The question you should have asked would be: given that I want to print good quality B&W prints of the size "XXX", which scanner do I need?
I will help: I print using Epson printers, which like to have the input defined as multiples or inverse multiples of 720. I tried to see if there was a discernible difference between 360 and 720 dpi, but even under a loupe it is difficult to distinguish, so I've settled on 360 dpi.
This means, that if your scanner actually resolves 3600 ppi, you can multiply the dimension of your negative in print by 10 times. E.G. a pano neg of about 1x3 inches will give you first rate print of 10x30 inches.
If I recall correctly, Epson V 700-800 resolves about 2200 ppi, so you can only enlarge (2200/360=6.1) 6 times, Imacon 848 0r X1,5 will give you almost 8000 ppi, so you can enlarge more than 20x. Most other decent scanners will fall in between.
Read this:
https://luminous-landscape.com/wp-content/uploads/2015/02/The-New-Epson-V850-Pro-Scanner-Final.pdf
it’s certainly worthwhile to read the article on the Epson V850 that you’ve linked, but finding a scanning solution is not as simple as you imply. One example: the V850 article gives some maximum print sizes but qualifies those as being “without downsampling”: indeed, Epson printers can make good, large prints with an input of substantially less than 360dpi — depending on the aesthetic that one is after, such as fine landscapes vs high-contrast street photography (say, Ansel Adams vs Moriyama Daido) an input of 180dpi, or even 120dpi, for huge prints (40x60 inches, or 100x150cm) can be fine.
Having looked at scanning solutions for a couple of weeks, it’s seems to me for many people it’s not as simple as deciding on the size of print that you want. Ideally, one would want to be able to make a quick scan of a roll of 35mm film and then make high-resolution scans of the “keepers.” But here’s where the problems start: what are “keepers?” For me there are two level of keepers: in the first instance, taking the three rolls of Tri-X that I shot a few weeks ago, there were 21 frames that I was interested in exploring further by working on them in Lightroom and Silver Efex (including burning and dodging), the equivalent of making “work prints” in the dark room. Then, there is the second stage of keepers that may be determined as long as 3 to 6 month later — and these keepers may average 2 per roll (“fine prints” in the darkroom). Added to this is the complication that I don’t know the print size that I may eventually want for any particular print: it may be, say, 12x18 inches, 24x36 inches or 40x60 inches.
In the dark room one can always pick up ant frame form any roll and make a work print or a fine print that one wants — and use a custom printer for the largest size. In scanning, the solution would be make a high resolution scan for all the first level of keepers and then use that for writing whatever size one wants. But this approach works only with an Imacon or Hasselblad scanner, in terms of resolution and dMax that one would want.
Now, I have an Imacon Precision III that I hadn’t used for ten years and gave it to a friend in December, when I was “sure” that I would never do film again, but he couldn't get it going — it has a SCSI interface — and returned it to me recently. In three 10-hour days, I managed to get the old OS X 10.6.8 installed on an old Mac PowerBook to run the (legacy) Imacon ColorFlex 4.04 software and got the SCSI-to-FireWire Orange Converter and Granite (power) SCSI Terminator going so that all this works — only to learn, on the third full day of my effort, that this scanner, which does true optical resolution of 6300dpi with a dMAx of 4.2, loses sharpness at the trailing end of the 35mm frame (as the negative is fed into the scanner in portrait orientation). Further research showed hat Imacon scanners require periodic maintenance fairly often. After some hours of searching the web, I found out that the cause of the sharpness loss is slippage of the drive belts the feed the holder mechanism. I have to replace these belts. Although, apparently, I can buy the belts in the US or the UK at about US$5 each, I'm likely to give up because these scanners usually require belt replacement every six months or so. The belt problem also makes the film frame shift in the holder as it goes into the scanner, so that a small portion of the scan is often cut off. I now remember from ten years ago that I often had this problem, but didn't know there was a solution. By the way, there is no batch feed solution for this scanner — and one full res (6300dpi) 35mm scan takes 15 minutes.
As I don't want to make a career out of the care and feeding of this Imacon scanner, I'm likely to just dump it. I couldn't sell it with a good conscience. Basically, even if I was prepared spent $14,000 on a new Hasselblad X1 — same 6300dpi resolution as my Imacon but twice the speed — I don’t think it would make sense because I don’t believe the the drive mechanism on the new scanner has changed. That means these Hasselblad scanners only make sense (beyond the price issue) in a photo lab environment, if they can be serviced and maintained regularly.
Other possibilities? According to the V850 article there are good Minolta and Nikon scanners, but these can be bought only used; they are old; they could break down; service might be difficult or impossible to arrange, depending on the country you are in. That leaves the Plustek and the Epson scanners.
I thought of getting a Plustek 35mm scanner, but am concerned that the dMax is only 3.6 — that’s 2 stops less than the my Imacon, whose dMax is 4.2 (0.3 = 1 stop)— you can get to 4.0 dMax using the SilverFast software with multi-pass scanning, but that takes 30 minutes per frame. The Plustek 8200 ai (US$500) has only manual feed. The Plustek 120 (US$1,900) has batch feed but the same resolution and dMax as the Plustek 8200 ai — but the batch feed, according to some reports, does not operate reliably, sometimes freezing the software.
The other alternative is an Epson V850 — slightly less resolution but more dMax (4.0) than the Plusteks and faster. Perhaps this could be the most practical (on the basis off all I’ve read on the subject), but not a great solution for large prints.
All these issues would fall away if I would make darkroom prints, but I simply can’t. A good custom lab is another solution. BTW, here in Paris, where I am right now, there is custom lab that will develop film by inspection and make a contact sheet or scan for €20-25 per roll; they can also make huge darkroom prints with barbing and dodging, as requested.
It seems to me that the lack of a good scanning solution is the single things that holds back most people that are interested in shooting film. The problem is that the film scanner market is just to small for serious scanner development by manufacturers.
I’m considering a full return to film — for the time being I’ll use a lab for developing and scanning. Not sure what I’ll do eventually. Am I missing something?
