Resolution confusion?

[MBane]

First thing to say is this is only day 2 with Silverfast so it is all very new to me!

I have Ai Studio 8.5 running on Windows 7 64 bit. The scanner is a Braun FS-120, max resolution 3200dpi.

After a bit of looking around I have understood (I think) how to set the resolution of scans to 3200dpi (ppi). However, as shown in the screen shot, the Res. slider in the Scan dimensions frame is in the red suggesting the software thinks the scanner is beyond its native resolution.

Am I doing something wrong or is there something else at play I have not yet understood?

My aim is to scan my slides and negatives at the maximum resolution of the scanner.

Thank you!

[LSI_Ketelhohn]

Dear customer,

No you are doing nothing wrong.
It is just not suggested to use the maximum resolution as this often produces the most noise in the scan.

Kind regards,
Arne Ketelhohn.

[MBane]

Thanks, which begs the question what is the point of the maximum resolution of the scanner!

[LSI_Ketelhohn]

Sorry I'm not sure I understand your question.
The maximum resolution is the maximum number of pixels the sensor can produce.

Kind regards,
Arne Ketelhohn.

[Jossie]

Hi,

your scanner is produced by PIE, as is my DigitDia6000. For my scanner PIE told me that if one scans at the lower native resolutions, scan lines are skipped instead of averaged by the firmware. If one assumes that PIE's statement is also true for your scanner, which is quite likely, you get the best image quality, if you scan at maximum optical resolution and then bin to the desired resolution afterwards. You can easily verify this by scanning at maximum resolution and then bin and compare this to a scan at say 1/8 the optical resolution.

Here is such a test for my DD6000:

From left to right: Original scan at 5000dpi binned to 625dpi by PhotoShop, same but averaged 8x8 pixels, skipped 7 out of 8 scan lines, skip 7 out of 8 scan lines and 7 out of 8 columns, scan at 625dpi

Vergleich_binning_skipping_2.jpg (140.62 KiB) Viewed 1075 times

It is obvious, that the best result for 625dpi is obtained by scanning at maximum resolution and then bin.

Hermann-Josef Röser