Re: Best Film For Scanner Comparisons...
I don't see how a scanning test would be useful with only one film being tested. Unless the readers only use one particular film, the results would be quite narrow in scope. It would seem that a range of films would provide a better comparison, especially considering the diverse nature of current films.
If you are testing resolution, it seem to me that using a few B/W films would be much better. You could include a comparison of the resolution tests done by C. Perez and others.
Kodak E100VS has a different colour palette than Fuji Velvia. If you are testing colour response, then it might be more useful to test both films. Fuji Astia 100F is very low grain, though perhaps testing a grainier film would also tell quite a bit; the chance of grain affecting noise would be one aspect.
In a work environment, the end printed medium is always a consideration. Depending upon printing requirements, a given scanner might be beyond the capability of a chosen printing method. One thing I have noticed with some consistency is that colour can be more judgemental than sharpness or resolution for many clients; a slightly soft image would not be as problematic as one in which the colours were off or one that was too dark in shadow areas.
The first thing I evaluate in scanning systems is the Dmax. Unfortunately in consumer level scanners the numbers are often way off reality. After checking Dmax, then I look to see if enough true (not interpolated) resolution capability is present.
Another factor is the camera and lens. There will be variation amongst lenses, and some medium format lenses providing greater resolution capability than some large format lenses. You might consider using a Mamiya 7 and one of their well regarded lenses. Another possibility is an optical test using B/W film in each system, then seeing how close each scanner comes to matching the film results. If you want to avoid using cameras, then Kodak (Q-60) and Fuji have targets you can use for scanner testing.
Ciao!
Gordon Moat
A G Studio
Re: Best Film For Scanner Comparisons...
The problem is that every slide film that I'm aware of exceeds the DMAX capability of every consumer scanner on the market, and most do so by a considerable margin. That means that no matter what, you will exceed the range of levels that the scanner can see, so in this respect, you initial logic is a bit off.
If you were to use B&W negatives, it would be possible to make some that have a DMAX lower than tat of the consumer scanners, but then there is a whole host of other problems that crop up.
So when you want to discuss shadow detail with a chrome, you for the most part are really discussing the DMAX value in an indirect manner, not the number of actual levels that can occur in the shadows.
---Michael
Re: Best Film For Scanner Comparisons...
As currently planned you are stacking the deck against getting results that have much value. Mixing up all the parts of the imaging chain in your test leaves many questions unanswered and leaves you with "when Bubba scans his 4x5 on his flatbed his Epson prints look better than my Nikon 9000 scanned prints from my roll film back."
I have some suggestions:
Isolate the particular characteristics you are testing for and then devise a test that uses a known value or reference material. Use the same reference for all scanners. To further nail down the reference you might have it scanned by the best drum operator you can find.
One thing to test might me sharpness. A good way to do this is to use a the same resolution target film for all scanners. That would likely mean the same roll film negative or positive in all scanners. (I assume you have no interest in 35mm).
For testing color rendition use one of the charts Gordon mentions above. Again, use the same one in each machine.
For density range and dMax use a step wedge, again the same one in each machine.
Stouffer has some targets that will help you.
http://www.stouffer.net/
After doing the above is the time to do your workflow to workflow comparison to see if you can beat Bubba's 4x5 film on the flatbed. :D
If you use
Re: Best Film For Scanner Comparisons...
Scott - I have a set of Wolf Foust IT8 films in several emulsions, Velvia 50 +100, Provia/Astia, Ekta... They are 35mm, but they have 21 step wedges, color scales, and known densities for each square in the target.
See http://www.targets.coloraid.de/ Look for Set S1.
You're welcome to use them.
Kirk