Regardless of the number of nozzles and technical details of each printer, the proof of the pudding is the viewing. I am viewing three prints of the identical picture in front of me. This picture was taken on an older Canon Powershot G2, shot in RAW, processed in Adobe Photoshop Lightroom 2.1, and printed using Qimage to optimize the output to the native dpi of each respective printer. Each printer was custom profiled using 1000 color patches with Spyder3 Studio.
The papers were Dollar store variety for the Epson and Kirkland Professional Glossy. Inks used were by Precision Colors and each formulation as recommended by Image Specialists. Non OEM ink as most on this forum would use since it is principally a refilling forum.
This informal test intrinsically maximizes the capability of each printer so that none is hobbled with suboptimal color matching. The printers used were an Epson R220 (same engine as an R300), Epson R260 and an MP500 same engine as an iP4200.
The first thing I will tell you is that None of the prints are drastically different to 95% of the viewers. In other words I doubt that you'd be able to tell which one is which if you picked them up. Thus the output is basically the same to the general consumer AS we would and should expect it to be.
Using a loupe or magnifying glass when we look at the details, the differences then appear but only if we look for them or know where to look.
The color tone is slightly different for the sky between the Epson and Canon. (An area of compromise in Inkjets) Now this very interesting. Why? Because the inks that the R260 and R220 used are very different in shades yet they outputted the sky very very similarly. The Canon was different. this tells me that Epson intentionally chooses to sacrifice gamut here to output a certain shade that they think is a good compromise. Canon has chosen a different compromise. Both brands are not perfect, it's a matter of subjective taste here.
The next area I looked at carefully is the granularity of the gradients within the clouds and sky gradients. First off the R220/R200/R300 is an older printer and the oldest one amongst all three. Viewed with a loupe one can see some granularity in the sky and some dots in the shadow areas. However, to the naked eye, it cannot be seen. The R260 is grainfree. Even with a magnifying glass. The engine used is Epson's latest dye inkjet photoprinter. The Canon is interesting here as it is grainfree as well in solid shades and most colors BUT when the gradients are viewed carefully, one can perceive some splotchiness that is not there with both the older and newer model Epson. Could the use of only 4 colors be the cause of this? I'm not sure as I don't have an iP6600 for comparison. Suffice to say that both the old R200/220 with larger droplets and the newer R260 do not exhibit this. So droplet size is not causing this. It's likely due to a non linear profile because of the limited range of ink colors available on the iP4200.
Finally, in another series of images. I have noted that the Canon is weak on brown tones with limited range in that area. The oldest R220 is the best here. The Canon is superior in the green shades though, rendering lighter shades of green better but darker shades of green appear weak.
In conclusion, I think that if a decent photoprinter even one more than 5 years old is properly set up for printing photos, the output will be indistinguishable from the output from the newest models of today for the average consumer. The technical details of droplet size, number of nozzles etc. are not final determinants of the output quality. These specs are for marketing reasons in an attempt to sway a potential purchaser. The newest printers do possess greater speed and are quieter. The nozzles do play a large part in determining speed.
Ink formulations paper choices and proper color profiles are extremely important in determining output quality.
FINALLY If you see comparative output of the same image between two or more printers that are obviously very different to the eye, then you should be aware that either one is not set up properly or the color profile or ink formulation is way off or potentially BOTH or all are not set up properly. thus the comparison might be invalid. When they are all set up properly the differences are not and should not be dramatic especially with today's newer printers.
Have we plateaued in inkjet technology? I think we are getting there. More and more, it looks like the mfrs will be playing with different shades of ink to emphasize a certain color range and then compromising in another range. If anything, the R220 is superior to the R260 in brown tones yet is four to five years older. Are the multicolor printers like the Pro9000 better? Yes, provided the range of colors you want to output is outside that of your current printer. With an image with limited colors, the output may look no different at all. So it depends.
The papers were Dollar store variety for the Epson and Kirkland Professional Glossy. Inks used were by Precision Colors and each formulation as recommended by Image Specialists. Non OEM ink as most on this forum would use since it is principally a refilling forum.
This informal test intrinsically maximizes the capability of each printer so that none is hobbled with suboptimal color matching. The printers used were an Epson R220 (same engine as an R300), Epson R260 and an MP500 same engine as an iP4200.
The first thing I will tell you is that None of the prints are drastically different to 95% of the viewers. In other words I doubt that you'd be able to tell which one is which if you picked them up. Thus the output is basically the same to the general consumer AS we would and should expect it to be.
Using a loupe or magnifying glass when we look at the details, the differences then appear but only if we look for them or know where to look.
The color tone is slightly different for the sky between the Epson and Canon. (An area of compromise in Inkjets) Now this very interesting. Why? Because the inks that the R260 and R220 used are very different in shades yet they outputted the sky very very similarly. The Canon was different. this tells me that Epson intentionally chooses to sacrifice gamut here to output a certain shade that they think is a good compromise. Canon has chosen a different compromise. Both brands are not perfect, it's a matter of subjective taste here.
The next area I looked at carefully is the granularity of the gradients within the clouds and sky gradients. First off the R220/R200/R300 is an older printer and the oldest one amongst all three. Viewed with a loupe one can see some granularity in the sky and some dots in the shadow areas. However, to the naked eye, it cannot be seen. The R260 is grainfree. Even with a magnifying glass. The engine used is Epson's latest dye inkjet photoprinter. The Canon is interesting here as it is grainfree as well in solid shades and most colors BUT when the gradients are viewed carefully, one can perceive some splotchiness that is not there with both the older and newer model Epson. Could the use of only 4 colors be the cause of this? I'm not sure as I don't have an iP6600 for comparison. Suffice to say that both the old R200/220 with larger droplets and the newer R260 do not exhibit this. So droplet size is not causing this. It's likely due to a non linear profile because of the limited range of ink colors available on the iP4200.
Finally, in another series of images. I have noted that the Canon is weak on brown tones with limited range in that area. The oldest R220 is the best here. The Canon is superior in the green shades though, rendering lighter shades of green better but darker shades of green appear weak.
In conclusion, I think that if a decent photoprinter even one more than 5 years old is properly set up for printing photos, the output will be indistinguishable from the output from the newest models of today for the average consumer. The technical details of droplet size, number of nozzles etc. are not final determinants of the output quality. These specs are for marketing reasons in an attempt to sway a potential purchaser. The newest printers do possess greater speed and are quieter. The nozzles do play a large part in determining speed.
Ink formulations paper choices and proper color profiles are extremely important in determining output quality.
FINALLY If you see comparative output of the same image between two or more printers that are obviously very different to the eye, then you should be aware that either one is not set up properly or the color profile or ink formulation is way off or potentially BOTH or all are not set up properly. thus the comparison might be invalid. When they are all set up properly the differences are not and should not be dramatic especially with today's newer printers.
Have we plateaued in inkjet technology? I think we are getting there. More and more, it looks like the mfrs will be playing with different shades of ink to emphasize a certain color range and then compromising in another range. If anything, the R220 is superior to the R260 in brown tones yet is four to five years older. Are the multicolor printers like the Pro9000 better? Yes, provided the range of colors you want to output is outside that of your current printer. With an image with limited colors, the output may look no different at all. So it depends.