Having used both Canon and Epson 17" and 24" printers since 2003, I thought I might post some reflections about the world of large-format printing... I've owned two Epsons (a Stylus Pro 4000 and a 7900), and three Canons (iPF 5000 and 6100, plus my current Pro-2000) in those 15 years. The 6100 lasted 10 years, the first three with me, then a friend got another 7 out of it (it just retired because everyone I know uses Macs with newer OS releases that won't drive it). My personal preference is Canon, as an individual photographer who tends to print in batches and sometimes leave the printer off for weeks or even months in between. If you have the volume to keep an Epson from clogging, they too produce excellent results, with some significant advantages in paper feeding and minor advantages in certain colors.
In favor of Canon: The big Canons are not a whole lot more complex to maintain than a consumer 13" printer - you can turn them on and off pretty much at will, and it does whatever head cleanings it needs on its own (I've had a couple of them, and have a Pro-2000 now - all of them wake up nicely even after long absences). Longer-lived for the average individual photographer, because you are much more likely to lose an Epson to a head clog than to wear either machine out.
Canon heads are user-replaceable, which is a huge maintenance advantage - on older models, there were two $500+ heads, while the newest Pro series use one head that's only a little more expensive than one of the two in the older printers. For relatively light use, the heads last several years (print shops chew them up faster).
In favor of Epson: Current models have a straight paper path that is very easy to load, and will print on anything (including metal, plastic and supposedly even thin plywood!) May be more economical on ink if used heavily enough that it doesn't waste too much on cleanings, and the ink is somewhat cheaper. Supposedly more durable in heavy use (print shop) - the head isn't user replaceable, and lasts many years if you run enough ink through it, but clogs easily if idle (replacing the head is a $1500 service call, which often means a new printer, especially for 24" models) .
The HP Z-series, which I've never used, have a reputation for being unusually individual photographer friendly. They are big and heavy, but less so than Canon or Epson. Like Canons, they're "turn it on and go", even if you haven't printed in a while. They use a bunch of $70 heads instead of one $600 Canon head or a "toss the printer" Epson service call. Unfortunately, the old Z3200 is discontinued and becoming hard to find, while the brand-new Z9+ seems to have been released in the dark of night, but not to be in circulation (it's also $650 or so more than an Epson and $1000+ more than a Canon, depending on deals at the moment).
Both Canon and Epson have absolutely fantastic image quality today - Canon has closed the gap to nothing. The early Canons (iPF-5000 generation) had odd color gamuts, but that was gone by the x300/x400 generation, and the Pro-2000/Pro-4000 are very well behaved. Each has a slight image quality advantage in the particular colors where they deploy extra inks (Epson in saturated greens and oranges, Canon in blues and violets), but both are well beyond Adobe RGB across the color spectrum, and it's hard to record a color that is out-of-gamut for either one with a camera (it's more of an issue if you are doing very bright/saturated work in Illustrator).
Any 24" or 44" printer is a big commitment - they are big, bulky machines that take up a lot of space and clash with most decor. Even a 24" printer is a piece of furniture (think table-height bookcase, but it protrudes from the wall more - or a coffee table, but taller), while a 44" printer is about the size of an upright piano. The inks are much cheaper per milliliter than for smaller printers, but you have to buy a lot of ink at once - even the smallest-capacity cartridge is close to $100, and they take 11 or 12 of them in different colors (hopefully they don't all run out at once). Those expensive cartridges hold 10 or 12 desktop printer cartridges worth of ink or even more in the larger sizes, so they wind up half the price, but there is sticker shock when you run out of ink!
You need a high-resolution camera to print big with the detail these printers can deliver. A 24 MP camera with a really good lens will make a nice print on a 24" printer, but there is a substantial difference if you give it a bigger file (one of the 40+ MP cameras or medium format). I'm getting fantastic 24" prints out of the new Nikon Z7 - I am surprised by how much of a difference it makes compared to my 24 MP Fujis with excellent lenses. Any camera less than 24 MP is a more logical companion for a desktop printer, as is a 24 MP camera with less than excellent lenses (unless you have a somewhat unusual lens, any APS-C camera other than Fuji). What's holding most 24 MP APS-C cameras back is not the sensor, but the generally lackluster lenses - both Canon and Nikon make a few good APS-C lenses, but many more lousy ones. It's far more common to have a good lens on a 24 MP FF camera (or a Fuji, which have excellent APS-C lenses) than on most APS-C bodies.
