How does Carson measure Magnification?
Magnification, also referred to as magnifying power, depends on the focal length of the lenses used
in an optical device. At Carson Optical, we calculate the magnification based on measurements of the
actual product, not the theoretical properties of the lenses. We use optical measurement equipment,
such as a lensometer or lens clock, to measure the power of a lens. This provides the user with much
more accurate results of magnification, compared to other methods which are based upon the lens mold
or intended design that might not correspond to the real life product.
Our advertised magnifying power (MP) is based upon the standard industry equation (also referred to
as “trade magnification”) for the maximum magnifying power corresponding to ideal viewing
conditions, and depends on the diopters of a lens or lens system. The diopters of a lens is
equivalent to the inverse of the focal length in meters.
MP = D/4 + 1
The above magnifying power is related to the nominal magnifying power as follows:
MPnominal=MP-1=D/4. The diopter value (D) used for these calculation are based on
empirical measurements from actual samples of the individual lens or lens system, using a lensometer
and/or lens meter with a confirmed zero and calibrated to at least two points using known reference
standards. The diopter measurement is made according to the back focal length (BFL) specified by the
directionality of actual usage of the lens or lens system. The testing is repeated over a
sufficiently large sample set to calculate the average actual magnification. The results are
converted to magnifying power and rounded to the nearest half power. For example, magnifying powers
What are the advantages of Acrylic Magnifying lenses?
Acrylic magnifiers are extremely lightweight and durable. They are shatterproof and difficult to
break. Acrylic material also makes it possible to have a smaller, more powerful magnifier inset in
the larger lens. More than 90 percent of Carson’s magnifiers are made using acrylic lenses.
A fresnel magnifier (pronounced “fre-nel”) is a flat magnifier that is produced by stamping a series
of annular optical grooves on to a flat sheet of acrylic or PVC. Fresnel magnifiers use far less
material than a typical double-convex magnifier lens, so they are typically very light and thin. The
“flat” profile of a fresnel lens makes them ideal for a purse or a wallet. Another added benefit of
a fresnel magnifier is the size of the actual lens. There are very few size constraints in producing
fresnel magnifiers than with other lens configurations. Hence, fresnel magnifiers can be made in
page-size or larger. One disadvantage of fresnel magnifiers is the “sharpness” of the image. Fresnel
magnifiers generally cannot produce as sharp an image as a double-convex magnifier lens.
What is a Linen Tester?
A linen tester, often referred to as a “thread counter” is most commonly know for its association
with the garment trade. Historically, linen testers were used to count the number of threads within
a fixed area of fabric. Linen testers have a measuring scale on their base, and they typically fold
flat for storage. Today, they are used in the printing industry to see how inks lay on a printed
surface. Linen testers are sold in varying magnifications or optical configurations.
Is a Magnifier with the highest power the best for me?
Not necessarily, the higher the magnification the shorter the focal distance. So in order to use a
high-powered magnifier, you would need to put your head very close to the object you are viewing. In
addition, a magnifier that is too powerful will distort the image making it difficult to read.
Lastly, a high-powered magnifier has a very small viewing area. If you have too high a
magnification, it becomes difficult to use the Magnifier as you end up focusing on too small a part
in the page. Don’t get too caught up with magnification. Regretfully we are in an industry where
some companies exaggerate magnification. Buyer beware!
What types of Magnifiers are best for Needlepoint?
Carson manufactures a number of hands free magnifiers for crafting and needlepoint. They are often
referred to as “around-the-neck” Magnifiers because they are positioned just below the chest of the
user and suspended by a cord around the user’s neck. These “around-the-neck” magnifiers provide the
user with free use of both hands, which is ideal for needlepoint. Caron’s LumiCraft (model LC-15),
MagniFree (model HF-25) and MagniShine (model HF-66), are all examples of “Around-the-Neck”
Magnifiers. Visit Carson’s Hands Free Magnifier section.
Another type of Magnifier that is designed largely for crafts is the MagniCraft Magnifier (model
MC-10). The MagniCraft has magnets that are embedded into this Bar Magnifier. This works very well
for needlepoint patterns. The user can place the pattern on a metal stand. The Bar Magnifier’s
magnets will hold the pattern in place, and Magnify the appropriate line on the pattern. Visit the
Sheet and Bar Magnifier section of this website to see all of our Carson’s Bar Magnifiers.
What things should I consider when purchasing a Lighted Magnifier?
Lighted magnifiers come in a wide variety of styles and shapes. The most important consideration when
purchasing a lighted magnifier is the type of lighting. Lighted magnifiers come in LED and
incandescent styles. Generally speaking a lighted magnifier with an incandescent bulb will be less
expensive than an LED lighted magnifier. However, LED magnifiers are generally brighter and use far
less power than an incandescent bulb. When you consider the cost of batteries, LED magnifiers are
typically a cost-effective investment.
