Page 1 of 1
Compression of pictures
PostPosted: Thu Sep 03, 2009 9:35 pm
by JaOl
I´ve noticed a peculiarity with my scans with Reflecta Crystalscan 7200 and Silverfast. The scans are compressed slightly i the short, 24mm, direction. 1~2%. Is there a explication for this? And can I do something about it?
Jan
Re: Compression of pictures
PostPosted: Mon Sep 07, 2009 1:01 pm
by LSI_Luebker
Dear Jan,
could you please tell what file format you are using ?
If you want to avoid compression at all I would suggest usinng tiff.
Re: Compression of pictures
PostPosted: Mon Sep 14, 2009 10:24 pm
by JaOl
I do save in tif. It´s not that kind of compression. The scan i slightly elongated comparetd to the original slide.
Re: Compression of pictures
PostPosted: Tue Sep 15, 2009 8:25 am
by LSI_Morales
Dear JaOl,
perhaps you did a resizing of the output file or changed the scale values while the proportion locks where unlocked and this caused your files being different than the original slide.
Cheers
Re: Compression of pictures
PostPosted: Mon Sep 28, 2009 8:54 pm
by JaOl
No, The scans is like that when they come in to Photoshop. But I have tried to scan with CyberView with exactly the same result so I think it´s a property of the scanner some how.
Jan
Re: Compression of pictures
PostPosted: Tue Sep 29, 2009 7:46 am
by LSI_Morales
Dear JaOl,
CyberView is the original scanner driver which is also used by SilverFast. If you mean this effect is also present there, most likely this is produced by the scanner. What I really wonder is: How are you able to perceive a 1% difference in an inch big negative?
Cheers
Re: Compression of pictures
PostPosted: Mon Oct 05, 2009 9:37 pm
by JaOl
It´s slight but more than 1%. I scanned a 24 x 24 slide and turned it around 90 degrees and did a new scan and mesured with the ruler in Photoshop. I also superinposed the pictures.
I actually noticed this first when I compared a inkjetprint with a C-print.
Cheers Jan
Re: Compression of pictures
PostPosted: Tue Oct 06, 2009 7:57 am
by LSI_Morales
Dear jan,
Since you have perceived the same effect using Cyberview, most likely the cause for this lies directly in the driver or the scanner itself.
Thanks for reporting, we will have it in mind next time we test the scanner.
Cheers