Does anyone know what image extensions CIVI recognises.
I want to upload .TIF images to civi contacts. Is there a way to do this as the extension is not recognised.
You can add file types in Safe File Extension Options in the admin console. (I don't know if it's advised, but it's certainly possible :)
Go to Administer > System Settings > Safe File Extensions, then click 'Add Safe File Extension'. Enter the file extension (without the dot) in the Label field, make sure it's enabled, then save.
Edit: However, this doesn't actually help with .tif files. TIFFs aren't meant for web use, so (presumably) the image processing in CiviCRM or the CMS isn't designed to deal with TIFF files - it looks like CiviCRM has an additional check to stop the upload because of this. There are probably modules for Drupal that will add this capacity (Imagemagick comes to mind), but I don't know if they'll be picked up by CiviCRM.
If you don't need the images to be TIFF files, I'd recommend using a progamme like Irfanview ( http://www.irfanview.com/ ) to convert them to jpgs.
If you do need to have the files as TIFFs, then add a custom file field for the contact record - this will allow you to upload the files, but won't display a thumbnail. (You can always upload a jpg version as well to get the thumbnail).