Creating perfect photos from your slide and negative scans with ColorPerfect: SilverFast SE 6.x, SilverFast Ai 6.x

 

Another scanner software that enables you to create linear slide and negative scans is Lasersoft Imaging's SilverFast SE or Ai. To create a 16 bit linear scan start by selecting the General tab. There you need to set the "Scan Mode" to "Normal (File)" and to select "Positive" from the drop down list next to "Pos./Neg.".

As a second step navigate to the Frame tab. Here you need to define "48 Bit HDR Color" to be the "Scan Type". All image editing choices will be disabled after doing so. SilverFast now operates in its RAW mode. The resulting Tiff files - which are sometimes referred to as SilferFast HDR files - contain linear intensity values as are being read in by the scanner and as is required for negative conversions with ColorPerfect's ColorNeg mode or the previous ColorNeg plug-in.

The Gamma setting in SilverFast usually does not influence HDR scans at all. The files recorded in HDR mode normally contain unchanged sensor data and thus are of linear Gamma. There is a setting among SilverFast's options however that will let HDR scans get gamma encoded just like ordinary scans. To avoid this you'll need to make sure that the checkbox "for HDR output" next to the "Gamma-Gradation" field on the options' General tab is left unchecked.

Some options that can exclusively be executed during scanning itself will remain active when operating in HDR mode. One such option is the automated removal of dust and scratches via Digital ICE. If you want to use this on your negative or slide scans you can do so. When scanning color negatives it is also advisable to consider the use of multi sampling. That is if this is supported by the particular scanner hardware you possess.

For some scanners further options on the special tab can be of interest. If you are using an older scanner model which supports the adjustment of lamp brightness or respectively exposure time for the individual color channels which is often referred to as analog gain you can utilize that to reduce the orange mask of a color negative during scanning or even to eliminate it altogether. An example of scanners allowing you to do this is the Nikon Coolscan series. In a typical linear scan of a color negative the blue channel is more than two exposure values below the red channel and the green channel often is more than one EV below it. For modern scanners with 16 bit/channel precision this often is irrelevant for inverting the negative as there is still enough detail to work with. For older scanner models with 14 bit precision or even only 12 bit precision equalizing the three color channels' lightness before analog/digital conversion can improve the quality of the inversion. If we consider that the blue channel typically is the least detailed portion of the scan we can observe that it is possible to bring its quality up to the level of that of a scan with 2 bit/channel more precision. In SilverFast you can use the option lamp brightness which is on the option's special tab to bring up a dialogue to manipulate these settings. It is noteworthy however that often the lamp brightness can't be increased any further. In case of the Nikon Coolscan scanners exposure time will be lengthened instead. It is conceivable that for other scanner models an analog amplification of an electric signal might be used which would most likely not lead to the desired improvement. Using this feature with any scanner will require a series of tests.