My eyes are dim, I cannot see…
As I sometimes have to peer into the back of gloomy equipment cabinets, I found a magnifying glass a valuable addition to my toolkit. However, there are times when having one in my wallet would have proved handy. So, today, my eyes lit up when I spied a credit card sized one at W H Smith in our local shopping centre.
However, on unpacking it, the apparent magnification is a fake! See what the backing card looks like without the viewer in place.
It does actually magnify, but at a much longer distance than the packaging might suggest. As the viewing angle is very narrow, the camera view here is somewhat distorted.
A more oblique view shows the actual distance required to get that 2.5x magnification.
This is a very good practical example of a fresnel lens where a very thin construction still has the magnifying effect of a much thicker lens, albeit with some image degradation. It even has a built-in tiny LED for use in dark places, such as for discreetly reading a theatre programme.
You can buy these Magnicards online for £4.99 and it does work, even if it doesn’t quite do what it implies on the box.
December 29th, 2007 at 6:48 pm
I must admit to being a bit of an EDC nut. Apart from mobile phones and portable music players, us Brits seem to be on the whole much more averse to EDC than Americans and those on the continent, so I was happy to see JML selling this product. Luckily, my eyesight is fine for reading. In fact, my optician tells me I have 20/21 vision i.e. I must have answered a question wrong because no one can get that score! However, it frustrates me when I have to get up on a stepladder to read a label at work or walk down a platform to read the scrolling screens at the train station. Therefore, I intend to invest in a monocular of some description.
December 29th, 2007 at 9:22 pm
Simon- your post went into the moderation queue because it is set to default- embargo posts with 2 or more links. I notice it doesn’t put you in recent comments even after approval which is odd.
My vision is a right pain at the moment due to the Diabetes thing- it varies with my blood sugar levels & the doc has told me that getting my prescription changed would be counter-productive at present. So I’m reading things up close with specs lifted up (I’m very short sighted anyway) & sometimes middle vision with them on the tip of my nose.
I appreciate font resizing in Firefox and curse sites that hard code their size.
On the EDC front, I’m now a notebook and pen man, great for jotting ideas down.