Issue about Pixel

[MahaB82A]

There is a online tutorial which expain about Pixel. I do not agree with a diagram which is given [time 6.06]. Physical size of the image should be same. It is number of pixels made the difference. In otherward more pixel are crammed into same length of 10 cm to get a higher resolutation photo. What do you think?

I attach my view & tutorial diagram.

Image size, Dimension, & Resolution in Adobe Photoshop Ep4/33 [Adobe Photoshop for Beginners]

        

[Bojan Živković]

Not sure what is not clear? Can you further explain what you disagree?

My view is when printed using different resolutions, above diagram (Tutorial diagram) is showing how they will appear on screen at 100% view.

[MahaB82A]

Evethough physical size of the image is 10 x 10 cm why different sizes of three images are shown? 

[Bojan Živković · Accepted solution]

The author wants to show different pixel dimensions on the screen. Images on the screen do not have the same dimensions as when they are printed on paper. When printed, images will have the same physical size, but this is not the case on the screen. It would be incorrect if the images were printed and presented as smaller or larger in this case.

[MahaB82A]

Thanks for the explanation.

[jane-e]

Some of the confusion might be that the author gives the dimensions in pixels, then uses a "d" instead of a "p" represent the "p" in "pixels". The acronym for pixels per inch is ppi, not dpi.

[MahaB82A]

Thanks. I notice this as well. Where is it used DPI [dot per inch]

[jane-e]

Hi @MahaB82A 

Dots per inch (dpi) refers to ink on paper and is controlled by the printing device.

Jane

[MahaB82A]

Thanks.

[jane-e]

You're welcome @MahaB82A 😊

Jane

[MahaB82A]

Suppose a printer resolution is 300dpi. How to determine what should be the ppi to get 300 dpi print? 

[Bojan Živković · Accepted solution]

Basically thats the same thing. PPI will be converted to DPI without any lose. Pixel will become dot silently.

[Creamer Training · Accepted solution]

Don't worry about printer resolution. Laser printers go anywhere from 600-2400 (or higher). 

• For compact PDFs, I use 150-225 ppi. This will give enough quality for a desktop printer but keep the file size down.
• For commercial offset printing, I use 225-300 ppi.

Note overlap of 225--I use 225 for layouts that could go either way.

Web graphics have no ppi (sometimes called dpi)--they are strictly X-pixels by Y-pixels. PPI is meaningless.

Here is an example of the different terms:

I've attached an old PDF too, while dated the info is generally still accurate.