Effective PPI written in dimensions

[Sparven]

Some of the links in my InDesign-file have an actual PPi of 72, but the effective PPi is written out like 801x762 (instead of 300 for example) and I don't know how to interpret it. What does ths mean? Does any one have an answer?

[jmlevy]

It means that the physical size of the file has been non proportionaly reduced:

[Sparven]

Okay, but is there a way to tell what the effective ppi actually is?

[jmlevy]

Yo have 2 effective ppi: horizontally (x axis), it is 801 and vertically (y axis), it is 701. But if you simply correct the x and y percentages and set them up equally, no more doubts…

[Sparven]

Okay! Thank you so much!

[Test Screen Name]

It's easier to see what's happening with an example that is more dramatic.

Suppose you have a picture that is 300 ppi effective resolution. You make it double size, the effective resolution is 150 ppi.

But suppose you just stretch it tall, so the height is double, but the width is unchanged. InDesign will now show it has an effective ppi of 300 x 150 ppi.  So InDesign is giving you valuable information that perhaps the picture is distorted. 

Now, what effect does this have on quality? You should treat the quality as being the LOW number - so this example, the quality is essentially 150 ppi quality.

[Derek Cross]

The shotcut to establish the Effective PPI is F8.

[rob day]

Hi @Sparven, also InDesign doesn’t allow you to resample a placed image, when you scale an image both the pixels and the image output dimensions get scaled. It works the same way as Photoshop’s Image Size dialog when Resampled is unchecked.