Driver resolution

Question

I am looking for better resolution in my pdfs. 
 Background is we are moving towards 'full plan sheets' (or what you would call it in English). 
 Can be very large 'sheets' like 2A0, 4A0 etc when you want to plot a full plane in 1:50. 
 
 What settings in MicroStation sets the quality/resolution in the printed pdf? 
 This? 
 
 What is the highest number I can set? 
 600 dots per mm. That is a lot! mm on what ? 
 I have feeling Plot dialog PAPER(ABDspeak)/Usable area(OBDspeak) play a role here.

Lorys · Answer

it depends on a lot of things first 
 are you using sheet model paper size and scaling the model down to the paper or are you scaling title block paper frames up to the ground in model space? 
 Do you have rasters attached? ie air photos then you need to change the raster resolution / quality down 100 % ( your says 100, 000 ) remove the extra 0s and comma and say make it 75 would be fine for most jobs. 
 Now the DPI will make a big difference to pdf resolution quality especially if users use the zoom function in a pdf reader... 
 So if your 600 dpi isnt cutting it try 900, then later try 1200 but this will significantly increase the pdf size. 
 Under the other settings there are other options for advanced which make the text searchable and the pdf georeferenced these may be turned off or on it too may also affect pdf size, I don't like changing text searchable feature its too useful. 
 The compression type can also affect raster resolution and pdf size the default is zip as I used a lot of airphoto back ground I changed it from zip to jpg. 
 Lastly for viewing with Adobe acrobat when zoomed in too much the magnification makes things like text into fat blobs and lines too thick and you cant really read the text, the user needs to be trained to use control 5 ( if my memory is correct) and this will toggle on / off line weights making super zoomed view text very easy to read.... 
 I used to do a lot of roll plots typically 5 meters long and A0 height as the width and if they needed to read tiny text, so I calculated the min size text in cad to work it for min size on the prints or pdfs annotation scale helped this a lot, on paper we found min text for clarity was 1.8mm high on the actual paper finished plot size.. 
 I don't know about other peoples experience but I found a lot of trial and error was needed to establish best practice for roll plots and configuring the pdf.pltcfgs and I made several deferent ones for specific conditions and sizes.. 
 But I can't stress enough the educating users in adobe acrobat weight on off toggle (control 5 ) when zooming right in ...it doesn't alter the pdf as they are read only .. its a view setting toggle in the viewer. 
 Most of my plans were for road works so they really were just maps with notes on them so text visibility was very important to us.