Document Setup & *.ai files

[JDW]

I am opening existing *.ai files in Affinity Designer and conducting compatibility tests.  In AD, if I click the "Document Setup..." button shown in the upper left corner of the Toolbar, it shows me "DPI: 300" in the Dimensions tab.  This is confusing me.  Say I have a linked EPS file that is 350dpi in that document.  Will it be scaled down to 300dpi??  Or does that simply indicate that when you Rasterize something it will be 300dpi?  If the latter is true, why not call it "Raster DPI" instead of just DPI?

[JDW]

Another thing that confuses me on this topic is Resolution Independence.  

 

For example, in my CMYK Illustrator documents, I can zoom in on my vector art and see everything look perfectly smooth (no pixelation) even at 6400% zoom.  But in Affinity Designer, I see pixels at 200% zoom on my vector art.

 

I would expect to see pixelation on my raster graphics as I zoom in on them but not on my vectors.  

 

That is what has me confused about that "DPI: 300" setting in the Dimensions tab of "Document Setup..."  Why does Affinity Designer need it when Illustrator does not?

 

UPDATE:  Okay... Stupid me...  I now see View > View Mode > Vector.  In that view mode all my vectors are smooth.  Got it.  Even so, I still want to know more about that "DPI: 300" setting and how it will affect my embedded, rasterized graphics (if at all).

[Dave Harris]

Mostly the DPI means the resolution at which things will be rasterised. For .ai and .pdf files, the initial value is mostly a guess based on the placed bitmaps in the file. It also affects the native size for zoom options, Pixel View Mode, and for bitmap exports.

[JDW]

Mostly the DPI means the resolution at which things will be rasterised. For .ai and .pdf files, the initial value is mostly a guess based on the placed bitmaps in the file. It also affects the native size for zoom options, Pixel View Mode, and for bitmap exports.

Right... "rasters and bitmap exports."

Which begs the question, how will already rasterized bitmaps be treated?

 

Let's say I have an AI file with linked EPS graphics which are all 350dpi. So as to open it in AD I resave it in Illustrator with PDF content enabled (which many Illustrator users don't do by default in order to keep AI file sizes small), then open that AI file in AD using the default 300dpi setting. AD will embed all the linked EPS graphics at their native 350dpi resolution but export them at 300dpi? Is that how it works?

[Dave Harris]

EPS can contain vectors, too, which AD will keep as vectors. Any bitmaps, from any source, will be embedded in AD at their native resolution. When export to a vector format like PDF, EPS or SVG, you can control whether you want them to be output at their native resolution, or whether to downsample them. If you are using File > Export, click the More button to see all the options available; or scroll the panel in the Export persona. By default we also offer three presets: "Export" will not downsample, "Print" will downsample to 300dpi, and "Web" will downsample to 72dpi. You can create your own export presets if these aren't suitable.

 

If the bitmaps are not downsampled or rasterised, we endeavour to output their original compressed data if it's available, to avoid quality losses from uncompressing and recompressing. You can also control whether JPEG (lossy) compression is used at all.

 

Basically, we try to do the best thing.