Epson L1800

[Ink stained Fingers]

How big i can go ???

If I remember correctly such a question was already discussed quite some time ago , you can print pictures as large as the printer can handle it - e.g. 12x12". How big are the image files you want to print - how many pixels do they have ?

 

[oroblec]

If I remember correctly such a question was already discussed quite some time ago , you can print pictures as large as the printer can handle it - e.g. 12x12". How big are the image files you want to print - how many pixels do they have ?

exactly that is the point i will show later some numbers cause sometimes it confused me i had see low pixels information with good output prints and hight pixels with very poor quality with same settings.

so the real question for me must be, How to calculate print Size. if i tell someone i have a photo 1600 X 1200 with 180 DPi and 640 X 480 with 180 DPi how i know the biggest print i can do with best print quality output.

 

[apetitphoto]

Here's a calculator - one of many that I found with googling "print size calculator"

http://www.scantips.com/calc.html

But the short answer is that most modern printing applications handle that magically. Lightroom, Photoshop, QImage, etc.

 

[oroblec]

Here's a calculator - one of many that I found with googling "print size calculator"

http://www.scantips.com/calc.html

But the short answer is that most modern printing applications handle that magically. Lightroom, Photoshop, QImage, etc.

Woooo Awsome thanks for that apetiphoto, but as you said no matters that numbers new software can change all of this and no matter the quality of the photo you will have a good result caused by the interpolation on new software, so as i don't print in big size my biggest size is 12 X 12 i need to forget to ask my family give me any format and information.

 

[oroblec]

Here's a calculator - one of many that I found with googling "print size calculator"

http://www.scantips.com/calc.html

But the short answer is that most modern printing applications handle that magically. Lightroom, Photoshop, QImage, etc.

Because this weekend i was studied that and the math says if you have 1800 x 1200 photo and you want to know the resolutions at the end. you need to divide the large number with the large number of the print.

Example if you have file size 1800 x 1200 and you want to print in one 4 X 6 you need to do this math. the highest number of the file size 1800 / 6 the highest number of the print i will gives the dpi resolution of 300 DPI this is true or we need to see some other Aspect.

 

[Ink stained Fingers]

o.k., fine, the calculation is correct - 1800/6 =300 , but what did you get there, printed dot density of the printer or pixel density of your image ?
Just take a small scale quarter VGA image as a crop from an old video which just gives 180x120 pixels for the image, and you want to print that on 4x6 inches - that makes 180/6=30 image pixels - ppi - per inch.
And what is the printer doing - it is still placing its dots in a distance of 1/300 inches (it's a Canon in this case) so there are still 300 dots per inch. You deliver a very small picture to the printer and that should be enlarged such that it fits onto the 4x6" paper, so that all these empty spaces between these 30 pixels per inch are filled up with some interim pixels to make up those 300 dpi at the end. That's the interpolation, that's where your print software and the driver start their game, and this type of magnification or reduction is handled by Lightroom and the driver if needed. You just enter the dimensions of your print and the rest is calculated and interpolated pretty much invisible for you. You just get the print coming out of the printer in the right format. And that's the situation where the pixelation may be generated or not - how well these interim pixels are smoothed to avoid a staircase pattern on edges.

 

[Roy Sletcher]

DPReview currently has a thread on this print resolution issue titled "Image resolution/quality overrated for most people?"

You can find it at:
https://www.dpreview.com/forums/post/59772528
You will find an interesting range of opinions, eventually coming back to the definitive, "IT DEPENDS"

rs

 

[apetitphoto]

As rs said, "it depends..."

You are trying, it seems, to equate sensor (pixel) counts to printed dots. They're not equivalent. If, for example, your sensor is 4 pixels by 4 pixels AND you want to print a 12 inch x 12 inch copy of that sensor capture AND your printer prints 300 dots per inch, something would have to convert those 4 pixels into 12x300 dots. Not pixels, dots. So each sensor pixel would become 900 x 900 300dpi dots. ((12 x 300)/4) in each dimension. (This assumes that the printer will do 300x300 dpi. Probably not a good assumption...)

The software is good at this math, and some underlying things, so just tell it what size print you want and let it do its job.

Now, there is another wrinkle that we can ignore for the moment: viewing distance...

 

[apetitphoto]

And another link: https://youtu.be/C2P9iDq-sN0

 

[Ink stained Fingers]

Yes, I think we got all the dots and pixels sorted out .

This assumes that the printer will do 300x300 dpi. Probably not a good assumption...

Why not - a Canon would print with 300 or 600 dpi depending on the driver quality settings, and Epson printers since 15 years do either 360/720dpi or 300/600 dpi with the new precisioncore printheads, so that's the correct numbers to work with. But o.k., that's the hardware driven resolution, you get ink spread etc on the paper reducing the effective and measurable resolution but that would be another subject....