Magnifier Lamp Buying Guide | Magnifier Lamp Buying Guide |
Magnifier Lamp Buying
Guide
This is not much of a guide to
magnifying lamps, rather, more of some basic knowledge on the
magnifying lenses. Whether to get a desk lamp type, a table/bench clamp
type or a mobile stand type, is totally your choice depending
on your application and budget. What we could do here is to assist you
to find the appropriate lens. Right now we carry 3 (sometimes referred to as 3D or 3d, same
for 5 diopter and so on) and 5 diopter lenses on many models, and
8 diopter lens on some other. Please understand that 3 diopter does not
equal to 3X. There is a formula you can use if you really want to know
how many Xs a lens is.
D/4+1=X
Where "D" is the diopter number given, and "X" being what we normally
know as the power or strength of magnification. That is, use the given
diopter numer, for instance, 3 to be divided by 4, then plus 1, that
equals 1.75, which is what we call as the magnification strength, often
expressed as 1.75X.
Lens Specification
| |
3D |
5D |
8D |
| Diameter |
5"
/ 127mm |
5"
/ 127mm |
5"
/ 127mm |
| Weight |
0.71lb
/ 320g |
0.93lb
/ 420g |
1.28lb
/ 580g |
| Magnifying
Strength |
1.75X |
2.25X |
3X |
| Focus
Range |
≈
1" - 9" |
≈
1" - 7" |
≈
1" - 5" |
| Best
Focus |
7" |
5.5" |
3" |
| Readable
Area |
Total |
Large |
Limited |
| View
Distortion |
No |
Minor |
Severe |
[Fig 1] 3 Diopter Lens
[Fig 2] 5 Diopter Lens
[Fig 3] 8 Diopter Lens
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Here is an example of a 3 diopter
lens at work:
[Fig 4]
The
lens is about 6" above
the viewed page. Please don't get me wrong, it looks very clear when
you are actually seeing through the lens, only that when we have to
shrink the picture here to put it online, it doesn't appear to be very
clear
as it should be. Please note that the viewed page looks almost the same
everywhere in the lens.
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Here is the 5 diopter lens at
work:
[Fig 5]
The
lens is about 5.5" above
the viewed page. If you compare the image that appears through this 5
diopter lens, with the image above, through the 3 diopter lens, you
will see that the phone listings appear larger. Do you also notice that
some distortion of the text begin to appear towards the edge of the
lens? If you keep looking through the lens for rather long period of
time, you might feel dizzy. That is why we do not suggest to use a 5
diopter lens for reading purposes, unless your eye doc okays it.
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Now the
following is an 8 diopter lens
at work:
[Fig 6]
The lens is
about 4" above
the viewed page. Now, the image (at the center of the lens) apparently
appears larger than the above two. It serves its purpose. Doesn't it?
No sooner than the lens was placed on top of the page, when some
listings went up smoke. (Another
burn mark on the right side of
the fingers, notice?) Very powerful. Unfortunately, you must also have
noticed the readable portion of the viewed page becomes limited and the
rest of the image towards the edge of the lens is so distorted that it
eventually grows unreadable. Whatever your eye condition, this is
definitely not recommended for reading purposes.
We hope the above information is helpful for you in choosing which lens
is more
appropriate for your application.
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