Puzzling Preferences Setting 'Custom Resolution'.

[Bruce_G_Abel@adobeforums.com]

Hi, I am running latest version of Acrobat Professional under 10.4.7. This issue is a little tricky to explain clearly, so sorry for the long post.

I am working with the program on a Macintosh Powerbook G4. It has a screen resolution of 1280 x 854 pixels.

I have noticed that there is a setting in Acrobat Preferences, under 'Page Display' (chosen from the left hand pane). This setting (there are 2 related settings) seems to control how acrobat scales the page to the screen. The first setting 'Use System Setting' had a 101 pixels per inch suggested. The other setting was not selected (can't remember if that's the default) and it was set initially to 72 ppi (which as far as I know is a typical Macintosh screen 'resolution').

I have no idea why my systems resolution is calculated / equated to 101ppi, I suspect it's to do with 'dot pitch' (which I've found to be a term bandied around more in the PC world). I am guessing that to cram 1280 x 854 pixels into a 15 inch display the dot pitch is finer than the old mac standard of 72 ppi (or am I barking up the wrong tree here?)

I have noticed a strange occurrence when rendering thin lines on a particular PDF. In 'Preview' (the mac OS X application) the PDF renders the thin lines nicely. In acrobat they looked quite thick and therefore inaccurate. They were in reality defined as .5 point thick lines, so should not have rendered thick. To fix this I monkeyed with the smoothing settings, and found that switching smoothing to 'OFF' for 'Lineart' fixed the problem. It didn't seem like a particularly elegant fix.

That's when I noticed that having the 'Lineart' smoothing set to 'ON' results in a properly rendered thin line if the 'Custom Resolution' is ALSO selected using 101 ppi.

Could someone please give me an in-depth as to what is actually going on here so I can understand it. I really want to trust the onscreen preview so I can do soft-proofing. The acrobat program help says the following (not particularly verbose or helpful)...

'Use System Setting'
Uses the system settings for monitor resolution.

'Custom Resolution'
Sets the monitor resolution.

Thanks for any help you can give.

Regards,

Bruce Abel.

[Alex_DeJaneiro@adobeforums.com]

I'm having the same problem with line art and fonts not smoothing properly in Acrobat. I use PDF files to soft proof with my clients and they always have to print the file out because the onscreen preview doesn't render as well as it should.

When I compare the same document in Apple's Preview and Acrobat, the document always looks fine in Preview, but lines or fonts aren't smoothed properly in Acrobat.

I've been monkeying with the page display setting myself without success, and would also like to hear from someone who knows how to adjust the preview settings to fix this smoothing problem.

cheers
adj

[Bruce_G_Abel@adobeforums.com]

Hi Alex, have you tried the settings I suggested on your own machine?

ie; "Lineart' smoothing set to 'ON' results in a properly rendered thin line if the 'Custom Resolution' is ALSO selected using 101 ppi."

Give that a go first and you should find that it basically fixes the rendering issues, making it display in a similar way to "Preview'. I suspect that the settings that result in the unexpected rendering are default values. Perhaps Adobe may decide to change these defaults if that's the case, as I didn't find it particularly good.

I am guessing if it's a default your clients have probably got the same settings, so are also viewing it with 'thick' lines.

Hope this helps.

I'm still hoping someone can clarify the "custom resolution" issue as the documentation is pretty poor.

Regards,

Bruce.