In recent years, magnifiers have shrunk in size. LED Magnifiers are often powered by button-cell
batteries, thus allowing for sleeker and more compact designs. Products that include Carson’s
Lighted Rimless Magnifier and our Lighted MagRx could never have been made with out the use of LED
What are the advantages of Glass Magnifying lenses?
Glass magnifiers allow very high light transmission, which provides a very clear, precise image.
Glass magnifiers are also durable and extremely difficult to scratch. There are many grades of glass
available, however the best grade of glass magnifying lenses is better than the best grade of
acrylic lenses. Glass magnifiers typically magnify slightly more than acrylic magnifiers as a result
of the material density. The most popular glass magnifier from Carson is the SG-10 SureGrip
Glass magnifiers have declined in popularity over the years. Twenty years ago, nearly all the
magnifiers sold in the US were made from glass. Today, however, more than 90% of the magnifiers sold
in the US are made from acrylic.
What type of Binoculars are best for Hunting?
Some informal industry surveys suggest that 40% of all binoculars that are sold in the USA are
sold to hunters. The most popular style of binoculars sold are 10x42mm. What is so special about
10x42mm binoculars? Deer are most active at dawn or dusk, so brightness is critical. Full-sized
10x42mm binoculars gather more light than their compact counterparts, so 10x42mm Binoculars are
an obvious choice. They are ideal for hunting because of their superior light gathering
What type of Binoculars are best for Bird Watching?
8x42mm binoculars are the most popular optical configuration for bird watching. A 42mm objective
lens provides sufficient light gathering capabilities in low light conditions. And an 8x
magnification, allows the user to “steady” the binoculars much more readily than with higher
powers, making the task of bird-identification a little easier. Look for 8x42mm binoculars with
high light transmission capabilities like the 3D/ED’s.
What steps can I take to maintain my Binoculars?
Make sure your lenses are clean at all times and keep them free of fingerprints, dirt and debris.
Use a Stuff-it microfiber lens cloth or a C6 Lens Cleaner to clean your lenses quickly and
safely. Never use chemical on your lenses, it can harm the optical coating. When not in use,
always replace the lens caps and store your binoculars in a case. For more cleaning options,
visit the Lens and Screen Care product section.
What is Binocular eye relief?
Eye relief is the distance, in millimeters, a binocular can be held away from the eye and still
see the entire field of view. If you wear glasses, a longer eye relief would be advantageous
since your eyes cannot get as close to the eyepiece.
How do I focus my Binoculars properly?
There are several steps you should take to focus your binoculars. The first step is to close your
right eye and look through the left side of the binocular. Turn the center focusing wheel until
you have a sharp image. Then close your left eye and look through the right side. Turn the
diopter eyepiece until you have a sharp image in that eye. Lastly, look through both eyepieces
and use only the center focusing wheel when looking at objects at different distances. Now you
are ready to fully enjoy your Binoculars.
What is the purpose of Binocular lens coatings?
All the optical components of Binoculars (lenses, and prisms) should be coated to minimize light
loss and reflection problems inside the Binocular. A poorly coated Binocular can lose up to 50%
of the light initially gathered through the objective lens, resulting in a poor quality image.
By coating the optical components with a fine film of certain chemicals, light loss can be
greatly decreased. The highest quality binoculars have multiple coatings on all the optical
components. These are known as “fully multi-coated” binoculars. These Binoculars have the least
loss of light and the result is a higher quality image.
Does the type of prism used in Binoculars make a difference?
There are prisms located inside binoculars that function to flip an inverted image upright. There
are two common styles of prisms used in binoculars; the BK-7 and the BAK-4. The BAK-4 prism is
made of a higher density glass and can produce sharper images than a BK-7 prism can. If you are
unsure as to which prism is being used, hold the binoculars out in front of you and look through
the eyepiece. If you see a square shaped beam of light, chances are a BK-7 prism is being used.
A round beam of light indicates the use of a BAK-4 prism.
What is the importance of a Binoculars field-of-view?
The field of view is the size of the area that can be viewed through the binoculars. Field of
view is measured in two ways; angular field of view and linear field of view. The angular field
of view of a binocular is measured in degrees. Linear field of view is the width of area, in
feet, visible at one thousand yards. Remember that the higher the power of your binocular, the
smaller the field of view will be. In most cases, the larger the field of view, the poorer the
image clarity becomes, especially around the edges. Bear this in mind when making your choice.
Bigger does not always mean better!
Does Binocular lens size make a difference?
The amount of light passing through the different lenses of the binocular depends on the diameter
of those lenses. The objective lenses are located at the front of the binocular. The diameter of
the objective lenses are measured in millimeters. An 8x21mm Binocular has an objective lens
diameter of 21 millimeters. The larger the diameter of the lens, the more light they will
gather. More light means a brighter image of greater detail and clarity. The size of the
binocular exit pupil also affects the brightness of an image. The exit pupil is the diameter of
the beam of light, in millimeters, that passes through the eyepieces (oculars) of the binocular.
