Q Factor - what is the correct setting?

[EricLawrie]

I have always used a Q factor of 1 for all my slide scans. I now note that the rollover message in the latest version of Silverfast is "Normal Q factor 1.5". On page 38 of "Silverfast - The Official Guide" it states "Leave this set to the default factor of 1.0" and then on page 55 "I tend to side with the Silverfast suggestion of Q at approximately 1.4".

I am now very confused. Please could someone at Lasersoft help clarify the appropriate Q factor for ordinary slide/transparency scans.

Kind regards, Eric Lawrie

[LSI_Noack]

Dear Eric

the Q-factor of 1.0 is IMHO sufficient for normal flatbad scans.
The value of 1.5 reflects pre-press standards.
You can use the default setting for slide scans comfortably

[Gregory C]

the Q Factor only applies if you have no distinct output resolution in mind. if you are scanning for the sake of archiving, or for on-screen viewing, or even for home printing, the Q Factor can be ignored.

the Q Factor is used (in general) by people who need to scan images for output at a printer agency using offset printers. normally, they will have been told the ideal output screen resolution by the printers. the user will enter this into the Screen field and then specify a Q Factor. SilverFast then calculates the correct resolution based on those values.

historically, a Q Factor of the square root of 2 has been considered to be the most economical and effective Q Factor. the president of Lasersoft can tell you much more about this.

in the meantime, if you are scanning to print from an inkjet printer, ignore the Q Factor and specify a resolution of about 360 dpi for very acceptable output.

regards
Gregory