I don't know much about digital scanning, but I've been reading threads about this methodology. And I wonder, how does it really compare to flatbed scanning?

For simplicity, let's assume that one is using a full frame camera to scan a 35mm negative or transparency. Let's also assume that one is using a high quality, HM Schneider lens that is optimized for 1:1. (Best possible optic, intended for the purpose.) Given the above, let's see where "logic" leads us and what questions this "logic" might suggest.

RESOLUTION:

The arithmetic implies that, if one is using a 24mp camera, one is capable of "scanning" a 35mm at 4000 DPM resolution. Is this not well beyond the effective resolution of an Epson flatbed scanner? One can "specify" higher resolutions in Epson Scan.

But practically speaking, is this resolution achievable on an Epson 850 scanner?

Is it really achievable using digital scanning?

How does flatbed scanning methodology compare to "scanning" through a high quality lens? Better, or worse?

FLARE:

I've read recently that flare can be high in a flatbed scanner, especially compared to drum scanning. By comparison, I can imagine a setup using digital scanning, where flare can be kept to a minimum. So I wonder, can flare control be an advantage for digital scanning, as compared to flatbed scanning?

Again applying arithmetic, a 4000 dpm would enable one to print a 35mm frame to a 20"x13.3" photograph.

COLOR TEMPERATURE:

With flatbed scanning, it's my understanding that one has a single quality of light having a single, constant color temperature.

Yet with digital scanning, one could use one of those 35mm slide duplicators and control the color of the background light. Would this not be an advantage over flatbed scanning?

GAIN:

I've also heard that drum scanning technology enables one to control the "gain" in a scan, thereby enabling better shadow detail and control. And, this offers an advantage over flatbed scanning.

Back to using a slide duplicator as part of digital scanning, wouldn't being able to adjust the intensify of background light be similar to adjusting the gain used in a drum scan? At the very least, wouldn't the degree of control in digital scanning be an advantage over flatbed scanning negatives or transparencies?

So, lots of questions to ask. But, I'm beginning to suspect that digitals canning offers a huge advantage over flatbed scanning.

But, does it really?