Recent content by Atrika

Yes, I see. Thank you all for your help.

If F = focal length / diameter, it means both are equally important. Is there a way to find out the focal length of a magnifying glass before buying it ? The only thing written on the boxes is the magnification and the diameter of the lens.

Interesting.

Hi Tim, isn't it also affected by the magnifying glass' ability to pinpoint light? ex: I have a 2" magnifying glass that produces an image of the sun of 2mm I have a 4" magnifying glass that produces an image of the sun of 4mm Both images will have the same heat output/size so the 4"...

Hi, I'd like to know what makes a http://tinyurl.com/4dp9ocl" better at starting a fires by focusing the sun light. Is it the magnifying power, it's size, it's thickness (etc.) ? Also, is there a formula to calculate it ? Thank you. -Philippe