How to define different vertical and horizontal resolution?

[HenryFernandez]

Is it possible to define different ppi values for the vertical and the horizontal dimension of a document so that an A3 size contains 1920x1080 pixels?

[Alexandre Becquet]

Hello, the document as a value for the resolution/ Different if it's for print, web or video. You can't defineresolution for horizontal or vertical but only the size.

But you can import different assets with different PPI values. 

[Luke Jennings3]

Can you provide some additional information about what you are trying to do? You can open an A3 PDF in Photoshop and export to an image format at your desired pixel size, but it will be distorted and will no longer fit an A3 page. (File> Export> Save for web [Legacy]). You can scale an image placed in InDesign, using separate values for the height and width (click the chain icon to allow distortion) and export to a PDF (without downsampling), which will produce a PDF containing an image with non-matching resolutions, as indicated in Acrobat using the Output Preview tool Object Inspector.

[HenryFernandez]

Thank you for your reply.

I've been asked to produce a document of 1920x1080 pixels which will be printed in A3 paper size. The document should not rescale nor deform when printed. The only way to see this possible is with having rectangular pixels with dimensions 219x278 micrometers. Maybe I'm overthinking this... but if it's possible to tell the printer that pixels are not squares that woul do. Maybe it's not possible and I should just rescale the document in an A3 paper size.

[John Mensinger]

It's not really clear what your objectives are. You're mixing the concepts of page size (physical paper dimensions) and "pixel dimensions," normally an on-screen image size reference. In print applications, InDesign has no blanket resolution setting at the document level. Each element you put on an InDesign page has its own attributes in that regard; you may have vector elements and type (resolution independent), alongside multiple raster images of varying resolutions, and each of those will have its own "effective" resolution based on any scaling you may have done in the InDesign editing environment.

[HenryFernandez]

Thanks for your reply. 

Yeah, sorry actually my background science so I might be mixing concepts. I added some more info in the previous comment about what I need. But from your help and from others I understand that probably the person who asked me to print a document of 1920x1080 pixels in an A3 paper size without rescaling nor distorting the images might be confused as well. As the aspect ratios of A3 and full HD are different, and as pixels are usually squared, there's no way of printing full HD in a perfect A3 size.

[rob day · Accepted solution]

InDesign pages are vector objects and have no resolution—you can place images with any resolution on a page and they will be output at their Effective resolution, which is listed in the Links panel.

InDesign has a Pixel ruler unit which has nothing to do with image resolution, and its output dimensions are a static 1/72". If you change your Ruler Units to inches you will see the output dimensions of your 1920px x 1080px page is 26.6" x15".

If you set up an A3 document as inches (11.7" x 16.5") and change the ruler units to Pixels the page dimension will be 842px x 1191px

[rob day · Accepted solution]

Also, 1920 x 1080 has a different aspect ratio than A3 11.7" x 16.5", so a 1920 x 1080 pixel image would have to be scaled to match the A3 aspect ratio—the Effective output PPI resolution would be 118ppi x 92ppi.