CDS image guidelines


The guidelines outlined in this document are under discussion and subject to change - see comments in the attached document

Guidelines for Images on the CERN Document Server

The following guidelines are intended for writers, editors, photographers, picture editors and web editors contributing images to the CERN Document Server at CERN.

Treat every image as a separate entity. Every image should be accompanied by enough information for a historian in the future to understand what it shows.


High resolution – [fix a minimum?]

Add images to a collection. The images should be different – the same subject from different angles, for example, or a collection of images on a theme.

Photographers should select only their best images – those that most accurately and most aesthetically portray the subject.  As a general rule, a few good images is better than an exhaustive collection from every conceivable angle.


60-character maximum, including spaces

Titles are the "headline" for a collection of images. Titles should be short and clear. They should contain enough information for a picture researcher to know quickly whether or not to click into the collection to find the image they need.

Good examples:

  • German Finance Minister visits CMS
  • Upgrade work on the ATLAS silicon detector
  • CERN Open Days – Presentations at the SM18 magnet facility
  • Civil engineering for LHC tunnel near Meyrin

Bad examples:

  • LHC 16 July
  • ATLAS, CMS, NA62
  • 15 July 2014 - Chief Financial Officer, RWE Supply & Trading GmbH, Federal Republic of Germany M. Krebber visiting the LHC tunnel at Point 1 with Technology Deputy Department Head V. Mertens; S. Lettow and C. Rembser present throughout


40-word maximum

Descriptions  appear beneath a collection of images. The description should add useful general information about the group of images that cannot be discerned from the visuals. The description can be general, as each image will have its own caption containing more specific information. Ensure you add the date the images were taken, as this is not always the same as the date they are uploaded to CDS.

Good examples:

  • The King of Thailand, Bhumibol Adulyadej, visits CERN accompanied by a group of Thai government officials. Images show LHC point 1 and the ATLAS and CMS caverns. 
  • Virtual visit to the CMS underground area. Some 200 university students connected at once from seven locations around Bulgaria.
  • Engineering work to replace a faulty connection inside the CMS detector. All workers shown are from the Cabling group in the CERN Technology department.

Bad examples:

  • CERN Science Camp


Captions should give specific information that is absent from the title and description, or cannot be discerned from the images.

For example, you could tell from an image that a woman is working on the detector, but you need the caption to tell you her name, job title and which technology she is working on.

When writing the caption, think: What are the full names (Christian name and surname) of the people in the images? What are they doing? Where were the images taken? When? What objects are visible in the image?  

Captions appear in the CDS single-image view.

Each image has a CDS image ID, a number in the following format: CERN-AA-1234567-89. To see the image on its own, append the CDS image ID to the following:

This gives, for example:

Good examples:

  • Dr Markus Krebber  (wearing red tie) Chief Financial Officer  of RWE Supply & Trading GmbH in the Federal Republic of Germany, visits the LHC tunnel at Point 1. Behind him, left to right: CERN Deputy Technology department head Volker Mertens, CERN Director for Administration and General Infrastructure Sigurd Lettow and ATLAS physicist Christoph Rembser.
  • Left to right: CERN engineer John Doe, CERN physicist Jane Doe, and Bobby Everyman of Accelerator Construction limited. In the LHC tunnel at point 1. The blue object is a dipole magnet.

Bad examples:

  • VIP visit
  • John, Terry, Dan and Jenny in the LHC tunnel [Where? Which is which?]


Use existing keywords  wherever possible. A list is available on the CDS image input form. Keywords should be lowercase, except in the case of acronyms. Add a new keyword if it is likely to be used in future – for example a recurring event or experiment.

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