I have scanned several m/f monochrome negatives. Each one has been scanned twice, first as a 2000 dpi jpg and second as a 4000 dpi tiff. No other material changes have been made to the scanner settings.
Much to my surprise the jpgs are in every case much sharper than the corresponding tiff scan. I am using an Epson 4990 and SilverFast.
Does anyone know why this should be? I had expected the tiffs to be much better.
Any suggestions on how I can overcome this and get tiffs as good as the jpgs?
Sharpness - Tiff vs JPG
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Re: sharpness
Perhaps your TIFFs actually are better since losing information, read losing shades of gray in your case due to compression, may result in pictures looking sharper.
The extreme case would be a pure B&W scan which would certainly look very sharp.
Else what I can think of is that your negatives simply became bent due to the warmth of the scanner's lamp if you first scanned them all as JPEGs and then as TIFFs.
Last but not least keep in mind 4000 dpi is way beyond the physical resolution of your scanner and you may downscale your TIFFs and then compare again.
The extreme case would be a pure B&W scan which would certainly look very sharp.
Else what I can think of is that your negatives simply became bent due to the warmth of the scanner's lamp if you first scanned them all as JPEGs and then as TIFFs.
Last but not least keep in mind 4000 dpi is way beyond the physical resolution of your scanner and you may downscale your TIFFs and then compare again.
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LSI_Heidorn
- SilverFast Expert
- Posts: 435
- Joined: Fri Jan 18, 2002 1:00 am
- Location: Germany
Dear Jeff & jheinzl,
( partially repeating jheinzl's facts... )
normally the sharpness of a TIFF and a JPEG Image schould be very much the same ( if the JPEG Quality is set to a high value ).
Of course they are never the same as the JPEG introduces artifacts as it is a lossy format.
So if there is a strong difference and if the difference is not because of the compression artifacts, i'd say one of the following must be true:
-1- There was a different sharpness or focus setting between the two scans
-2- The film itself changed between the two scans. While this sounds strange it is a fact that e.g. a filmstrip gets warmer the more you scan from it ( high light intensity ) and starts bending, getting out of focus slightly more. ( This can be a problem for Multisample or MultiExposure scans, leading to the need of better fixture or using better film holders ).
-3- There is a bug/mistake either in your scan or post processing.
Maybe you try to rethink your workflow and let us know which of the possibilities above ( or another one i did not think about ) is the cause for the effect you are seeing.
Best regards,
Nils Heidorn
( partially repeating jheinzl's facts... )
normally the sharpness of a TIFF and a JPEG Image schould be very much the same ( if the JPEG Quality is set to a high value ).
Of course they are never the same as the JPEG introduces artifacts as it is a lossy format.
So if there is a strong difference and if the difference is not because of the compression artifacts, i'd say one of the following must be true:
-1- There was a different sharpness or focus setting between the two scans
-2- The film itself changed between the two scans. While this sounds strange it is a fact that e.g. a filmstrip gets warmer the more you scan from it ( high light intensity ) and starts bending, getting out of focus slightly more. ( This can be a problem for Multisample or MultiExposure scans, leading to the need of better fixture or using better film holders ).
-3- There is a bug/mistake either in your scan or post processing.
Maybe you try to rethink your workflow and let us know which of the possibilities above ( or another one i did not think about ) is the cause for the effect you are seeing.
Best regards,
Nils Heidorn
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