300 DPI VS 360 DPI - When to use with what printer?

The 1440 rothers refers to is simply 360ppi multiplied by the 4 different ink carts. . My R2880 uses 8 carts, so 360 x 8 = 2880. Magic init?

I've also tried sending whatever ppi an image ends up as well as exactly 360. As long as it is above 180ppi natively, I am unable to see any difference. The printer driver seems to do a pretty good job of resampling.

Lowner wrote in post #10677107
The 1440 rothers refers to is simply 360ppi multiplied by the 4 different ink carts. . My R2880 uses 8 carts, so 360 x 8 = 2880. Magic init?

I don't think so. I believe that it is the product of the native resolution of the print head times the number of passes the print head makes over a point.

For instance, your R2880 can also print at lower resolutions, i.e. it makes less passes per point. It does not stop using 4 of the carts to print at 1440 ppi.

Poe wrote in post #10673602
I'd like to make 18" x 12" prints from my 7D image files.

Would it be better to resample the 7D images to 5400 x 3600 and 300 PPI in software such as PS which would let the printer have a native 300 PPI file for the print or let the printer do the resampling of the 5184 x 3456 image to get to 300 PPI for a 12" x 18" print?

It depends on how much of a control freak you are. I am really bad, it's the primary reason why I have an ink guzzling printer. For a long time I didn't trust LR's output sharpening, for which there is no preview and no more control than Low, Medium, High. I had my own elaborate high-pass routine that was evolved over the years. The same applied, of course, to leaving it to the printer, which does, I assume some sharpening after the resample, but who knows what or how. Today I start each printing session with a large dose of Prozac, which has enabled me to live happily with printing directly from Lightroom.

Mark,

Epson use that exact explanation themselves. You are telling us that Epson are wrong? I think not, they make the things, they should know.

Kolor-Pikker wrote in post #10671722
Technically speaking, Epson printers want 720ppi input, but 360ppi is the closest realistic alternative. If you print via Qimage, it will automatically use it's own upsize & sharpening routine to send a 720ppi file to an Epson printer.

As a blanket statement, not accurate. Depends upon the printer model.

From Epson support:

Epson large format printers use 360 as input, it's the desktop models that rasterize at 720. My 3800 has a native res of 360, but can also utilize 720 with user selected driver settings.

Lowner wrote in post #10677246
Mark,

Epson use that exact explanation themselves. You are telling us that Epson are wrong? I think not, they make the things, they should know.

I have never seen nor heard of that before & I believe it to be purely marketing hype.

As an example, have a look at some of the smaller printers, with 4 colors/cartridges and compare their stated max. resolutions.

Also, please explain how you can use just some colors (not the full compliment) with differing papers having the max. resolutions. i.e. with some glossy papers using the full complement & 8 bi-directional passes while some matt papers utilize 6 colors with the same number of passes.

Mark,

Only one direction is an accurate representation of ppi/dpi, the other can be manipulated by, as you rightly said, smaller advances and more passes. And yes, marketing hype has a lot to do with these claims and it confuses a lot of buyers.

The 8 times 360 I quoted for the R2880 is its "natural" maximum. There is a so called 720 or even 1440 option, but I've tried them and can see no improvement over the normal 360. These can only be achieved artificially.