Plustek 8200i true optical resolution question

[Paul-H]

Hi all

A quick question, I hope

I have a plustek 8200i Film scanner which the makers claim has a resolution of 7200dpi, but when I use the Supplied Silverfast 8 SE Plus software that claims the maximum resolution is 3600dpi with a recommended resolution of 2400dpi.

Anyone know what the true optical resolution of this scanner is.

Thanks

Paul

[LSI_Ketelhohn]

Dear Paul,

Please make sure you are using the latest drivers and the latest SilverFast version.
The offered resolution depends on the values the driver offers.
Maybe the driver on your system is outdated.
For Windows you can download the driver from the Plustek website.
For Mac OS X systems the driver is included in SilverFast.


Kind regards,
Arne Ketelhohn.

[Paul-H]

Hi

Thanks for the reply

I am using the latest drivers, downloaded from Plustek

Thanks

paul

[LSI_Ketelhohn]

Dear Paul,

I just checked and on my System the 7200 ppi resolution is selectable.
Have you tried resetting SilverFast through the welcome screen's service dialog?
Maybe the settings files got corrupted.


Kind regards,
Arne Ketelhohn.

[Paul-H]

Hi

Like you I can select 7200 but the selector is now in the red section which according to your documentation found here http://www.silverfast.com/newsletter/in ... on/en.html means its in the interpolated range and not its true optical resolution, according to the slider the optical resolution, shown by the green area has a maximum of about 2400dpi.

if the scanner has a true 7200dpi resolution why does the resolution selector not show green all the way to 7200dpi.

Thanks for your help with this

Paul

[LSI_Ketelhohn]

Dear Paul,

SilverFast gets it's resolutions directly from the scanner's driver.
You can for example use a USAF resolution target to measure the true maximum resolution of your scanner and simply use that value for your scans.


Kind regards,
Arne Ketelhohn.

[Paul-H]

Hi

Thanks for confirming my thoughts that the Plustek 8200i only has a true optical resolution of 2400dpi as confirmed by your Silverfast Software.

Paul

[Paul-H]

Hi

I contacted the plustek customer support over this Resolution Issue and they replied that the True optical resolution of their 8200i Scanner is 7200dpi and not the 3600dpi as reported by silverfast.

Will Silverfast be updated to correct its reporting error.

Thanks

[LSI_Ketelhohn]

Dear Paul,

The resolutions are all represented in SilverFast.
A correction is not necessary.
There is just simply no interpolated step, because Plustek asked us to show only the hardware resolutions.

Kind regards,
Arne Ketelhohn.

[Serhii]

Dear Arne,

I also find this confusing, because as Paul has already stated

I can select 7200 but the selector is now in the red section which according to your documentation found here http://www.silverfast.com/newsletter/in ... on/en.html means its in the interpolated range and not its true optical resolution, according to the slider the optical resolution, shown by the green area has a maximum of about 2400dpi.

So, I would like to reiterate on the same question Paul asked, which I think is still not answered: if the scanner has a true 7200dpi resolution why does the resolution selector not show green all the way to 7200dpi?

[LSI_Ketelhohn]

Dear Serhii,

7200 is a physical resolution.
For this device we do not offer an interpolated resolution.
That was a request by the manufacturer.
This device is a special case.

Kind regards,
Arne Ketelhohn.

[Serhii]

I understand that there is no interpolation option for this specific scanner, and I think this is just fine taking into account the optical capabilities of the scanner.

My concern is not about the lack of interpolation option, but is rather about misleading documentation OR misleading user interface which suggests that everything over 3600dpi would be an interpolated resolution which is clearly not the case as you explained. I expect that the colour of the bar below resolution slider is adjusted automatically in accordance with true capabilities of the scanner it works with.

[LSI_Ketelhohn]

Dear Serhii,

I have forwarded your remarks to our product management.

Kind regards,
Arne Ketelhohn.

[MartinN]

Dear Serhii,

7200 is a physical resolution.
For this device we do not offer an interpolated resolution.
That was a request by the manufacturer.
This device is a special case.

Kind regards,
Arne Ketelhohn.

Please, please do NOT change these resolution sliders and coloration.

The 7200dpi of Plustek scanners is the optical resolution of the sensor.
But it is so easy to confirm the true resolution of a scanner by a USAF-1951
test chart from Lasersoft. I have measured my 7200ppi Plustek sensor and
have easily deduced that the good resolution from this sensor is about 3600ppi
and if I would really push, I could see some resolution up to about 3900ppi.

The Short story is as follows - You can never get 7200ppi resolution from a 7200ppi sensor.
So using 7200ppi is unnecessary and bloats the file. 7200ppi is only for marketing talk and
cannot be reached due to MTF and Nyquist's sampling theorem.

In my opinion Silverfast SHOULD advise users to use at most about 4000ppi for a Plustek
7200ppi sensor and advise against using the unnecessary 7200ppi setting. The coloration
and function of the resolution slider is optimal as it is now, in my opinion.