48 -> 24 bit scan mode / too late to go back?

[JGArchive]

I've (accidentally) scanned a large batch of photos in 48 -> 24 bit color mode instead of 48 bit mode, but the whole time, I've had the densitometer under "expert settings" set to 16 bits.

1) Does the fact that the scans were output as 24 bits override the 16 bits/channel densitometer settings, effectively bumping it back down to 8 bits/channel in the final image?

2) Or could this possibly mean that, if I change the images from 24 -> 48 bits in PhotoShop (or, to use Adobe's preferred nomenclature, from 8 -> 16 bits/channel), there is enough color information in my photographs for the change to have an effect?

I suppose my ultimate question is: Since the images were scanned in at 48 bit, is that color information somehow recoverable (even though they were output at 24)?

Any help is appreciated.

[LSI_Ketelhohn]

Dear customer,

The densitometer setting has no effect on the image.
It only switches the measurement values in the densitometer window.
If you set the output to 48->24 the images will be saved as 24 bit images (8 bit per channel).

Saving the image as 48 bit in Photoshop will not revert the image back.
The information which has not been saved can not be restored without rescanning the image.

kind regards,
Arne Ketelhohn.

[JGArchive]

Thanks for your reply. May I ask, then, what is the purpose of scanning at 48 bit if it is converted to 24? Why isn't there just a 24 bit scan mode?

And, if I am scanning in 48 bit mode (which I am, now), does the densitometer still have no effect on the image? Or, should I always make sure it is set to 16 and not 8?

Thank you.

[LSI_Ketelhohn]

Dear customer,

24 bit is the standard bit depth used for most images.
JPG for example can only store 24 bit information.
Also only professional Software like SilverFast HDR (Studio) and Photoshop can process 48 bit images.
Other software might not even be able to display these files correctly.

Internally SilverFast always uses 48 bit data for processing.
Only the final result will be stored in 24 bit.

The densitometer is only a measurement tool.
It has no influence on the image.
Switching between 8 and 16 bit here only influences how the densitometer displays the values.

kind regards,
Arne Ketelhohn