China Helmet Magnifier for Repair, Find details about China Magnifier, Loupe from Helmet Magnifier for Repair
Material: ABS+ resin lens
[characteristics] : delicate, concise and generous
[packaging] : color box
Function: local magnification, real and fake coin identification, stamp collecting, circuit inspection, antique appreciation, jade and so on
[weight] : 120g
[purpose] :
1. Inspection, processing, installation and repair of various operations in the electronic industry.
2. Facial skin and pore observation, manicure and ear picking in the beauty industry.
3. Sculpture and appreciation of works of art.
4. Check and repair cameras, clocks, etc.
5, usually used when people read, especially for the elderly, students and other reading in dim light.
Dentist, tailor, embroidery, etc.
7. Features of finance, taxation, stamp collecting, jewelry, printing, agriculture and other products.
The magnifying glass that the old person reads a book to read a newspaper is in commonly 4 times --10 times between, the most commonly used is 5 times, 6 times, 8 times, 10 times etc.Some people think higher multiples are better, but they are wrong.The higher the multiple, the thicker the lens, the smaller the diameter, and the harder it looks.High-power magnifier can only see a word or even only half a word or a stroke of a word at a time, and the word's edges and corners are seriously distorted, with pure white LED light source is not suitable for reading, high-power magnifier is suitable for observing the stamp printing point arrangement, crack of porcelain jade grain, etc..
If the eyesight of the elderly is ok, 4 times, 6 times is recommended.
The person that this and myopia match glasses is same, the glasses that match is not degree is higher had better, suit you, just be the best.But some people think those who buy multiple tall seem to occupy cheap, total want to buy highest times, buy go back to want to change again, just know high times read a book is not convenient.
Imaging principle: optical lens made of glass or other transparent materials with curved surface can magnify the object to image, as shown in figure 1.Object AB, which is within the object square focal point F, of size y, is magnified into A virtual image A'B' of size y'.
The power of a magnifying glass
Γ = 250 / f '
Where 250-- visible distance, in mm
F '-- focal length of magnifying glass, in mm
The magnification ratio is the ratio of the viewing Angle of an object with a magnifying glass at a distance of 250mm to the viewing Angle of an object without a magnifying glass.