|
Welcome to Respect Products
|
A Buyers Guide to Flatbed Scanners
Expert Article By: Microtek Lab Inc
A Buyer's Guide to Flatbed Scanners
Flatbed scanners generally deliver the best combination of quality, flexibility, and usability in scanning. They can be used to scan different kinds of media, including photos and film (with the additional use of a transparency adapter); they can be used to scan text for OCR and document archiving; and they can be used to scan material of varying sizes and thicknesses - from small postage stamps to large mechanical blueprints and 3D objects. To determine the flatbed scanner for your needs, this buying guide covers some of the more important flatbed scanner specifications that you will need to know.
Bit depth and color pass
Practically all scanners today are single-pass types with 48-bit color. Gone are the scanners of yore that required three passes to capture the full RGB (red, green, blue) color information from an image in individual, painstakingly slow takes. Gone too are 24-bit and 36-bit scanners that proved sufficient in the past for delivering up to 68.7 billions of color.
Today's single-pass, 48-bit scanners are fast and can theoretically capture up to 250 trillion colors - clearly more color than the human eye can distinguish or what monitors and printers can reproduce - but impressive nonetheless for the promise of yielding hues as close to life as possible and delivering smoother color gradations. Ignore all but single-pass scanners when shopping for a flatbed, and aim for 48-bit color as well. Consider lower-bit models (such as 42-bits) only if your scanner of choice has other specs that a higher-bit counterpart may not have - such as patented technologies and special features - that more than compensate for the lower bit depth of your selected model.
Resolution
The resolution of a scanner determines the level of detail that can be captured; the higher the resolution, the sharper the scan will be. There are two types of resolution: optical and interpolated, with optical resolution being the more important spec, as it relates to the scanner's actual optics and amount of information that it can sample. The interpolated resolution of a scanner is helpful only in specific applications - such as scanning line art, where higher resolutions can even out jaggedness and produce smoother contours.
Most flatbeds today feature respectable specs for optical resolution, ranging from 2400 dpi to 4800 dpi. Any scanner with such resolution figures would prove a respectable choice, since these specs are more than capable of delivering sharp detail or enlarging images for most print applications. Remember, too, that scanning your images in the full resolution of the scanner is likely to yield file sizes of unmanageable proportions - without delivery any discernible benefit towards increasing image clarity or quality. So forget the resolution wars of the past when manufacturers trotted out their resolution specs to trump their closest rival. Instead, look for other features today in flatbeds that may be more important for your needs, or consider the resolution spec TOGETHER with these other features when choosing your choice of flatbed.
CCD vs. CIS Sensor Technology
Image sensors in flatbed scanners can be of two types - CCD or CIS. Scanners with CCD (charge-coupled device) sensors use a system of mirrors and lenses for redirecting light reflected from the original document to the CCD array. Because of the required optics, CCD scanners are more expensive to produce and result in bulkier scanners, compared to their CIS counterparts. The image quality produced by CCD scanners, however, is far superior to that produced by CIS scanners.
CIS, or Contact Image Sensor technology, is a more recent development in which the sensor array lies just under the scanner bed, so that the sensors catch reflected light directly. Since CIS scanners do not need a complex optical system, they are cheaper to produce and are smaller in size, resulting in portable, lightweight models that may be prove ideal for cramped desktops. CIS sensors also contain on-board logic that consumes less power than CCD. But because the on-board logic utilizes space that would normally be used for the mirrors and lenses in a CCD to sense light, scans from a CIS scanner are lower in quality. As a result, most people tend to forego the slight savings that can be obtained from a CIS scanner in favor of getting higher-quality CCD models instead.
Connectivity & Interface
Most consumer-level scanners today will feature USB ports - either Hi-Speed USB (USB 2.0) on more recent models, or the earlier USB 1.1 standard. Hi-Speed USB is backwards compatible with the USB 1.1 and has a data transfer rate of 480 megabits per second (Mbps). Higher-end scanner models are likely to include the FireWire interface as well, allowing scanners to be used in advanced, professional such as audio/video transfer and data storage. Scanners with either USB or FireWire interface are hot swappable - which means the scanners can be plugged or unplugged from other devices to which they are connected without having to turn the scanners off and on. Older scanners will include SCSI or parallel ports, but you shouldn't have to consider these legacy-type models - unless you are using the scanner to connect to older computers. When shopping for a flatbed, any scanner with a Hi-Speed USB port should be purchase-worthy, but consider getting a model with dual Hi-Speed USB and FireWire interfaces to expand your range of possible connections to many other devices and peripherals.
