Digital Collections - Frequently Asked Questions



Technical questions

Proposals for digitization



  • How do I search the Digital Collections?

Using the simple search: Enter one or more words into the search box at the top of any Digital Collections’ page. The simple search automatically searches all metadata and (when available) full text. The advanced search allows you to limit your search to specific fields (author, year, etc.).

  • Why is the box “Search book” not always available?

The “Search book” option is only available if Optical Character Recognition (OCR) has been applied.


  • How can I rotate a page?

Choose the page that you want to turn around (the tab “Page” should be highlighted in blue). Then use one of the arrow buttons right above the image to rotate the page 90 degrees to the left or to the right. Drehung

  • How can I enlarge an image?

When you have chosen a specific page, you will find a button with the symbol of a magnifying glass. Click on this symbol and you can look in detail at a portion of the image. Now you can navigate on the image by using the arrows which you find in the top left. You can also zoom in closer by double-clicking or by clicking on the “+”-button. You can also click and drag to zoom in on a specific region in the image. Please note: wait a moment until the image is fully loaded. The blurry image will get sharp. Zoom

  • What does the category “Contents” contain?

When you click on “Contents” the structure of the book will be displayed. It is a list of the parts of the book which includes the chapter headings, but also information like front cover, back cover etc.

Technical questions

  • How can I download images or print them?

Select your chosen image. Right click on the image and choose “Save picture as”. Choose the directory you want to save it in and click on the button “Save”. Now you can print the image by using the printer menu. Please note: When saved from the internet, the image has a resolution of 72 dpi (monitor resolution). You can find images with a higher resolution in the PDF documents. You can download and print either the entire book (category “Title”) or each chapter (category “Contents”) as PDF files. If you need scans in reproduction quality (e.g. for publications), please refer to our Gebührenordnung (schedule of charges).

  • I cannot download the PDF document. What can I do?

This may have different reasons. One reason could be that you are using Firefox with the Acrobat plug-in. In this case, the downloading of files is limited in time. If you have got a slow internet connection, even medium-sized files may lead to the error message that the file is corrupt. Usually, it may help to download the file from your web browser (right-click, then choose “Save file as” or the appropriate command depending on your browser) and then open the saved file. Alternatively, you can download smaller sized documents. You find them for each chapter by clicking on “Contents”.

  • What is the resolution of the PDF files?

PDFs are automatically generated for the entire work. Because of large data volume, these have got a width of 1000 pixels. For large-sized materials (e.g. folding maps) the PDFs are created with a width of 1500 or 2000 pixels. You can find the PDF files by clicking on “Contents”. Please note: Because very large-sized materials are reduced to the format DIN A4 (printing format), even a width of 1500 or 2000 pixels will not lead to the desired image sharpness. In this case you can look at the image in high quality only by using the zoom function. If you need scans in reproduction quality (e.g. for publications), please refer to our Gebührenordnung (schedule of charges).

Proposals for digitization

  • I would like to make a proposal for digitization. Is that possible?

All persons with a membership card from the ULB may send us their proposals for the scanning of books via email. Digitization is possible under the following conditions:

  • the author has been dead for at least 70 years,
  • the books are in the holdings of the ULB and were published before 1900,
  • the condition of the book allows a digitization.
After you have submitted your suggestion, we will check whether digitization is possible and you will receive our response. Please kindly note that the time required to scan the books varies. Please also note that the books proposed to be digitized will be scanned according to predetermined conditions. If you need scans in reproduction quality (e.g. for publication), we can digitize works from our holdings. A fee will be charged for this service. If you have any questions concerning reproduction, please contact us via email. For an overview of digitization fees, please see our Gebührenordnung (schedule of charges).

If you wish to publish an image, including as part of another website, we would be pleased if you would send us a copy of the publication you are using the images for or send us an email with the URL (email). The images on our website are thumbnails and compressed. To obtain higher quality copies, we recommend placing a reproduction order. If you have any questions concerning reproduction, please contact us via email. If you wish to use our images on websites, please cite the source as follows: “Universitäts- und Landesbibliothek Düsseldorf, urn“. Example: Universitäts- und Landesbibliothek Düsseldorf, urn:nbn:de:hbz:061:2-21508 . If you are using several images you may as well shorten to ULB Düsseldorf, urn:nbn:de:hbz:061:2-21508.


  • How do I know what’s new in the Digital Collections?

Our RSS feed will keep you up to date on the latest arrivals. To subscribe, please click on the RSS feed symbol.


  • I would like to assess the value of a book. Who can I contact?

Unfortunately, we do not appraise books. Please contact a local antiquarian bookseller or use websites like Zentrales Verzeichnis Antiquarischer Bücher ( )

  • What can I do if my questions are not answered here?

Just send us an email. We will be pleased to answer your questions.