I've read through many of the archived threads on scanning, but still have the following question.

Looking at Silverfast AI or Epson Scan for the 4870, there are multiple image adjustment capabilities, including curves, levels, unsharp mask, color adjustments and the like, that are also available in Photoshop. To obtain the best scans, which of these should be applied in the scanning software, and which should be applied in Photoshop. Or, does it matter?

It's my understanding that the adjustments in scanning software for scanners like the Epson 4870 or 4990 flatbeds do not affect gains, they only numerically affect the resulting digital file. So, if I were to follow my instinct on scanning workflow, I would adjust only those that relate to scanning directly, like resolution, whether to invoke digital ice, bit depth, and the type of film using the scanner software. I would adjust the other attributes like levels, curves, sharpening, color balance, etc., post-scanning in Photoshop which has greater flexibility in these tools.

Is this strategy correct? More advanced scanners do directly affect gains (as I undersand it), so the optimum scanning workflow would be different. But, my interest is in the medium priced flatbed scanners like the 4870 or 4990, since this is what I and many others own.