Incorrect size of objects on the Mac Retina 5K screen

[GRAFKOM]

I bought a 27-inch Retina 5K iMac computer macOS 10.15.4 especially for Affinity programs and it turns out that I have a problem with the actual size on the screen. Although, for example, the size of the rectangle is 10x10 cm in the design, with a 100% preview, the size of this rectangle on the screen is 88x88mm.
Is there any possibility to set the correct screen size in Affinity?
With Windows on the 23-inch screen there was no problem, the size of the rectangle on the screen at 100% preview was actually 10 x 10 cm (measured with a simple ruler).

I need the actual size on the screen when designing, for example, business cards and leaflets to check the correct size of the project, without the need for control printing.

[walt.farrell]

I think that perhaps you should be using View > Zoom > Actual Size, not 100%.

Shortcut is Cmd+8 (Ctrl+8 on Windows).

[GRAFKOM]

The real size is 100%.
I have a second 23-inch monitor connected to the 27-inch iMac. On a 27-inch screen, the actual size agrees, i.e. a 10x10 cm rectangle in the design has a 10x10cm screen with a 100% visibility setting, while when displaying this design on a second monitor screen 23 inches, with a 100% display setting the rectangle size on the screen is 11x11cm .
What can be done to ensure that the 100% real size is displayed correctly on both monitors?

 

[Old Bruce]

A word of advice (feel free to ignore it, after all it is unasked for)

Set your document units to Centimetres or Millimetres and do not measure the screen. Measuring the screen will make you crazy, trust that the computer will do all the maths for displaying the things at the right size, the size you want them to be when printed out. Check the Transform panel for sizes of objects, it is far more accurate than any hand held ruler will ever be.

[GRAFKOM]

I do not mean that I do not believe that the 10 x10 cm computer will convert correctly.
During my normal work in the company, where I design business cards, letterheads and other advertising-related things, I can already see the actual size during design, e.g. business cards and font sizes on the screen at 100% visibility setting without constantly printing the card to check these sizes .
I am working now on the iMac 27 inches and here it is correct, but if I move the program window to the monitor connected 23 inches, the size of the business card on the screen increases. As I know that normally the design has not changed, only the display on the screen changes, so setting the display on this screen 23 inches to 100% no longer shows the actual size, so if, for example, I would like to show my client on the screen without printing on the card of this business card, the real size would be larger.

[walt.farrell]

34 minutes ago, GRAFKOM said:

The real size is 100%.

No. Using Actual Size gives you the real size on screen, for documents sized in units other than pixels.

With 100%, 1 pixel of your document occupies 1 pixel of your display screen.

Therefore, if you have a 10cm wide document, at 300dpi (ppi), then your 10cm document has 3000 pixels. If your display happens to show 300px per cm, it will appear 10cm wide on the display. But at any other display pixel density it will not be 10cm wide.

If you haven't tried View > Zoom > Actual Size please do try it, and measure it.

[Old Bruce]

The problem is probably that the two monitors have different pixel sizes. There is no easy fix for this. What is the brand of monitor that you are using as a second screen?

[GRAFKOM]

Samsung 23cale FULL HD

[GRAFKOM]

The most interesting thing is that the Project with this 10x10cm square running in Publisher Win in Parallels Desktop on this 23 inch screen displays the screen size at 100%.
I have bought Affinity packages for MAC and WINDOWS.

[Old Bruce]

Quick bit of math gives me a 1.175 magnification ratio for the Samsung. That looks about right.

It has been years (decades?) since I last ran multiple monitors, quit using them because of other problems as well as this one.

You may not be able to change the display ratio but I would suggest going to the apple forums https://support.apple.com/ this gives the English version on my machine, click on Mac and then type your question into the search field.

This stuff is beyond my limited capabilities to help with.

[GRAFKOM]

22 minutes ago, walt.farrell said:

If you haven't tried View > Zoom > Actual Size please do try it, and measure it.