Scan Speed
Speed specifications in flatbeds are hard to determine - unless the scanner manufacturer provides the specs or the exact conditions in which material is scanned. Scan speeds can run from seconds to several minutes, depending on a wide variety of factors. For instance, to compare scan speed between two comparable models, one will need to know the size of the material being scanned, the resolution setting, the interface being used, and the processing speed and power of the computer to which the scanner is connected. Check speed claims carefully if these are made at all; it may help to do an actual or sample scan with the model of your choice, and see if you are satisfied with the speeds of the preview and actual scans. You could also check to see if your flatbed model has been reviewed in computer magazines or sites and rated for speed, as benchmark tests may give a more comprehensive picture on how fast the scanner runs.
Size of Scan Bed
Most flatbeds today will start out with a standard scan bed size of 8.5" x 11.7", approximating the dimensions of a letter-size image or document. From there, various bed-size configurations could come into play, including 8.5" x 14" to accommodate legal-size material, and 12" x 17" for large, tabloid-size scanning. It's usually a good idea to consider a flatbed with a bed size that's beyond the bare minimum - in this case, larger than the barebones 8.5" x 11.7". Not only can you fit larger-sized material onto the scan bed, you can also group several smaller pieces on the scan bed and perform batch scans (scanning in groups) to save time and effort. Dynamic Range
The dynamic range of a scanner measures how well it can capture the tonal range of an image, ranging from the brightest highlights to the darkest shadows. Dynamic range is measured on a scale from 0.0 (perfect white) to 4.0 (perfect black), and the single number associated with a scanner indicates how much of that range it can tell apart. The minimum and maximum density values that can be captured by a scanner are called Dmin and Dmax, respectively. If a scanner's Dmin was 0.2 and its Dmax was 3.0, then its dynamic range would be 2.8.
While dynamic range is a term often bandied about, in truth the spec is more important for film scanners used to scan slides, negatives, and transparencies - as these types of media have a broader range of tones compared to photos, and for which a scanner's higher dynamic range can make a difference. Most flatbed scanners will have a dynamic range of 2.8 to 3.0, but don't be surprised if you can't find it in the specs, as this is not critical information needed by the average user looking to scan photos or prints.
Software
In selecting the scanner of your choice, consider the software that comes with it. Software will always include the scanner's own driver or scanning software, as well as a host of complementary programs such as image-editing software like Adobe Photoshop to which the scanned image is delivered; optical character recognition software like ABBYY FineReader Sprint for text scanning and OCR; color calibration software for higher-end scanner models; and even photo-repair software like DIGITAL ICE. Check for extras as well, such as proprietary or exclusive technologies.
|
About The Author
Microtek Lab Inc. is a consumer electronics company focused on scanners, plasma and lcd televisions, digital projectors, lcd monitors, digital cameras, home theatre equipment, and accessories. You can view their online store at http://www.store.microtek.com Use of this article is permitted provided that the article is used in its entirety.
|
|
Sponsors:
A Buyers Guide To Flatbed Scanners News
Couldn't open rss feed in /A-Buyers-Guide-to-Flatbed-Scanners.php
Open Question: Events i. houston tx free stuff ?
Hi I'm not looking for donation or good banks I'm looking for fun on the weekend like event were its fun on the weekend they have games free food in Houston Texas is their a website out their were I can go to to look j already tried Google j type in free event in Houston didn't find anything I'm just looking for fun free think in Houston for me and my boyfriend to do outdoors pls help thank you so much for your time also me and my boyfriend don't like to sit at home on a saturtday not doing anything we will like to Ho out to event that are free in Houston so if anybody know a website that has a list or no any pls respond
Find more...
Open Question: Yes. No job to big, I need a job! now!?
I can work at night time or day time,
I can work in doors or outdoors, with or with out a tie. night porter is good for me.
or dish wash,
or restaurant works I can do it all.
not home I'm working! not! yet!
I know how to clean house i did that with my mom before. work for less then you pay anyone else. and I can mow however I have an electric mower so we can work with that one or no?
