copake_ham said:
Fact is - with the slides the scanner does not seem to be truly digitizing in RAW format the way it does with a digipic - like I would have expected (i.e. like re-shooting the pic - but this time as a digi).
Not sure what you mean by this. As long as you're scanning at the same bit depth and resolution, you should get the same quality regardless of the format you use to store the scan files.
There's nothing special about "raw" format itself (in fact, it's not actually a format -- it's just a file that stores unprocessed CCD data for later manipulation.) Being able to manipulate the data later is convenient when shooting photos with a digicam, since it lets you change the image-processing parameters when you get home -- "shoot first and ask questions later," you might say.
With a scanner, there's no particular advantage to it (unless it's handier for your image-storage workflow) since you can change parameters after prescanning, or even rescan the image if you didn't like your first settings.
So if you're not liking the quality of your results, it has to be something other than file format.
I suspect the issue simply may be that, like any analog storage medium, slides lose some information whenever they're translated from one form to another. That happens when you print a slide, and it also happens when the slide's image goes onto the scanner imager for digitization. You lose some information when going from the original scene to the slide, and then some more when going from the slide to the scanner's imager. That's two steps of loss, compared to only one step when shooting with a digital camera (where the image goes straight from the original scene to the imager.)
Scanned color negatives exhibit less such loss because they contain more information than a slide in the first place -- part of the thing I was talking about earlier, the fact that negatives have lower inherent contrast. The fact that the contrast is lower means tones are less likely to be "clipped" when stored on negative film (which is also why slide film is more critical about correct camera exposure.)
So, even though you still lose some information when scanning a negative, just as you do when scanning a slide, you're still left with MORE information because there was more in the first place.
You still can get satisfying results from a scan of a slide -- just don't expect it to look like an original digital capture of the same scene. You have to do a little "interpreting" when scanning a slide to make sure that the limited information available yields the pictoral effect you want -- just as you do when printing via Ilfochrome or any other process.