“This is the best picture I was able to find on the Internet.”
There’s no sin in finding images on the Internet. I’m a big fan of Flickr and Google Images, too.
But there are two problems here. First, it’s rarely a good idea to draw attention to aspects of your talk that you recognize are weaknesses.
Second, I’ve seen people put up crummy pictures taken from the Internet of scientific equipment that they use practically every day. And these are not difficult pieces of equipment to photograph because they are very large or very small. No, these are very mundane objects that sit on a benchtop, like PCR machines.
I’ve seen people put up crummy pictures of some other lab doing a procedure when it’s a procedure that they themselves do all the time.
You look witless and lazy when you say, “This is the best picture I could find on the Internet” if you could have taken a picture yourself.
High quality cameras are almost everywhere now. Even if you are one of the increasingly small number of people who does not have a smartphone, you probably know someone who does who would be happy to take the picture for you.