To use the full size of a 44" printer with good detail, you need an ultra-high resolution camera and lens. The difference between 24 MP Fuji and 46 MP Z7 files on the 24" Pro-2000 suggests strongly that 24 MP won't hold up for critical viewing on a 44" printer. It will probably work on canvas, or not looking too closely at the print. Since I don't own a 44" printer, I haven't had a chance to try Z7 files on one yet. My best guess is that the best match for a 44" printer is either an ultra-high resolution FF camera (D850/Z7/A7r mk II or III) at a minimum, medium format digital or stitched files. I'm very interested to try a Z7 file on a Pro-4000 at full size.
These printers are 300 (Canon) or 360 (Epson) dpi machines, not the manufacturer-specified 2400x1200 or 2880x1440 dpi - the high number is for black and white line art. Since they produce color by putting down dots of different colors, the color resolution is much lower. They wiil scale files of different resolutions fairly well, but the best results come from scaling in software before sending them to the printer. Lightroom's print module has a very good automatic scaler - simply set the output dpi to what the printer wants. Qimage is another favorite way to print that also handles the scaling for you. If you're printing straight from Photoshop, it's worth it to resize the image to the printer's preferred dpi before sending. Both Canon and Epson have a double-resolution option (at highest print quality, they'll take a 600 or 720 dpi file and actually make use of it). It's not a true resolution doubling, but printing passes at a slight offset - it makes some difference, and is worth using if you'd otherwise be scaling your file down to reach the printer's native resolution.
A 24" printer out-resolves all current cameras except medium format at 300 dpi. The 24" Pro-2000 has 7200 color dots across the platen (the Epsons have 8760), while the highest resolution current 24x36 mm cameras are the Canon 5Ds/5DsR at 5792 pixels on the short axis, the Nikon Z7/D850 at 5504 and the Sony A7rII/A7rIII at 5304. These cameras give around 230 dpi at 24" - plenty on a print that size, especially using a good scaler like Lightroom or Qimage to get to 300 dpi. The heavily rumored 60 MP 24x36mm sensor would be around 6400 pixels on the short axis, while the highest resolution 24x36 mp sensor commonly discussed is ~80 MP (Micro 4/3 pixel pitch on a larger sensor) - that will be very close to the 7200 dots the printer asks for. An 80 MP 24x36mm sensor, while not beyond current technology, will probably have significant image quality compromises if it uses today's sensor designs. Micro 4/3 loses about two stops of DR to the best FF sensors at equal ISO, and another stop or more due to the low-ISO capability of some FF sensors - an 80 MP sensor with today's tech would be a big Micro 4/3 sensor - a ton of detail, but losing other aspects of IQ.
The highest-resolving medium format sensors can out-resolve any 24" printer absent the resolution-doubling mode. The 100 MP sensors presently found only in mind-blowingly expensive Phase One backs (but the Fuji GFX 100 will be in that class while remaining merely frightfully expensive) are right around the 8760 pixels of the Epson printers, while the unique sensor in the Phase One IQ4 150 is something like 10,600 pixels in the short dimension - more than any printer short of a 44" model.
It's important to match your camera to your printer - here's a very rough guide - I shoot high-detail landscape and print on highly resolving Baryta papers, so these numbers may suggest that you need more megapixels for a given print size than you see elsewhere - you can get away with less on canvas, and especially if the subject isn't detailed.
Screen and web use: Any interchangeable lens camera from the past 5 years or more, many fixed-lens cameras. If you're not going to print, you don't need resolution. Dynamic range and noise still matter... I can reliably spot a phone picture on the web or even in a thumbnail with many subjects - the extremely low dynamic range (or poor-quality HDR trying to compensate) gives phones away. The highest resolution screen in real circulation (8K monitors exist, but are almost never seen outside Hollywood) is a 5K iMac (14 MP). 4K monitors are about 8 MP, 27" non-4K monitors are about 4 MP, and everything else (as well as nearly every image on the web) is below 2 MP.
8x12" prints or smaller: Anything except a phone or a small-sensor compact (or a very old camera like a Nikon D70 - just tried editing some D70 files, and talk about funky color - we've got it good these days). I've tried to print files from iPhones and cheap superzoom compacts that people have handed me, and they really don't print well even at 5x7". The problem is everything except resolution - the files often have blown highlights, black shadows or both, and there's often a huge amount of noise. Something like a modern 1" sensor compact is what it takes to get me to even push the power button on the Pro-2000, and that'll go a little bigger than 8x12".