On the iMac monitor 27 inches displays correctly when setting the current size, while on the screen 23 inches when setting the current size - the size on the screen is incorrect (too large by 1cm)

[Old Bruce]

If you are using the second monitor to show to clients you could just use 85% with the zoom tool.

[lepr]

On 5/8/2020 at 4:14 PM, walt.farrell said:

No. Using Actual Size gives you the real size on screen, for documents sized in units other than pixels.

With 100%, 1 pixel of your document occupies 1 pixel of your display screen.

Therefore, if you have a 10cm wide document, at 300dpi (ppi), then your 10cm document has 3000 pixels. If your display happens to show 300px per cm, it will appear 10cm wide on the display. But at any other display pixel density it will not be 10cm wide.

If you haven't tried View > Zoom > Actual Size please do try it, and measure it.

In Designer and Publisher on macOS, when document units is a physical unit such as cm or inches, 100% zoom is the same as Actual Size zoom and both should result in the object on the screen being real world size. It so happens that the displayed size is only about 97% 98.8% of real world size on my iMac Retina 5K screen.

Edited May 10, 2020 by anon2
correction

[wonderings]

I have a 27" iMac as well. Never measured the onscreen sizes when viewing "actual size" Just assumed it was exactly that. I made a 5" square box in Designer, Illustrator and Indesign and when measured on the screen they were all about .125" smaller then 5". Not a big deal for me, but not "actual size" as the name suggests. I wonder if this is a Mac OS thing if Windows is hitting the size right now. Certainly does not seem isolated to Affinity software. 

[lepr]

On 5/8/2020 at 4:43 PM, wonderings said:

I have a 27" iMac as well. Never measured the onscreen sizes when viewing "actual size" Just assumed it was exactly that. I made a 5" square box in Designer, Illustrator and Indesign and when measured on the screen they were all about .125" smaller then 5". Not a big deal for me, but not "actual size" as the name suggests. I wonder if this is a Mac OS thing if Windows is hitting the size right now. Certainly does not seem isolated to Affinity software. 

That's the same sized a similar error as I get on a 27" iMac. It could be that the OS is returning an incorrect pixel density for the screen when an app requests that data, and then the app scales its view based on the incorrect data.

Edited May 10, 2020 by anon2
correction

[thomaso]

On 5/7/2020 at 12:22 AM, GRAFKOM said:

I need the actual size on the screen when designing,(...) without the need for control printing.

Indeed various hardware can be disturbing in their different pixel resolution, and pixel size as Bruce mentioned. I know your desire from many years doing layouts for exhibition walls. Since those were done in scale 1:10 it was important to check the real text size occasionally. That time I still was using InDesign with a second monitor. The only way to get it in real size was to measure once the real ratio with a physical ruler (as you did) and then calculate the according zoom level. Then I used a script in ID to set it to this level with 1 click.

In Affinity nowadays I have to set the zoom level manually to 85% every time I want to see true 100% on my external monitor. In Affinity the customizable "Viewpoints" (History Panel > Advanced) do work to maintain the zoom level but – quite unfortunately – also are limited to a specific page or page detail.

Have you tried the various options in the monitor system preferences? There at least you have a few options related to size/resolution:

https://support.apple.com/en-us/HT20247

[GRAFKOM]

As I wrote earlier.
on this screen, the 23-inch project open in Publisher MAC version is displayed as too large, while when you open this project in Publisher windows version in Parallels Desktop, the project is displayed correctly. (actual size).
Before publishing this question on the forum, I did probably a thousand attempts at various screen settings, and unfortunately I could not do what I wanted.

[R C-R]

20 hours ago, GRAFKOM said:

The real size is 100%.

As I understand it, Actual Size (theoretically) sets the document display size to the print size, taking into account the document DPI, so since the DPI could be anything, it will not typically be the same as 100% display size.

