Densitometer values

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Densitometer values

Postby mikeah21 » Fri Mar 20, 2009 9:04 pm

I would like to be able to determine what the difference pixel values of a scan are so that the values read like a film densitometer. Is there a way to use either the 0-255 or 0-100 scale on the AI densitometer to calculate what the value might be on a film densitometer? Maybe this is a feature request too :D
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Re: Densitometer values

Postby LSI_Ketelhohn » Mon Mar 23, 2009 10:10 am

Dear customer,

The densitometer in SilverFast can only show the values of the digital image.
SilverFast only has the information the scanner collects to work on therefor the digital information is limited to the color-space/sensor-capabilities of the scanner.
Theoretically the RGB sensor of a scanner is capable of similar functions but it will never work exactly like a film densitometer.
When your click on the densitometer you can select different ways to display the values.
Can you please explain what exactly you expect?


kind regards
Arne Ketehohn
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Re: Densitometer values

Postby mikeah21 » Mon Mar 23, 2009 11:45 pm

Tag Arne,

I understand that in theory the software, scanner combination could only approximate what a film densitometer does but was wondering if there is a way to determine what an approximate film densitometer value would be, given a particular densitometer reading in Silverfast. Is there an equation or formula that could be used to translate the Silverfast value into an approximate film densitometer value?

LSI_Ketelhohn wrote:Dear customer,

The densitometer in SilverFast can only show the values of the digital image.
SilverFast only has the information the scanner collects to work on therefor the digital information is limited to the color-space/sensor-capabilities of the scanner.
Theoretically the RGB sensor of a scanner is capable of similar functions but it will never work exactly like a film densitometer.
When your click on the densitometer you can select different ways to display the values.
Can you please explain what exactly you expect?


kind regards
Arne Ketehohn
mikeah21
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Posts: 3
Joined: Fri Mar 20, 2009 8:49 pm

Re: Densitometer values

Postby LSI_Ketelhohn » Tue Mar 24, 2009 11:32 am

Dear mikeah21,

I talked to our color management expert about your request and he told me that he would not advice to use the scanner as a replacement for a film densitometer.
The scanner is not capable of the necessary functions.
For example the scanner lacks the necessary blue/UV filter which is used in normal film densitometer calculations.
So the normal densitometer formulas like Murray-Davies can not be used because they apply to different measuring setup.

kind regards
Arne Ketelhohn
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Re: Densitometer values

Postby mikeah21 » Tue Mar 24, 2009 2:43 pm

Arne,

Danke! for researching this request, and the information.

LSI_Ketelhohn wrote:Dear mikeah21,

I talked to our color management expert about your request and he told me that he would not advice to use the scanner as a replacement for a film densitometer.
The scanner is not capable of the necessary functions.
For example the scanner lacks the necessary blue/UV filter which is used in normal film densitometer calculations.
So the normal densitometer formulas like Murray-Davies can not be used because they apply to different measuring setup.

kind regards
Arne Ketelhohn
mikeah21
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Posts: 3
Joined: Fri Mar 20, 2009 8:49 pm

Re: Densitometer values

Postby LSI_Ketelhohn » Wed Mar 25, 2009 5:08 pm

your welcome ;-)
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