12x18" prints or smaller: Any interchangeable lens camera on the market today (and most going back five years or so), unless the scene has huge dynamic range. Relatively cheap desktop printers that print 13x19 are a good match for 1" sensor compacts with decent lenses, and for Micro 4/3 and APS-C with mediocre ones. You can get a printer like this for $50- $100 when you buy a Canon camera in a promotion that usually seems to be running, and it's a good match for the camera it came with (usually a Rebel or an EOS-M that is held back by its kit lens).If you replace that lens, the body will print 16x24" easily, and might push as high as 24x36". Many 13" printers (including the more affordable Canon models) use dye inks that fade more easily - models that use pigment inks for archival prints start around $500 if there's a special running at the time.
16x24" prints or smaller: Any interchangeable lens camera on the market today with a decent lens (very few fixed-lens cameras other than exotics like some Leicas and the Sony RX1 series). Junk lenses really show up by this size - and this means every kit lens below full-frame that doesn't say "Fujinon" on it. Put a decent lens on a 24 MP APS-C body or even a modern Micro 4/3 body and it'll print 16x24" just fine, even on a high-detail subject. 17" width printers are a significant step up in price from 13x19" printers ($800-$1000 and up, depending on sales), and all use pigment ink. Some look like 13" desktop printers except a bit wider, while others are bulky machines related to larger printers. Some will only make almost 16x24" prints because of required margins on 17x25" paper.
The other way to get 16x24" prints, which is cheaper in the long run, is from a 24" printer (printing across the roll or using a 17" roll). Roll paper is cheaper than big sheets, there are many more options, and the big ink cartridges reduce running costs. You can usually find a Pro-2000 under $2000 after rebates (and it comes with about $600 more ink than even the larger 17" models) - why pay $1000 for a 17" Pro-1000 that doesn't take rolls when you can get a Pro-2000 for $700-$800 more with $600 of extra ink, reducing the real difference to a couple hundred dollars?
One valid reason is that the Pro-1000 sits on a sturdy desk, while the Pro-2000 is a piece of furniture that clashes with most decor except "print shop" A second is that you have to pre-buy the $600 worth of ink (not a minor expense). The third is that the Pro-1000 (and most 17" printers) will serve as an office printer as well as a photo printer in a pinch - they generally have paper trays that will take 100 sheets of 8.5x11" office paper, and they have very decent running costs for word documents and the like. No presently available 24" printer has a tray for office paper - they only load it one sheet at a time (if you were really clever/desperate, you could use an 8.5" wide roll of plain paper, I suppose, but the prints falling into the basket would get out of order unless you also built a custom print-catcher - hardly worth it!). HP made a 24" hybrid in the early 2000s that both took office paper reasonably and was much smaller and lighter than most 24" printers - but I haven't seen anything like it in years (the roll feed didn't really work, and fixing it might have increased the size and weight)!
24x36" prints: We begin to lose currently manufactured sensors by this size (not to mention lenses!!!). The bare minimum is a modern 24 MP APS-C sensor, perfectly exposed at low ISO with an excellent lens. Many Fuji lenses are up to the task, as are some gems in other manufacturers' lines (and good FF lenses on a 24 MP APS-C body). 24 MP full-frame gives a little more flexibility, and good FF lenses are a lot easier to come by than good non-Fuji APS-C lenses. I've never seen a sub-24 MP file (or a sub-APS-C file) I'm comfortable printing at this size. A good 24 MP 24x36" print is impressive until you put it next to a good 24x36" print from a camera with extra resolution and dynamic range. The ideal camera for 24x36" is a 40+ MP FF pixel monster like a D850/Z7/A7r mkII or mk III (you don't need medium format, although 50 MP medium format is another excellent option). Their 36 MP predecessors also work very well...
Above 24x36": Nothing but pixel monsters (and medium format) need apply to make fine art prints this big! The 46 MP Nikons at 36x54" have almost the same resolution per square inch as a 24 MP camera at 24x36" - and a 36x54" print will be viewed from quite a bit farther away. Viewing distance becomes a huge factor with prints this large - if it's a poster instead of an art print, it doesn't need the resolution. The ideal camera for a 44x66" art print is either a 100 MP+ medium format monster or a multi-image stitch from something else.
The converse is also true - one of the few reasons to use a 100 MP+ camera is to make huge art prints that will be viewed from close distances. Anything less is wasting the image quality of the camera - why put up with the cost, size, weight and inconvenience unless you're printing so big that nothing else will do? Even the 40+ MP cameras make no difference compared to their more flexible 24 MP cousins unless you have a 24" printer and regularly use its full width.
