Fresnel Lens, 100x100mm, Focal Length 50mm, Solar Death ray for Physics Classroom, Solar Heating, Fire Starter, Small Magnifier, DIY Optical Viewing Lens, VR Field,not Glass(Focal Length 50mm)

Fast shipping can’t wait to try it using it for starting a fire when outdoors /emergency situations

Works as described, good purchase.

It was a high quality lens but it was the wrong size for my application

As others have said, this comes in minimal packaging and no storage. I wasn't familiar with this initially but wanted to play around with it outdoors to see if I could use it as a firestarter and so forth. I will attribute it to use error that I was unsuccessful in starting any flames but I did have fun with my 3-year-old grandson who was mildly interested. Of course I will be putting this up so that he cannot access it without me in case he has more luck than I did in focusing the sun's rays! It's acrylic so bendable but has hard edges. Find a good envelope to place it in when not in use.

Nice and sturdy lens. The size and optics properties are as advertised.

Overall this is a really good non-glass Fresnel lens. The acrylic allows much more light to pass through than I expected. The image is clean and the 100mm focal length is a good distance for most work. There are other options out there for a much lower price but the quality is dubious and luck will determine your satisfaction. It comes with a simple square bubble pack envelope. I would recommend cutting it cleanly so you can save it to store it in. I am happy with mine. The price is high but the clarity and quality are really good.

If you have never used a fresnel lens, these little artifacts concentrate the area (in this case a 100 x 100 mm square) into a very small area. The focal point of this one is at around 4". So if you have the sun perpendicular to the fresnel lens, the point about 4" away from the lens will be very powerful.The lens is well built and works as intended. It would be nice if it came in a more permanent protective sleeve so that it can be stored without damaging it.If you intend to give this to a kid, make sure they are always supervised. It is strong to start a fire, harm can be done if used on bare skin or any parts of the body. Also, recommend to use minimum sunglasses as the focal point is very bright.Great product to tech kids and to have fun!

This lens is good but not great for normal magnification or projection uses. It's not super hand holdable and relatively thick. But it has a lot of magnification with a short throw, so it works super fast as solar concentrator. This would be great for a solar oven, and good for any other fresnel lens experiments.