Printer resolution question

[madhatter]

Hi

Been taking pictures for a while now, im no expert but a keen ameteur. Using a 2mega pixel finepix, about to go for my first digital SLR.

Anyway, to my question. Ive been doing the maths, and a "2 mega pixel 1600x1200 image will print a 240dpi picture at 6.5" x 5" (approx).

I like to print my images on A4 and to be honest my 2mega pixel images are coming out pretty good. Again doing the maths this works out at about 145dpi, way below 240dpi but honestly, they are not bad prints.

So, my Epson R200 has a quoted resolution of 5760 x 1440. This is what I dont understand. It has 6 ink pots and 1440/6 = 240, hence it is capable of 240dpi. (Been to all the web sites, analy trudged through all the info and I think Ive got my maths right).

So, whats the relevence of the 5760 part ? Surely 240dpi means exactly that, 240 dots per square inch. Or is it 240 dots per inch per line, and 5760 lines.

Im a little confused.

Help appreciated.

Chris.

 

[terri]

Hi Chris, welcome to TPF!

You posted this in the Darkroom forum, so I'm moving it to the General Q&A where it will get some more views and, hopefully, some answers for you.

 

[benhasajeep]

First the printer can put any number of different color dots onto a single point (to make various colors, in your case 6 basic colors to make any number of other colors). So you do not divide by 6.

Basically if your printer can produce 1440 dpi. It makes a single line that uses 1440 dots to make a 1" wide line (if you are at 1440 dpi). That is smaller than your eye can see (single dot that is). Most people say prints at 300dpi is normal if there is a normal. Printing at a smaller dpi is ok deppending on how low you go. Many feel any more than 300dpi is wasting ink unless you have a pic with some really fine detail.

Your printers resolution is more than enough for quality prints!

Your printer can put down a maximum of 1440 dpi (across, and up/down). So whats the 5760 for then? The printer can make 4 passes per line. Which equals 5760 dots per inch. Some printers will actually shift the paper just a fraction so the dots are slightly offset giving the higher resolution.