The larger the exit pupil, the brighter the binocular image becomes. Keep in mind however that
larger binocular lenses mean larger binoculars.
Which Binoculars are best for me?
There are many factors to consider in choosing the right binocular for an individual’s need. For
some it might be choosing the lowest price, color, or style. The most important factor in this
decision relates to how you intend to use the binoculars. To most people, binoculars are a
simple optical device but in reality they are complex, precision optical instruments.
What is the best Binocular magnification for me?
The magnification of a binocular is how many times closer an object appears than when viewed by
the naked eye. An 8x21mm binocular magnifies the image to eight times its normal size. Typical
binocular magnifications range from powers of 7x to 10x, however they are available in much
higher magnifications as well. Keep in mind, that as you increase Binocular power, less light
will be gathered, and the viewing field will be reduced as well. It is also very difficult to
keep an image steady at very high magnifications using a handheld binocular. A tripod is usually
necessary to steady an image at higher magnifications.
What type of Binoculars are best for Sporting Events?
This age-old question really comes down to personal preference. Do you want to carry heavy bulky
binoculars from your car to the stadium? Do you prefer the added brightness that a full-sized
binocular will offer? Or is the convenience of putting the binoculars in your jacket pocket more
important to you? The jury is split between full-sized binocular “brightness”, and compact
binocular “portability.” Whether you choose compact binoculars, or full-sized binoculars, there
are a few other factors to consider. If you are watching a fast-moving sporting event, do not
opt for binoculars that are too powerful (8x magnification is ideal). Higher magnification means
a smaller field of view (it will be harder to follow the action). Also, make certain that the
optical configuration of the binoculars offers a sufficiently wide field of view. Keep in mind,
however, that you may sacrifice binocular edge definition or binocular eye relief with a wide
field of view. In conclusion, it important to compare every feature.
What do I look for in Kid’s Binoculars?
A kid’s binocular should be durable and lightweight and aid in exploration and outdoor fun. The Hawk
fits all these criteria.
My child is fascinated with bugs, any recommendations?
It is important to encourage outdoor play in children that are fascinated with bugs. Carson Optical
has a variety of products to satisfy your child’s fascination. The BugView will allow your child to
catch bugs, examine them and release them when done.
What is best for a Kid’s Magnifier?
It is important to keep a few items in mind when looking for a kid’s magnifier. The magnifier should
have a large viewing lens yet still be lightweight enough for a child’s use. The BigEye is ideal for
kid’s because it has an oversized acrylic lens which makes it lightweight and is safer than glass.
How does Carson list magnification for a digital microscope?
Carson list the magnification as the total effective magnification based upon a 21″ monitor. To calculate the
effective magnification when the image is displayed on your monitor, multiple the screen size by the factor
listed on the product page for that digital microscope. Please note the effective magnification is a
combination of the optical system and a high powered digital zoom.
What is the resolution of the digital microscope?
Please check each product page, but please note there may be two resolution specifications, for
picture mode and for video mode.
My digital microscope doesn’t reach the listed resolution on the product page,
what can I do?
To achieve the maximum resolution in picture mode, in the software, make sure you go to
settings and select the maximum resolution. The software initially defaults to a lower
resolution. Also, please note the video resolution may be lower than the picture resolution.
I need software for my digital microscope, where can I download?
Please visit the Software Download page https://carson.com/customer-support/software/
Do the digital microscopes work with tablets or phones?
No, those devices are not supported.
Are all LED’s created the same?
LED’s are not all created equally. In general, more LED’s create more light. However, it is certainly possible
that a single well-constructed LED can outshine a group of poor quality LED’s. LED’s vary considerably in terms
of brightness, color and lifespan. Since there is no real industry standard to test LED’s, Carson generally
tests them ourselves. We compare LED’s from many manufacturing facilities before constructing our Reading
Lights. We test for brightness, durability and lifespan. We then select the lights that will create the best
value for our customers.
What features should I look for in a Reading Light?
There are several features to consider when purchasing an LED reading light. Some of the factors are clearly
visible in the package, and others are not. Below you will find details on most of the important considerations
when making your reading light purchase. For more information on Carson LED reading lights please visit the
Reading Light section.
Which should I buy, an LED or incandescent Reading Light?
LED reading lights generally cost a little more than incandescent reading lights but LED reading lights are well
worth the investment. LED reading lights last long, on average about fifty times longer than the bulb of an
incandescent reading light. LED lights are resistant to shock, where incandescent reading lights can break
easily. The most important consideration is energy use, LED reading lights use very little battery power and
operate at a low temperature. Incandescent reading lights consume a great deal of battery power, and thus are
much more expensive to operate than LED reading lights.