical effect?

Thanks in advance for your feedback.

1 Like

Hi @sbadham :wave:

Yes, this what the Tiff Scan Prep utility currently does.

Yes, it will make a difference because of step #2. The color multipliers are more accurately applied when in gamma 1.0 - because in gamma 2.2 the gamma curve will impact each color channel slightly differently because each color channel will be in a slightly different place along the curve. Will it make a big difference? Not necessarily. But it should be slightly more accurate.

With all that said, though, the biggest difference of using the Tiff Prep Utility will definitely be when working with a gamma 1.0 file because the expansion of tonality on the original Tiff helps with accuracy once you begin converting and editing in NLP.

I continue to experiment with alternatives to the Tiff Prep Utility because of the time & storage the extra step consumes.

1 Like

Understood. Thanks for clarifying, Nate!