When HN users recommended it
1 HN user recommended this in 2019, in one comment.
20072026
Each tall tick is one HN user's first recommendation. A short tick is the same user again. Click a tick to jump to the comment.
1 HN user recommended this in 2019, in one comment.
Each tall tick is one HN user's first recommendation. A short tick is the same user again. Click a tick to jump to the comment.
Here's one from Amazon for $8 that's A4-sized and probably weighs a few grams. Great for magnifying or building a solar oven. If you can find one a meter square, you could probably weld with it in full sun.
[0] https://www.amazon.com/11-75-Fresnel-Magnifier-Projection-PR...