Google has a string of suggestions for website images in addition to just ensuring that the images need to be there in the first place.
Firstly, the search engine does recommend using ‘original’ images. I know that many distributors just use images supplied by the component or system manufacturers; this is fine, but it might be worth asking yourself if the fairly minimal effort of taking your own photos might be worthwhile.
Images should be placed near the relevant text, and should not contain important text themselves. Not all users can access them, and page translation tools won’t work either.
To ensure maximum accessibility of your content, it’s important to provide ‘alt text’ for images. This is what visually impaired readers need, but it’s also something that a search engine can (and will) take advantage of. Title text can add to this, but is unlikely to be significant for SEO purposes.
Finally, use a helpful, descriptive file-naming system and consider using the URL path to help explain the image, if possible.