As for the 'Mac thing,' my non-retina iMac typically displays "Actual Size" at about 0.97 of the true print size.

Edited May 9, 2020 by R C-R

[lepr]

23 hours ago, R C-R said:

As I understand it, Actual Size [...] will not typically be the same as 100% display size.

Once again, I'm sorry to have to disagree with you.

As stated in one of my earlier posts in this very thread: 

"In Designer and Publisher on macOS, when document units is a physical unit such as cm or inches, 100% zoom is the same as Actual Size zoom [...]"

[deleted]

Edited May 10, 2020 by anon2

[v_kyr]

In order to get on every screen visually then one and the same 10 x 10 cm shown by your measuring, use ... 😀😉

[R C-R]

54 minutes ago, anon2 said:

Once again, I'm sorry to have to disagree with you.

As stated in one of my earlier posts in this very thread: 

"In Designer and Publisher on macOS, when document units is a physical unit such as cm or inches, 100% zoom is the same as Actual Size zoom [...]"

Yes, you are correct about that, but the weird thing about it (to me anyway) is it is not true for Affinity Photo or for Publisher's Photo Persona, so while "typically" was a poor choice, it is not entirely wrong.

0.97% was an edit error, now fixed.

[lepr]

1 minute ago, R C-R said:

the weird thing about it (to me anyway) is it is not true for Affinity Photo or for Publisher's Photo Persona

My guess is that the developers reckoned people are most likely to want 100% zoom to relate to pixels in Photo and Publisher's Photo Persona, and to want 100% zoom to relate to physical units elsewhere.

[thomaso]

18 minutes ago, anon2 said:

My guess is that the developers reckoned people are most likely to want 100% zoom to relate to pixels in Photo and Publisher's Photo Persona, and to want 100% zoom to relate to physical units elsewhere.

But what are these different calculations based on?

For instance on my external 24" the different zoom levels for 100% real output size are 85% (mm) versus 62% (pixel). So what parameters are used for the calculation, since the physical pixel resolution of the hardware of course is the same for both units/views?

[walt.farrell]

2 hours ago, anon2 said:

Once again, I'm sorry to have to disagree with you.

As stated in one of my earlier posts in this very thread: 

"In Designer and Publisher on macOS, when document units is a physical unit such as cm or inches, 100% zoom is the same as Actual Size zoom [...]"

What does the Affinity Help on Mac have to say about that? For Windows it clearly says that a zoom of 100% displays 1px of image using 1px of screen. That can't possibly be the same as Actual Size unless the document DPI matches the screen resolution.

If the Help on Mac says the same, then either the Help is wrong, the program is displaying incorrectly, or your measurements are wrong (Or, something I haven't thought of is happening.)

[R C-R]

40 minutes ago, anon2 said:

My guess is that the developers reckoned people are most likely to want 100% zoom to relate to pixels in Photo and Publisher's Photo Persona, and to want 100% zoom to relate to physical units elsewhere.

Maybe, but it seems to me that the only logical way for this to work would be that "Actual Size" in every context always means display at physical print size, since printed output is the only thing that has any invariant tangible physical dimensions. I also find it bizarre that the view size options for physical document units are not all always the same as for pixel units, but maybe that is just me.

31 minutes ago, thomaso said:

But what are these different calculations based on?

The staff have tried to explain this from time to time, but I get the feeling that even they are not quite sure how to explain it.

The "Mac OS thing" is yet another head scratcher for me. For images files, the Mac Preview app offers 2 alternatives for 100% scale, "1 image pixel equals 1 screen pixel" & "Size on screen equals size on printout." The latter option does not reduce the display size -- a 1 inch square png file is exactly 1 inch square on my iMac's screen at the "actual size" zoom level -- & to the best of my ability to measure it, the former seems consistent with the image's pixel dimensions & my screen's PPI.

This implies to me that the OS is fully capable of calculating screen pixel density so there must be something wrong with how the Affinity apps use it.