$5.44
This is one item of a 260 X 177mm (approximately 7 X 10.25 inch) rectangular plastic fresnel lens. It is slightly smaller than A4 paper. The focal length is approximately 30cm. The magnification is a theoretical 3X based on the focal length. The material is optical PVC. You can use these as a traditional magnifier but they have a variety of fun uses such as concentrating sunlight onto small photovoltaic solar cell batteries and setting fire to things like scout camp-fires in sunshine. The thickness measures 0.53mm. The material can be cut with strong scissors or a knife.
It's worth mentioning that these are not suitable for use as reversing or side-vision lenses on cars or trucks. You need a diverging lens for that, and they are usually specially made so that they also change the angle of vision off-centre.
It is best to keep them out of the sun when not in use. I have the credit card sized items on another listing in my etsy shop.
I've used these mounted in a frame to project tight beams from infra-red or visible LEDs for light based experimental free space voice or RF link transmission systems, using another similar lens and a photodiode at the receiver end. With a keyswitch on the LED you could use it for morse-code signalling over a substantial distance like an Aldis lamp.
1 business day
I'll do my best to meet these shipping estimates, but can't guarantee them. Actual delivery time will depend on the shipping method you choose.
Buyers are responsible for any customs and import taxes that may apply. I'm not responsible for delays due to customs.
Just contact me within: 14 days of delivery
Ship items back to me within: 30 days of delivery
Buyers are responsible for return shipping costs. If the item is not returned in its original condition, the buyer is responsible for any loss in value.
Please contact me if you have any problems with your order.
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Feb 12, 2025
Thanks again, these are just perfect.
Oct 4, 2024
Just as described and perfect for what I needed it for 😊
Sep 20, 2024
None none none none none
Sep 25, 2023
Great magnifying screen, thank you!
Feb 2, 2023
Exactly as ordered and in good time!