Resolution problem/scanning at 1200dpi but scans are 72dpi

[lauraw]

Hello

I have been scanning images with Silverfast SE 8 software on a Canoscan 9000F using the Workflow pilot assistant, for the last two years in the following way:

- Source:photo + Task:NoAutomatic + 48-24bit
-Under Scan dimensions I have used the preset: “1/4 optical resolution 1200dpi"
or “1/2 optical resolution 2400dpi"
- Under “File” I have selected TIFF
- I have not set anything else before making the scan except for the above settings

They are heavy files and the quality looks good to my eye but opening all of them in preview and photoshop, I have discovered that both programs say that all my images are actually 72dpi:

A sample dimension of one of my images scanned in the above way at “1200dpi” is 4495x13425 (185.5MB). In preview and photoshop it confirms these measures but says it is 72dpi

A sample dimension of one of my images scanned in the above way at “2400dpi” is 9098x26920(739.3.5MB). Again in preview and photoshop it confirms these measures but again says it is 72dpi

Please could someone explain what might be going on and how I can remedy this? I would like to know if have to remake all these scans to get the 1200dpi or 2400dpi desired (if so I do not understand how I can have such heavy images, with such large dimensions and the dpi be apparently so low) or is the dpi just being misrepresented for some reason in preview and photoshop?

Thank you very much

[LSI_Ketelhohn]

Dear customer,

That is the display rsolution set for the file. It has nothing to do with the actual scan resolution.
You do not need to rescan your images.

Kind regards,
Arne Ketelhohn.

[lauraw]

Dear Arne Ketlhohn

Thank you very much for your reply and apologies for the delay.
I am happy to learn this. Please can you tell me if the display resolution set for the file is something that is controlled in any way by the way I am using Silverfast and how I might change that in the future?
I ask this because some of my much older scans (made using the same silverfast software and version, with the same computer/and scanner never updated because on a computer not attached to the internet, scanned in exactly the same way as detailed, and now opened in the same programs as my newer files that say 72dpi) do say 1200dpi, although I did nothing different during the process. Therefore I am not clear what could have changed in the interim for the display resolution for all my newer files to be set differently.

Thank you

All my best
Laura

[LSI_Ketelhohn]

Dear Laura,

You can simply enter the scan resolution in the Preset.
Then the two values are the same.
If you can not set it make sure the Zoom in the Expert settings (gear wheel) is set to 100.

Kind regards,
Arne Ketelhohn