Two things about adding images to a PowerPoint (or other) presentation:
Google Images can be a great place to go if you want to get some idea of what sorts of images are out there. Use an Advanced Google Image Search to filter by size, resolution or topic, and to find images that are free to use, share, and even modify.
As shown in the image below, you can search for an image and then limit to images in the public domain and under Creative Commons licenses
Click on Tools
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Use the links in the tabs of this box to find images online in the sources listed below.
Open the guides below to learn more about finding and using images, as well as more specifics on how to cite them.
Google Images is a great tool to see the work of many photographers. For your presentations, however, the images may not be high enough resolution to project well. It's possible to find useful images with introductory information, and you can even use the advanced settings to limit to works that are in the public domain
The image below shows how you can use the built in Tools option in Google Images to limit to Creative Commons images.
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"The key goals of The Commons on Flickr are to firstly show you hidden treasures in the world's public photography archives, and secondly to show how your input and knowledge can help make these collections even richer."
Use the search box at the top to find images or scroll down to view albums and recent uploads:
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Wikimedia Commons contains, according to the site, "a collection of 58,396,226 freely usable media files to which anyone can contribute."Files include images, audio, video, animations, maps, and other multimedia. Users can choose from multiple images sizes when downloading, and each image is often accompanied by information about the work depicted as well as copyright information.
Image Source: "PNG logo with text" by Wikimedia Foundation is licensed under CC BY-SA 3.0
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If you're searching for an image to republish (on a poster or in a paper, for example), you'll need to make sure you have the right to do so. Copyright holders can use a Creative Commons license to assign usage rules and let users like you know what can and can't be done with images. Use the Openverse (formerly Creative Commons CC) Search page to find licensed images that you can use for scholarly purposes.
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