Skip to main content
mbrch
Participating Frequently
September 9, 2020
解決済み

100% vs Print Size vs Actual size : something stays unclear

  • September 9, 2020
  • 返信数 3.
  • 41516 ビュー

Dear all, 

When the year starts, I used to teach my students how to properly preview a photoshop document :

- that will be used on screen (View > 100%)

- that will be printed (View > Print size)

I also teach them how to properly set Preferences > Units and Rulers > Screen resolution, to their screen ppi, in order to get accurate display size of their printed document on their own screen.

 

But then I see that function I never noticed before View > Actual size.

My question is simple : What is it for ?

 

To that day, Help webpages, Forums, and online experts chat ("not trained for this")  were not able to answer that question.

 

My question is not just out of curiosity. Because on some of my students Macs, the View>Print size setting does not give accurate display after proper ppi setting in preferences, but View>Actual size does.

Why ?

 

All the best,

M

解決に役立った回答 davescm

A bit of clarity

 

100% is simple - it is 1 screen pixel mapped to 1 image pixel.

 

Print Size - is calculated from the document resolution and the monitor resolution as manually entered in Preferences.

 

Actual Size - is calculated from the document resolution and the monitor resolution as reported by the operating system which in turn gets it from the monitor itself using Extended Display Identification Data (EDID). Whilst this needs no manual entering of values by the user, it only works correctly if the correct value is returned from the monitor and OS. Hence print size is also in the menu for cases where an incorrect value is returned.

 

Dave

返信数 3

davescm
Community Expert
davescmCommunity Expert解決!
Community Expert
May 28, 2021

A bit of clarity

 

100% is simple - it is 1 screen pixel mapped to 1 image pixel.

 

Print Size - is calculated from the document resolution and the monitor resolution as manually entered in Preferences.

 

Actual Size - is calculated from the document resolution and the monitor resolution as reported by the operating system which in turn gets it from the monitor itself using Extended Display Identification Data (EDID). Whilst this needs no manual entering of values by the user, it only works correctly if the correct value is returned from the monitor and OS. Hence print size is also in the menu for cases where an incorrect value is returned.

 

Dave

rob day
Community Expert
Community Expert
May 28, 2021

Hence print size is also in the menu for cases where an incorrect value is returned.

 

Hi Dave, If you have a second monitor with a different res you can get an accurate output view (1" = 1") on both displays by using the res of the monitor that is not the main monitor for the Screen Resolution preference, and using Actual Size to view the image on either display.

davescm
Community Expert
Community Expert
May 28, 2021

Good idea Rob.

Unfortunately here the wrong value is used for my pair of Eizo monitors so only Print Size is accurate.

Dave

gener7
Community Expert
Community Expert
May 28, 2021
Participating Frequently
May 28, 2021

Mine behaves pretty much the same as your Windows machine, except mine seems to be using 108ppi in Actual Size, when the correct value, and what I entered in settings, of 109ppi. So it doesn't appear to be a fixed 100ppi, but rather a variable number that is just off. I added my report to your thread. Not holding my breath for it to be addressed though.

rob day
Community Expert
Community Expert
May 28, 2021

I think your manual measurements might be off, or don’t match the OS’s reported main monitor ppi.

 

Can you run the script I posted above in InDesign?

 

Here it is saved as a .jsx file. If you put it in your InDesign Scripts folder you can run it from the Scripts panel in ID:

 

https://shared-assets.adobe.com/link/17ecd250-0e9c-48fe-6944-8cbccb877f6d

 

https://shared-assets.adobe.com/link/17ecd250-0e9c-48fe-6944-8cbccb877f6d

https://shared-assets.adobe.com/link/17ecd250-0e9c-48fe-6944-8cbccb877f6d

rob day
Community Expert
Community Expert
September 9, 2020

Actual Size considers your main monitor’s resolution and displays actual dimensions—if you show rulers and take a physical measurement 1" will equal 1".

 

Print Size uses your Preferences>Units & Rulers>Screen Resolution setting. If that setting is the same as your main monitor’s resolution, Actual Size and Print Size should be the same.

Participating Frequently
May 28, 2021

Sorry to bump an old thread and thanks for the info. Where does "acutal" size get the monitor resolution and physical size information? I set my Screen Resolution based on dividing my display's horizontal pixels by the measured width and now it is spot on when I use Print Size. Actual Size is a couple percent too small though. Kind of an esoteric question, I guess, since Print Size works perfectly well, but I am curious where PS gets the pixels/inch number from and why it's wrong. Thanks!

TheDigitalDog
Inspiring
May 28, 2021

From the preferences of which you must enter the correct display resolution. 

Measure the width of your display and divide that by the number of pixels its displaying.

For example, on my NEC 3090, the width is 25.25 inches. Its resolution is 2560x1690. 2560/25.25=101.4 PPI.
On my NEC PA271Q, the width is 23.5 inches. Its resolution is 2560x1440. 2560/23.5=109PPI.

Then enter the value into the preferences. Of course, you need to use the Print Size option in the View menu.

 

Author “Color Management for Photographers" & "Photoshop CC Color Management/pluralsight"