Images in PDF appear blurry on select PCs

[Krishna Gordhan]

Hi all, has anyone come across an issue where a PDF is exported at hi-quality and all images are hi-resolution and the PDF will appear fine on your machine but if viewed on a different machine the images appear blurry?!?

I am in this very situation…

I have a client who has been exporting PDFs from InDesign (Hi-quality and all images are hi-resolution) but when their customers view the PDF on their own PCs they complain the images appear blurry. I've viewed the same PDF on my MacBook Pro and everything appears fine, all images appear tack sharp. The client has a theory that their customers are using Acrobat Reader and since they don't have Pro the images are downgraded. I've never experienced this before or even heard of such a notion.

Has anyone else encountered anything like this?… or have a theory

Cheers

[Dave Merchant]

There is no difference in the way Acrobat Reader and Acrobat Pro render PDFs; nothing is "downgraded" in the free Reader software, and image objects on a page only have one stored set of pixel data.

In Acrobat/Reader's preferences there is a "show large images" option but all that does is turn high resolution bitmaps into gray boxes, it's an ancient feature designed to make scrolling faster on low-spec computers. You might ask them to try toggling "2D graphics acceleration" but I can't see why that would blur anything.

It's possible (likely) the customers are using completely different software. Most just open PDF files in a Web browser, and let the browser's internal JavaScript-based engine handle it. They are, to say the least, limited in their abilities. However that would not be an Adobe or PDF problem. The whole point behind PDF is that a "compliant" rendering application should always display the page exactly the same (assuming the hardware is suitable).

[Krishna Gordhan]

Hi Dave, Thanks for your response. I was talking to a colleague earlier and he mentioned something about Adobe Reader bundled with Windows 10 and that he's experienced issues with how the "bundled Reader" displayed certain file types compared to the Pro version eg A PSD file placed in an InDesign file then exported as a PDF displayed differently between the two versions. Personally, I'm not up to play with any of the Windows products so I've asked him to have a look at my PDF as well as some other people I know that are running Windows 10.

All I know is that the customers are all PC/Microsoft based and am now wondering if this is the root of the issue. I'm waiting to hear back on the feedback. Will post what I hear back

Cheers

K

[Test Screen Name]

There is a bundled PDF reader with Windows 10.  It was once Microsoft Reader, now it is Microsoft Edge. But it’s very important to realise that this is NOT Adobe Reader by another name; Adobe have no connection to it. This is made entirely by Microsoft. There are now many PDF readers, most people now have no Adobe software at all. So in tracking down this issue it’s important to find the actual software used. Also, many users ASSUME they are using Reader because they downloaded it, but then view in Chrome or Firefox or Edge or Safari or their mail app or on a phone or tablet... none of which use Acrobat Reader even if you have it. 

[Test Screen Name]

Oh and one other thing: people often overlook the simple question: do ALL PDFs look bad on your computer. "Oh, yes, all of them, sure... "  

One technical thought: this may be high resolution monitors, on which many apps will display everything at low resolution. That would include older versions of Adobe software, so always check versions too, and ask for monitor spec when you're doing tech support.

[Krishna Gordhan]

Thanks for the insight, that's probably the one thing I'll never be able to check is what everyone is viewing the PDF on, since all my clients customers are based abroad and to go to each individual to see what they're setup is will be too time consuming. 

[rob day]

Acrobat Reader and AcrobatPro have Page Display Rendering Preferences that affect image and line anti-aliasing. Those settings are controlled by the client:

[rob day]

Also, the affect of the Page Display Rendering prefs would be more or less obvious with different types of images and the zoom magnification: