Click for Home

PDF notes & Problems

The Adobe Portable Document Format, commonly known as a PDF file, is unique in common usage. Many of you will have read and used PDF files but it is not generally appreciated how versatile they are - nor quite how important this format is. Before a fuller explanation though, one particular problem needs to be answered. This concerns users of Adobe Acrobat Reader version 4.

It has been noticed that users of certain versions of web browsers, in conjunction with Acrobat Reader 4, are either unable to read a landscape format document at all, or can only see part of it. The reason seems to be something to do with the way AR4 downloads the page from the right hand side rather than from the top like versions 3 & 5. Sometimes waiting longer or reloading the page seems to work. Alternatively, right click on the link and download the file to your own machine and then open it with your reader. This is obviously cumbersome, so the recommendation is to upgrade your Adobe Acrobat Reader (FREE!) from http://www.adobe.com

So what is so good about PDFs then?

  • The whole idea of a portable document format is that it should be electronic; a PDF file is primarily intended to be viewed on screen. "So what is new there?" you may ask. The answer is, and this is very important, is that you will see the document exactly as it was intended. Unlike many an MS Word document, the pages won't change at strange places, the images won't be on the wrong pages and peculiar characters won't appear if you don't happen to have the intended font.
  • "Wonderful", you say, "Why doesn't everyone use them?". In part this is because of the popularity of the products produced by a certain well known software company which are vaunted as the solution to all needs. As you all know this is not the case. Every computer has slightly different software installed. Very few people use the same fonts or even the same printer - and it is the printer drivers, which are necessarily unique to their respective devices, which cause nearlly all the differences in format you will see. If six different people print out the same MS Word document, using six different computers attached to six different printers, then you can almost guarantee the six printouts will vary - sometimes enormously and to the point where the document becomes unintelligible. In contrast, you can print out an Adobe PDF, using any computer (even a Mac) on any printer and you will get an identical output (obviously within the constraints of the printer quality and colours). No other software does this.
  • Once created, an Adobe PDF is not editable in the normal way. In many respects this is an advantage, because it means it cannot be tampered with, but on the other hand it does mean that documents cannot be passed back and forth for corrections and changes. However this is not the intention behind the PDF filetype; it is intended to be a final stage. Use Word, or whatever, and edit this in the usual way, only then should the document be converted to PDF after the document is complete. The way this works is that you use Adobe Acrobat (ie the full commercial program - not just the reader) to print a PDF virtually. If you don't have the required software, you can buy it (~£50 for educational establishments), send it to me or someone else who does, or send it across the web to Adobe themselves who will create up to five free PDF for you click HERE. Alternatively use the FREE Primo PDF software.
  • Many PDFs you will encounter are simply a properly formatted version of the document as it was originally created. This is good in itself, but in addition, PDFs support hypertext links just like any web page or modern MS Word or WordPerfect documents. This makes them especially valuable for archiving where ancient (& modern) documents can be scanned and converted to a PDF which is then viewable on-line without having to remove the originals from storage. Hypertext links can then join these documents within a database in ways which were never previously envisaged - all without even needing a conventional browser. The PDF type is also extremely compact compared with most file types - for both text and images - thus saving archive storage space.
  • Not all PDF documents are non-editable. The Adobe format also permits the use of fillable forms by users who don't have access to Adobe PDF creation software. These are becoming more popular on-line as an alternative to web based forms which are notoriously unreliable and may be more susceptible to security risks.