A Simple Question re resolution/quality settings

[steve_dc]

I plan to use my scanner and the Silverfast software simply to create a file for further processing in Lightroom or Photoshop. I will not be relying upon Silverfast to output to media, such as the web or a print. As a result, I don't think I have to worry about the simple, yet difficult to understand topic of dots per inch on the screen, dpi, and lines per inch resolution on the printer, lpi. I am trying to produce the scanner equivalent of a RAW file for further processing.

Here is my question:

What are the correct settings if I want to create files that have the same resolution as those I download from my digital camera?

For example, one of my cameras puts out 10.6 mb files, having a sensor of about that size. I assume there is absolutely no more information in those digital camera files than that 10.6 mb of data. Is it sufficient simply to set the dpi slider to produce a file of approximately that size once I have set the frame lines for the image? In other words, set the dpi slider to produce a 10.6 mb file, or close to it. Do I have to take into account pixel count, horizontal and vertical, on the camera sensor to achieve comparable resolution using the scanner? Camera sensors vary in the size of the units that sense photons and in their spacing. Is the best way to think of the question to assume the scanner is just another camera, and it can't produce better resolution than the film it is photographing? If so, should I try to determine the resolution of the film itself and use that somehow in setting up the scanner? I am scanning using the Nikon 5000 ED scanner, scanning slides and 35 mm film strips.

Thanks in advance.

Steve

[LSI_Ketelhohn]

Dear Steve,

The Scanner works differently than a Camera.
It does not produce "raw" data like the camera sensor.

The best way to produce scans for your purpose would be to set the output size to the same size as your camera images.

kind regards
Arne Ketelhohn

[degrub]

The test results i have seen for the 5000 suggest an optical resolving capability of around 2700 ppi. Any scan above that is oversampling and might result in artifacts. i generally scan at the sensor capability - 4000 ppi and down sample to whatever resolution i need in PS. Unless i try to enlarge too much, i don't see any visual issues, just occasional moire.

Do you truly want a "raw" scanner output file ? HDR48 bit output is a way to get that. Do you want to use the dust/defect detection and removal features of the scanner ? That would have to be done with the scanner software or HDRi. PS is not pre-set up to easily apply the infrared channel, although you can do it.

i don't know what bit depth you are working with in your cameras, but the 5000 will produce 16 bits per color channel - ie 48 bits per pixel, so the size of the file in MB for a given LxW number of pixels may be different for the same pixel count from your camera sensor. The additional infrared channel adds another 16 bits per pixel

Since any PPI below 4000, unless divided by a multiple of 2, will be interpolated you can choose to do that in SilverFast or PS to get a close match for the camera sensor total pixels if needed.