My desire is to end up with a scan file that can be manipulated as much as possible in Lightroom and other post processing programs. Should I scan/output in RAW or TIFF?
This is what I do. I scan with VueScan and a Nikon LS-5000, output a raw file, open it in Lightroom, work a bit on it and finish the work in Photoshop.
I created an ICC profile of my scanner - a scanner profile not to be confused with a film profile.
My VueScan settings:
Input - Media: Image (this doesn't apply ANY film curve or film profile to the image and does NOT invert negative images).
Color - Scanner color space: ICC Profile
Color - Scanner ICC profile: points to the scanner profile (the file obtained while profiling the scanner)
Color - Scanner IT8 data: points to the relevant data file distributed with your scanner target (I don't understand why this is asked, as it should be used by VueScan only during the scanner profile creation)
Color - output color space: device RGB
Color - Monitor color space: sRGB (I do profile my monitor, my monitor profile is loaded at startup (WindowsXP) and is used at "system level" and valid for all applications. If you use a Linux-based system, with no colour management at system level, here you would use ICC profile and point to your monitor profile). In any case this options is only needed to generate the image on screen in the "Preview" and "Scan" windows of VueScan, it does not affect the scan file.
Color - Color balance: Neutral (the scanner sets black and white points), or None (the scanner doesn't even try to set black and white points) according to taste.
Output - Raw output with: "Save". I use ICE at minimum level. Option "Save" uses ICE and gives an image with "reduced" dust/scratches. Instead when using option Output - Raw output with: "Scan" the infrared channel is saved on the TIFF as a separate channel.
I don't tick the "Raw save film" option as I don't want VueScan to apply its own "film specific curves" to the RAW.
I create a DNG-raw when I scan slides. This file embeds the scanner profile, which Lightroom honours.
I create a TIFF-raw when I scan negatives. As I use Input - Media: Image VueScan does NOT make the colour inversion and I end up with a negative TIFF file. I invert the negative using a Photoshop plugin, ColorPerfect by CFSystems which IMO works better than the inversion made by Photoshop.
Some additional notes:
If you create a scanner profile using VueScan, you obtain a profile .icc file and this profile with the configuration above will be embedded in the DNG-raw and will be "honoured" by Lightroom.
If you create a more complex scanner profile using a program like SIPC, and obtain an .icm file and configure VueScan so that it points to this .icm file the resulting profiling will not be present in the final scan (I don't know if this is because VueScan doesn't embed a SIPC profile or because Lightroom doesn't understand it, what I see is that the result is identical to what I obtain with the VueScan setting of "built-in" calibration, i.e. no external profile applied).
So if you want to use a complex profile like those .icm profile obtained with SIPC you have to generate a TIFF-raw, open it in Photoshop and apply the profile using the Photoshop function.
I find the simple way (profile .icc created by VueScan and embedded by VueScan in a DNG-raw) works very well with Lightroom.
To answer the original question, in VueScan raw and TIFF can coexist. You can have a TIFF-raw and a DNG-raw. The DNG will not be "really raw" if you use options such as embedding scanner profile, or if you use Raw output with: Save which embeds the result of ICE correction, or if you apply VueScan film curves, or if you apply your own film profiles, or if you use Color Balance: Neutral which sets black and white points... it's not raw is semi-cooked.
The TIFF-raw is basically the same file as far as the information is contained, but being in TIFF format can be opened with Photoshop. I use DNG-raw with slides, which I open with Lightroom, and use TIFF-raw with negative, which I open directly with Photoshop.