I'm working in InDesign. I have tried setting image downsampling to 72 ppi when exporting, as well choosing "Do not downsample". Neither worked.

...as well choosing “Do not downsample”...

In addition, set "Compression" to "None" -- it's just below "Do Not Downsample."

I did and it didn't help. The pictures are of different fonts rendered in various browsers. The clarity is the whole point of it.

Wierd! Viewing the document at 73% size renders the type perfectly.

Check your display settings in Acrobat, especially ‘Image Smoothing' (?). I’m afraid this is a user setting, so you can’t really control it.

Ouch. That messes up my whole concept.

So the precentage in Acrobat Reader (or any other pdf viewer) aren't true? 100% isn't 100% in terms of pixels.

No, 100% at Acrobat’s (8, Mac) default ‘system resolution’ of 93 pixel per inch won’t look the same as 100% at a customized resolution of 72ppi. You might assume that most people (on a Mac, using this very piece of software, that is) haven’t changed the default and thus specify an initial zoom factor of ~77,419% in your document – but that neither looks good nor will solve your problem.
Better include links to online images.
F

In other words: your monitor at around 73% displays the pdf at the full 100%.

An idea: upsample your screenshots in PhotoShop to 4 times 73% using the bilinear setting and place these in your layout with a 25% reduction. Don’t use downsampling when PDF-ing.
Could be the way to go…

. . .
Bert Vanderveen BNO

It has to work on all computers, not just mine. The pictures need to be pixelperfect as well.

Does it have to be a PDF? What about HTML?