Export in AD not respecting set DPI

[pingram]

Having issues with export on AD for iPad.

I created a 2000px x 4000px document @ 72dpi.

When I export using defaults, PDF for digital-small, the file size is nice at only 72kb but the rendered dimension in Mac Preview is twice the size expected.  When viewed at "original" size, it fills my entire 4k which is near 4000px, double the width of the document I created and expected upon import.

I've tried disabling the "use document resolution" and no matter what DPI I choose, 72, 150, 300...the exported file is always the same dimensions and exact same file size .

1. Why is the DPI settings being ignored when I untick the doc resolution and set it manually to a value?

2. How can I view the current open document's DPI?  (I tried the Resize tool as mentioned in another thread, but DPI is not shown anywhere)

[Dan C]

Hi @pingram3541,

Sorry to hear you're having trouble!

11 hours ago, pingram3541 said:

I've tried disabling the "use document resolution" and no matter what DPI I choose, 72, 150, 300...the exported file is always the same dimensions and exact same file size .

1. Why is the DPI settings being ignored when I untick the doc resolution and set it manually to a value?

Could you please provide a screenshot of your PDF export settings in the Affinity app for me?

11 hours ago, pingram3541 said:

but the rendered dimension in Mac Preview is twice the size expected

AFAIK, Mac preview may not be the best app for this, do you have any other PDF readers that you can open this file in to check it's dimensions/DPI?

11 hours ago, pingram3541 said:

2. How can I view the current open document's DPI?  (I tried the Resize tool as mentioned in another thread, but DPI is not shown anywhere)

The Document > Resize option is one way of finding the DPI, please note you'll need to press the Arrow on the right hand side of the context toolbar to change the context view to the next set of options, as shown below - 

 

I hope this helps!

[pingram]

That last one was definitely helpful seeing the video but I still swear I had looked for an indication on either side to either scroll or "see more" but I saw nothing but sure enough it's there after seeing this post.  *magic* haha. 

As for the pdf, when I open it up in AD for Mac, it is half my 4k screen @ 100% and consumes exactly 2000 pixels in width, as the document was saved and as expected.  In preview, when viewed at 100% it scales to my entire screen and is near 4k pixels (100% document size not window width).  I think it must be missing some meta, embed or similar because I can open other pdfs not created in AD for iPad and they open both in Mac Preview AND AD for Mac @ half my 4k (2000px) when viewed at 100%.

Here is the screenshot of the pdf settings, note that when choosing the Preset "PDF (digital - small size)" the preset shows "Custom" but nothing was modified after choosing that preset.  I also verified the document dpi is 72.  Even when disabling "use document resolution" and choosing 300 DPI, there is no difference in it's resulting file size nor how Preview displays it @ 4000 pixels.  The Preview "file info" shows the exact same dimensions in inches.

I doubt my clients will be viewing on such large displays but I needed to make sure it scaled down and didn't open by default having essentially a double zoom factor.  I haven't tested other pdf viewers yet, however, exporting to png and then saving that as a pdf from AD for Mac seems to fix this little quirk.

[Dan C]

Thanks for letting me know and many thanks for the screenshot provided.

I'd like to request a copy of both the Affinity document, and the PDF you have already exported.

Can you please upload these two documents to the below link, then once completed please reply here to let me know:

https://www.dropbox.com/request/X3vqmuY9VmB6blmLNU5k

Many thanks in advance

[pingram]

I apologize.  I think I know what's throwing me off.  In the world of pdf, the size is based on print dimensions in/cm and dpi and not pixels like raster images like png, jpeg, gif, bmp?

For example, I save a 2000px x 4000px document as a pdf and it results in a document that is defined by inches (27.7~in x 55.5~in) and when viewed on a 4k it is near the entire 3840px width of the screen when viewed at 100% or Actual Size (there is no "pixel" view).

In Affinity Designer for desktop, when viewing the 2000px x 4000px document at 100% in the Navigator, it only takes up half the screen i.e. consuming exactly 2000 actual pixels.  I then discovered, there is a "pixel view" (default) but there is also an "actual view" in AD and when choosing that, it displays in what would be inches using my entire 4k screen just like the exported pdfs.

If I export PNG and open it in Preview, it takes up exactly 2000 pixels of my screen.  This was the desired result for the PDF version but nothing I try in the PDF export (setting DPI to anything) changes the output file, not even the file size is different.  It's as if DPI doesn't matter when it comes to exporting pdf.

I have come to terms there is no way to force a pdf document to open by default based on the document's actual pixel dimensions based on the monitor's DPI (72 which is also the documents DPI).

Checking again, there was no difference between exporting pdf on Mac or iPad except the embedded png method resulted in an increased file size but both open in Mac Preview using twice the pixel density of the original document (consuming roughly 4000 pixels across my screen) at 100%/Actual Size instead of 2000 pixels and no matter what DPI I set, I cannot get it to export a pdf in which opening and viewing @ 100% is the REAL 2000 pixels on my screen.

I just sent my client a png.

[Dan C]

11 hours ago, pingram said:

In the world of pdf, the size is based on print dimensions in/cm and dpi and not pixels like raster images

PDF's can be defined by both pixel sizes and physical dimensions with DPI.  I believe the issue may be due to using Preview to open your PDFs, as this is not the best application for checking this.

For this reason, I wanted to double check both your Affinity document and the exported PDF, to ensure that nothing was wrong with the settings you have used.

If you'd like, I'm still more than happy to double check this, if you can upload these documents to the previously provided link.

Unfortunately without these documents I am simply guessing based on your description and I would rather be more exact - many thanks!

[pingram]

Hi Dan. I uploaded 3 documents yesterday to the dropbox link you provided when I replied previously.  One being the original pdf export from AD for iPad, the other AD for desktop and the png that was used for the AD for desktop version pdf.  Let me know if I need to re-upload them.

[Dan C]

Many thanks for the 2 PDFs provided - I have opened both of these in Acrobat PDF reader and Affinity Designer. In both apps the reported PDF size is 2000px x 4200px or 27.778" x 58.333" - which as far as I understand is the size we're expecting to see.

I recommend using a different PDF viewer in the future to double check these things, as Mac Preview is good for a 'quick glance' at a file, but for any more in-depth work or Preflight functionality (such as checking the size) I would say that Preview is not the right app for this.

I hope this helps

[pingram]

Yeah I'm sorry I think I might have wasted your time mentioning how Preview kind of does it's own thing regarding the default viewable scale.  I must have some warped misunderstanding of DPI and how it impacts a document size (viewable scale and size on disk).

When I export that 2000x4200 design using either AD Mac or AD iPad, changing the DPI doesn't have any impact on the output file. 

For example, I did 3 tests on each version of AD (6 total exports).  I used the default pdf settings except I chose to override the document's set DPI (72) and for one chose 300 and the other chose 96.  The files, besides the names I gave, them were identical to the 72dpi export pdf files. 6 files, 6 copies.

- File AD Mac 72
- File AD Mac 96
- File AD Mac 300
- File AD iPad 72
- File AD iPad 96
- File AD iPad 300

They are all byte for byte the same file and open in Preview full screen @ 100% and open half screen on PDF Professional and AD Mac (expected size) when viewed at 100%, when I choose "actual view" in AD Mac however, it scales to 169% which is I think what Preview is doing by default.  Yes, Preview is doing it's own odd thing with scale but it's beside the point, my curiosity is the 6 identical file outputs.  Shouldn't I have 3 sets, where within each set, 2 of the files are identical except for name (72, 72), (96, 96), (300, 300)?  Thx

[Dan C]

No problem at all, happy to help!

13 hours ago, pingram said:

When I export that 2000x4200 design using either AD Mac or AD iPad, changing the DPI doesn't have any impact on the output file. 

Setting the DPI value will only change the file when objects are being rasterised (or printed, which also requires rasterisation).

Changing the DPI when exporting for a PDF for a file using 'Pixels' as the Units will not affect the 'Media Box' size of the PDF, and therefore the file itself will be almost identical regardless of the DPI set here.

If you want the DPI value to change the physical size of the document, you will need to use a different unit option, such as MM or Inches.

I hope this clears things up 

[pingram]

Thanks Dan yes it does, it all clicked when you mentioned raster. 😃