SureColor P95xx/75xx, indeed 300/600 PPI device, but Head-Alignment not perfect!
Triggered by Jim Kasson's remark in earlier post, i did the following test to determine the PPI resolution of the SCP95xx printer.
I use W10 and Lightroom Classic, and the 600PPI res-test file of Baert van der Wolf.
I found interesting aliasing artefacts, basically proofing the printer is a 300/600PPI device (translated to 1440/2880 DPI on the print).
But also that the Head-alingment needs some improvement.
In Lightroom print module i placed on an A4 the res-test, with image dimensions adjusted to get different PPI:
567PPI
598PPI
600PPI
602PPI
615PPI
The PPI setting in the print job is set accordingly, and no output sharpening applied. In this way Lightroom creates a print file wih that PPI resolution. To double-check i also did print to file, with the same PPI settings, to be sure that the print output file does not introduce aliasing artefacts.
In the SCP9500 printer driver (v6.72) the print quality setting is set to level=5, Fine Details=ON, the paper edge quality set to Standard, the res-test image centered on the page via the driver, to stay away fromm any paper edge print quality issues, typical for the double-head concept.
As media type i used Epson Premium Glossy 250gsm. In the media settings is the button "custom Settings" that allows you to save your media settings. As i am not using a custom media, this functions ok.
For each PPI value i saved the whole setting in a printjob in Lightroom, and double checked that the settings in the driver stayed as set.
Note that the SCP95/75 driver up to 6.72 is notoriously poor in that respect.
I did a feed-alignment and then a head-alignment, then I issued the print jobs one by one. Prints are on a glossy PE-paper.
Then i found a way to take a picture of the print without introducing aliasing artefacts, by using my 2019 iPAD and with a distance of 7cm it still focused well, and did not introduce visible artefacts. So the artefacts you see in the images are as they are in the print.
The pictures show the center of the "siemens" star, including the 300PPI and 600PPI rings. One picture shows the bottom-left (linksonder) part of the res-test image, there test "4" shows black lines in 4 different directions, and if perfect each quadrant should give an equal greyish impression when viewed from a distance.
Conclusion:
Send files with 300PPI or 600PPI to the printer, else you are in for some negative surprises.
Head-alignment is techniclly speaking close to perfect, BUT, NOT SO FOR THE BLACK INK. Vertical lines get always printed a that fatter than horizontal lines, also some false colors are visible.
The number of attachment is limited to 4, so:
SCP9500-GlossyPaper-598PPI-600PPI-1.jpg :
some horizontal and vertical "vague banding" across the 300PPI ring as well as stronger aliasing artefacts.
SCP9500-GlossyPaper-600PPI-600PPI-1.jpg :
very modest aliasing artefacts. When shown on my EIZO CG248-4K zoomed in 100% is see the same artefacts.
You also see, on the real print a bit better, that the printer resolution , its modulation transfer, sort of is 0 at the 600 PPI ring.
SCP9500-GlossyPaper-615PPI-600PPI-1.jpg :
again several horizontal and vertical "vague banding" across the 300PPI ring as well as stronger aliasing artefacts.
SCP9500-GlossyPaper-600PPI-600PPI-Linksonder-1.jpg:
diagonal lines are almost equal, the vertical lines are fatter than the horizontal lines, and some false color is visible in the horizontal lines.
Note that the aliasing artefacts are quite symmetrical in the "Siemens" star (is composed out of a sinus variation and not just black lines),
but in the center rings one gets a sort of oval impression (more black ink), this is the effect of the not perfect alignment of the Black Ink.
Personally i use primarely Lightroom Classic for printing, and allways have the print output PPI setting set to the printer resolution, 300/600 or 360/720 depening on the printer used. I also sometimes use other pinting applications, in these too i set the output PPI accordingly.
So for me i accept the fact that the SCP95/75 is a 300/600PPI printer.
The only issue left is the Head Alignment, which is not good for the BLACK INK.