Hello! well i'm new to illustrator (what i've been using is photoshop) and my problem is that I want to save a jpg file, so I create a document at 1920x1080 pixels at 300 dpi and once finished I go to the option of export and set it to 300 dpi and it saves it at 8000x4500? when I set it to 72 dpi there is no problem and saves at 1920x1080, but I want it at 300 dpi and not such a big file that sometimes it doesn't even have enough memory to save.
If someone could please tell whats going on becuse i'm pretty lost at this point.
it doesn't work how you think it works. illustrator's workspace is fixed to a set unit which is 72dpi. if you set your document in pixels and then change your units diplay to inches you'll see that your document really is 15x26 inches. if you export that at 300 dpi then you get your huge file.
in the end, you are working with paper sizes, not DPIs. you can't work at 300 dpi.
you could set your document at 6.4x3.6 inches, but in working units that would be 460x259pixels.
How are you creating "a document at 1920x1080 pixels at 300 dpi " specifically, how are you setting the "dpi"? Illustrator is a vector application which means it's resolution independent. There is no "dpi" setting for documents in Illustrator.
There is the Document Raster Effects Settings but that does not control the document as a whole. It controls any raster effects applied to objects.
To put it in a third way:
When you use pixels as the unit in Illy, it has nothing whatsoever to do with pixels in the normal sense connected to raster images.
It actually corresponds exactly to points, and 1 point is 1/72 of an inch. The document size 1920 x 1080 pixels equals 26 2/3 x 15 inches.
This means that when you Export the artwork as a JPEG at 72 PPI you will get an image of the 1920 x 1080 pixels, and when you Export at 300 PPI you will get an image that is 300/72 times larger which is 8000 x 4500 pixels.
Ok i'm going to reply here but I want to thank everyone for the help because now I understand this better.
So if I want a final exported jpg of 1920x1080 (or other resolutions) at 300 dpi how do I set the initial document? is the correct and only way to do the conversion backwards and set it to 460.8 x259.2 px for the 1920x1080 case (because it is not exactly 1920x1080)
When you save a JPEG, it is the pixel x pixel size, in this case 1920 x 1080, that matters.
You can resize that JPEG in the receiving application to have just about any size depending on the resolution, in this case 300 PPI which will give a size of (1920/300 =) 6.4 x (1080/300 =) 3.6 inches.