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Silverfast AI 8 - PPI question and noise problem

PostPosted: Wed Aug 10, 2016 5:06 pm
by soerdal
Hello all,

I hope there are someone who can help me answer a few questions. I have just changed scanner and software from Epson v750 and Epson SCAN to Plustek 120 and Silverfast. So far I like silverfast, it's easy to use and has alot of great tools.

1. Question about PPI. So i can manually put in the PPI in the preset box. For some reason the maximum PPI I can put in, is 1200. I know the scanner itself can do a max of 5300. What I can do is to drag the Res. bar in silverfast up to a higher PPI but when I import the file into photoshop it is the PPi that I put in the box (preset box) that seems to transfer into the data of the image. So is there any way to fix this? or is there something I am not aware of? How can I acutally scan at 5300 PPI and get that information in photoshop as well?

2. I am getting a great deal of digital noise in the images I scan. I understand that scanners will give me some noise, but I am looking at two identical images scanned with the different scanners. 1 scanned with the Epson and the epson software, and then the same image scanned with the plustek and silverfast. The one scanned with silverfast+Plustek has way more noise then the other. I am not talking a little bit, it's a lot. What can this come from? At the moment I am so happy with the Plustek and the Silverfast in every way except the actual image I am getting out of it, which is the whole point. I just hope there is something I am not understanding that gives me these problems as I hope I can continue using them together.

Many thanks

Re: Silverfast AI 8 - PPI question and noise problem

PostPosted: Tue Aug 16, 2016 9:38 am
by LSI_Ketelhohn
Dear user,

The Preset is the base display/print resolution for calculation display/print sizes.
The actual scan resolution is set by the slider below it.
The preset is also stored as the base resolution in the images metadata.
You can set it at the same size as the scan resolution if the scaling/zoom in the expert dialog (gear wheel icon) is set to 100%.

The background noise is always a function of the device. In SilverFast Multi-Exposure can be used to greatly reduce this.
Additionally there are software filters that mask the noise. Those are often activated in manufacturer software by default. But as these can reduce detail in a scan SilverFast has not activated them by default. GANE can be activated to reduce noise software sided.
Also when comparing scans make sure you compare uncompressed image files. image compression can mask the noise but of cause can also reduce image quality.

Kind regards,
Arne