I thought I would try and add some missing portrait photographs to composer pages where I can find them on the internet. Obviously there is a difficultly in determining whether they are public domain when no information is available about the photographer. Presumably the copyright law of the country where the photograph was taken applies. Where a photograph is to be found on a library site (not wiki) is it safe to assume it is public domain where the composer has been dead for more than 70 years and no information is given about the image; ie photographer unknown, or should one be writing to the website owner for permission to use the said image.
Obviously this is a case by case situation and should it be tested each time with copyright reviewers before uploading an image?
The specifics in this case are the image of Sergey Yuferov on this page.http://museum.lib.kherson.ua/en-yuferov.htm