Can you determine the zoom factor from the paper size?

[zBernie]

Can the equivalent zoom factor be determined by the paper size?  For example, if I print something at 8.5 x 11 what zoom size does that correspond to in Affinity Photo?  And the same question for 11 x 17, what equivalent zoom in AP would that be?

I'd like to get an idea of what the printed composition would look like printed on various paper sizes by zooming the picture to 30%, or 40%, etc., and viewing it prior to printing.

-Thanks

[carl123]

I think View > Zoom > Actual Size may do what you want

[thomaso]

It may vary on a different / additional monitor. Recipe: Hold a sheet of the desired size (or any flat object of known size) on the monitor and adjust the zoom level to fit a layout object of the same size to the physical object. Then you can use the Navigator panel and save the resulting zoom level as a viewpoint for easier access to specific views.

https://affinity.help/photo/English.lproj/index.html?page=pages/Panels/navigatorPanel.html?title=Navigator panel

[zBernie]

7 hours ago, thomaso said:

It may vary on a different / additional monitor. Recipe: Hold a sheet of the desired size (or any flat object of known size) on the monitor and adjust the zoom level to fit a layout object of the same size to the physical object. Then you can use the Navigator panel and save the resulting zoom level as a viewpoint for easier access to specific views.

https://affinity.help/photo/English.lproj/index.html?page=pages/Panels/navigatorPanel.html?title=Navigator panel

Thanks, that is essentially what I've been doing now.  I thought there might be a mathematical way to determine which zoom size corresponds to which paper size.

[zBernie]

8 hours ago, carl123 said:

I think View > Zoom > Actual Size may do what you want

No, that's not what I'm looking for.  See my reply to thomaso.

[thomaso]

1 hour ago, zBernie said:

I thought there might be a mathematical way to determine which zoom size corresponds to which paper size.

This exists, but it appears more cumbersome. You have to know the hardware pixel size of the corresponding monitor next to its currently set resolution ('density') to mathematically calculate the 100% zoom value. I guess Affinity might be unable to calculate this value correctly if multiple monitors are connected and/or the screen resolution differs from the 'natural' default resolution of its monitor hardware and the operating system does not pass this information correctly to Affinity. – Therefore @carl123's hint does indeed work in most setups.

[R C-R]

13 hours ago, zBernie said:

Can the equivalent zoom factor be determined by the paper size?  For example, if I print something at 8.5 x 11 what zoom size does that correspond to in Affinity Photo?

How are you setting paper size? In Affinity on my Mac, I set the paper size at print time via the Print window's Paper Size popup menu. I can also choose from any arbitrary scale factor, 'fit to printable,' or 'shrink to printable.'

All of these things depend on the selected printer & what it supports, so I am not sure if there is any way to determine a 'universal' equivalent zoom factor.

[kenmcd]

13 hours ago, zBernie said:

I'd like to get an idea of what the printed composition would look like printed on various paper sizes by zooming the picture to 30%, or 40%, etc., and viewing it prior to printing.

4 hours ago, zBernie said:

I thought there might be a mathematical way to determine which zoom size corresponds to which paper size.

It appears you want to see an actual size preview for different assumed paper sizes - on screen.

Assuming you start with a 8.5x11 document ... when you select a zoom of Actual Size you will see an actual 8.5x11 image on your screen. At upper left by the file name you will see the zoom percentage used to display this in the correct size (this is going to depend your screen resolution PPI, OS zoom settings, document DPI, etc.).

On my screen for Actual Size zoom I see 88.8% to show me a full 8.5x11 doc at actual size.
So to change this to show what this would look like at 11x17 I need to increase the width.
Width of 8.5 increased to 11 is a change of 129.41%.

So 88.8% x 129.41% = 114.92%
Put that into the Navigator panel and you will have an "actual size" 11 x ~14.2 on screen.

Remember that 88.8% is based on my screen resolution (133 PPI), doc DPI (300), etc.
Yours will be different.