Paul, I know this has been discussed a lot elsewhere, but I am not sure any area scanner can exceed the quality of a good drum. Depends on what you mean by quality. If it is resolution, then yes, perhaps, depending on the size of the film and your patience for stitching. If it is accuracy then no. Drums rule. That said, I don't think accuracy matters for photography, because the photos are creative interpretations of the real world. We manipulate lighting, camera settings, post processing - all to make photos that look good. A typical photo of a sunset is not what that sunset really looks like. Scanning is just another part of the creative process for a photographer.
If we want the best accuracy (using film as a quantitative or archival medium), the requirements can be different. I started out drum scanning 8 x 10 radiographic films. Did hundreds of those. Then I built a variety of CCD camera scanning systems because drum scanners were such a PITA, not because they gave inferior results.
When I sent some of my 8 x 10 photographs away for drum scanning (aargh, so expensive) the results were good and clearly more resolving at high OD values than what I could get from a digital back. I am not saying camera scanning is bad, or that an Epson 750 is junk. I am just saying drums have their uses and you might want to send a few of your best films out just to see what they look like from a drum.
I am impressed by what P1 does with its archival systems, and with what many photographers are doing with camera-based scanners. As you say, a properly set up camera system can yield great results. Horses for courses.
I really dug into this a while back, commissioning scans, etc. I would even have no problem going all the way and getting a big Dainippon with Xenon lamp in my basement if I felt the need.
So two things:
1) Accuracy – you really need to invest in your setup to get this one right - heavy duty repro stand, high end perpendicular negative holder with glass flattening or alternatively an air gun which pressed the neg against a surface before shooting. You could also use a flash to freeze capture moment in conjunction with a copal shutter or an Alpa FPS. I have heard of air pressure systems with flash, but get very good results with laser aligned glass holders.
2) Look – there's a difference in how the negs look as a combination of negative inversion profiles, light source (flextight is a cheap cold neon lamp for example with not so good CRI) and capture electronics (photodiades reading out RGB through old circuitry or the famed trilinear Kodak CCD used in IQSmarts, Flextights).
The main reason for me to get into drum scanning would be similar to the reason to do a C-Print – for colour representation of film based on yesteryear's look - that's it. For sharpness and detail, as long as you get your setup right which most don't - it has been superceded IMHO.
The problem with the IQ4 is that it captures too much detail and a a lot wider gamut than legacy systems. To get the saturation and gamut of legacy fine art prints you'd need to emulate a chain which chips off quality so to say at various stages in the pre-processing if you go IQ4-Injket vs. Heidelberg-C-Print. It is possible, but then again not, because the analogue chain has non-linear intra-relationships which are difficult to emulate via simple image profiling techniques which just capture the translation between two ideal states, but fail to account for non-linear fringe cases. Ie, high-key scan on Flextight and overxposed portra, printed carefully via an experienced operator, etc.
Sharpness - I can very quickly do a 2-way stitch of a 6x7 neg via laser alignment which blows away the Heidelberg equivalent. The colours though ... it looks different, not better or worse. And that different looks like the stuff in museums ... so this is why I'd still get a drum scanner. Just for the look.
The main reason you'd want to fork over 20k for a Flextight X5 today is to get the flat look the system gives your from scans which you can achieve via repro scanning, but it will take you a lot of post processing for each shot while the Flextight is effortless and looks like fine art as it has been ingrained in our collective memory from countless gallery visits and fashion adverts.
There's a reason the wet dream - pardon my language - of a photography BFA is to own a Flextight and not an IQ4 and a repro stand. The scans just look fine art every time. Effortlessly.
