Summer is the perfect time to host an outdoor movie night, so jump on these post-Prime Day deals on video projectors, or you'll be dragging your TV into the backyard all summer. Amazon has kept prices low on select projectors, whether you're looking for a pocket-size model like the Smart Mini, or a more upscale projector like the Anker Mars 3.

• Sovboi outdoor projector: At 42% off, you can pick up this "everything you need" projector for only $249, only $10 more than the Prime Day price. It features built-in Google TV and AI Voice Control, and it's designed for outdoor use. It also features automatic focusing, which means you won't need to spend as much time getting the picture to look clear. One thing to be aware of with this projector: The description says it "supports 4K video," but that just means it will accept a 4K input signal. It outputs in 1080p. If you're looking for higher resolution, you'll need to look elsewhere. Also, the prominent claim of "3000 brightness" should be ignored; it's a decently bright projector, but that number doesn't mean much (see my note on "Lumens" below).

• Smart Mini Projector: The main selling points of this mini projector are its "throw it in a bag" portability and its low price, and it's still 35% off. It weighs less than three pounds, it's wifi and Bluetooth compatible, and it features built in Netflix, YouTube, and Prime Video. On the downside: The claim of 1800 ANSI Lumens is dubious on a machine that costs $129—this seems like a strictly dark room projector.

• Anker Nebula Mars 3 Air: This projector's Prime Day price of $399 has gone up to $469, but that's still 20% off the list price for a solid piece of gear. The Mars 3 bridges the gap between budget gear and multi-thousand-dollar home theater centerpieces. Unlike some cheaper units, the setup is effortless, it runs Google TV with native, crystal-clear 1080p Netflix right out of the box, and the automatic image software sets up and sharpens pictures in moments. It also packs dual 8W Dolby Digital speakers for rich sound. The cons: according to Amazon's reviewers, the battery life is limited to about 90 minutes of full power use, so you'll need to run a cord to the backyard if you want to finish an entire movie. Its 400 ANSI lumens rating is lower but at least honest, making this a better bet for a pitch-black room or a nighttime campout.

A note on lumens

In the advertising copy for budget projectors, you'll often see claims like "9,000 Lumens!" or "3,000 Brightness!" on $120 machines from brands you've never heard of. Meanwhile, more expensive projectors from established brands like Anker tend to make more modest claims about "ANSI Lumens."

This is because "ANSI" or "ISO Lumens" are a real measurement of light output of a projected image, but "Lumens" is a vaguer term that can refer to anything from a measurement at a light source to some other creative definition of the term. Cheap projectors from no-name brands can be great—each one listed above has more than 4 stars from reviewers—but you should take any outsized Lumens claims with a huge grain of salt.