[Posted by Chuck Almdale]

Wikimedia Commons is a vast storehouse of photos and other images which anyone can use with the stipulation that you’re supposed to credit the source, just as with any of the stuff people steal all day long from the web and never credit anyone. So if you’re one of the 99.998% of photographers whose photos will never be sold to anyone, but who think they’re good and want to share them with a larger audience than their maiden aunt and her cat, in this case the entire world, this is a great place to send them. I have no idea how many thousands of photos I’ve uploaded from Wikipedia and Wikimedia over the past 15 years to use in the various things I write and post, but it was probably 500 or so just for my 138-installment-series on the early Mongol Empire, the Kyivan Rus,’ and why the Mongols didn’t conquer all of Europe. [Yes, that was a plug.]

And…I just found out they have contests. A different topic every single month. This has been going on since 2013. They also have longer contests. For example there is a year-long, biannual, science competition going on right now, and it has a U.S.-only section.

All you need to know about the Wiki Science Competition in the United States is at the link below. From the snippet above you can see there’s a wide variety of acceptable “science” photos. I particularly like the shot of the tree canopy, appropriately titled “Crown Shyness” by Mirai Kambayashi. There are several categories: People in science, Microscopy, Astronomy, Non-photographic media, Image sets, Wildlife and nature, & General. The contest runs Nov. 1 – Dec. 15, 2025.
https://en.wikipedia.org/wiki/Wikipedia:Wiki_Science_Competition_2025_in_the_United_States

But that current contest barely scratches the surface. Linked below is a page that explains everything, and has a ton of example photos people have sent in. The winners are decided by those who send in photos: you can’t vote for yourself, photos must be new to the commons, you can submit as many as you want, and a few other caveats.
https://commons.wikimedia.org/wiki/Commons:Photo_challenge

The November 2025 contest is on glaciers. Here’s a screensnip of a few photos:

Categories can seem screwy, but no screwier than the endless shots of people about to eat a burrito or other presumed edible with which people entertain each other these days. For example the October 2025 contest is (as it’s still open) on…Freight Cars! Here’s an example:

The September 2025 contest was on…yes, you guessed it…bricks!

This just keeps going. As said above, these contests started in 2013. It’s all on this page, and you can branch out from there. Check it out. Maybe they’ll soon be doing a contest on…eating desserts!
https://commons.wikimedia.org/wiki/Commons:Photo_challenge#
There’s a table of contents on the left side of the page that can get you to any of the above photo sets, plus plenty more.