I am currently studying on a forensic course and we are starting to dabble in forensic photography and other things where taking high quality photo's can make assignment work really stand out. The university cameras are very poor quality and we can not book them out for very long (which makes photographing experiments lasting over a day difficult as we get inconsistencies in the type of cameras available to come out on loan and it generally makes work look bad) So I have decided to go out a buy myself a half decent bridge camera which I can use for uni and in my own time. I have an assignment due soon in which we are supposed to examine a mock crime scene. Is there such a thing as a write only SD Card? I seem to recall being told about them but for the life of me I can not find one. As far as I recall one of the primary rules of photographing a crime scene is delete no pictures so if I get a write only one I can put it in my assignment that there is no way pictures could be deleted. I am a bit of a photographic mong in all honesty.