I can even work for FOOD! YES! don't feed the troll. feed me. or don't feed me! feed the troll.
Can L*ck that off the ground for $20. or what ever! YES!
I can dance all night for a free ride to the dance and dance with your alone/only. YEAH!
Can Dance alone all night long! YES! if that is what it takes to make $1.
CAn teach anyone how to get punched. or how to walk away! just say no!
Can try to teach you to just say no to drugs! 1000 easy steps.
I can walk your dog for $1. a day? or less what ever you want oh?
house set I can do that one! I did that 1 for folks before!
Find more...
Resolved Question: Marbles Mountain Man Bowie or Colt .45 Bowie. Which is the better knife?
http://www.smkw.com/webapp/eCommerce/products/Colt%26reg%3B/Colt%C2%AE+.45+Bowie+with+Leather+Belt+Sheath+and+Sharpening+Stone/CT30645S.html
http://www.smkw.com/webapp/eCommerce/products/Marble%26%23146%3Bs+Outdoors%C2%AE/Marble's%C2%AE+Mountain+Man+Bowie+with+Stag+Handle/MR234.html
Find more...
Open Question: What is the best to lay on when tanning outdoors?
I want to know what is the best thing to lay on when I am tanning outside to help me get a better tan quicker. Please don't tell me about the risk of tanning because I already know. Also it is warm here so I am not crazy. Anyway, I heard a trampoline was a good idea but mine...blew away... so that's not an option lol. Thanks!
Find more...
Resolved Question: Someone help re-word and edit?
Definition:
Albinism is a hereditary condition present at birth. It is characterized by a lack of pigment that normally gives u to the skin, hair, and eyes. Various types of albinism exist, all of which involve lack of pigment in varying degrees. The condition, which is found in all races, may be accompanied by eye problems and may lead to skin cancer later in life.
Description:
Albinism is a uncommon disorder found in. There are 10 types of the most common form of the condition, known as "oculocutaneous albinism," which affects the eyes, hair, and skin. In its most severe form, hair and skin remain pure white throughout life. People with a less severe form are born with white hair and skin, which turn slightly darker as they age. Everyone with oculocutaneous albinism experiences abnormal flickering eye movements (nystagmus) and sensitivity to bright light. There may be other eye problems as well, including poor vision and crossed or "lazy" eyes (strabismus).
The second most common type of the condition is known as "ocular" albinism, in which only the eyes lack colour; skin and hair are normal. There are five forms of ocular albinism; some types cause more problems-especially eye problems-than others.
Diagnosis:
It's not always easy to diagnose the exact type of albinism a person has; there are two tests available that can identify only two types of the condition. Recently, a blood test has been developed that can identify carriers of the gene for some types of albinism; a similar test during amniocentesis can diagnose some types of albinism in an unborn child. A chorionic villus sampling test during the fifth week of pregnancy may also reveal some types of albinism.
The specific type of albinism a person has can be determined by taking a good family history and examining the patient and several close relatives.
The "hairbulb pigmentation test" is used to identify carriers by incubating a piece of the person's hair in a solution of tyrosine, a substance in food which the body uses to make melanin. If the hair turns dark, it means the hair is making melanin (a "positive" test); light hair means there is no melanin. This test is the source of the names of two types of albinism: "ty-pos" and "ty-neg."
The tyrosinase test is more precise than the hairbulb pigmentation test. It measures the rate at which hair converts tyrosine into another chemical (DOPA), which is then made into pigment. The hair converts tyrosine with the help of a substance called "tyrosinase." In some types of albinism, tyrosinase doesn't do its job, and melanin production breaks down.
Treatment:
There is no treatment that can replace the lack of melanin that causes the symptoms of albinism. Doctors can only treat, not cure, the eye problems that often accompany the lack of skin color. Glasses are usually needed and can be tinted to ease pain from too much sunlight. There is no cure for involuntary eye movements (nystagmus), and treatments for focusing problems (surgery or contact lenses) are not effective in all cases.
Prognosis:
People with this condition can expect to have a normal lifespan. People with albinism may experience some social problems because of a lack of understanding on the part of others. When a member of a normally dark-skinned ethnic group has albinism, he or she may face some very complex social challenges.
One of the greatest health hazards for people with albinism is excessive exposure to sun without protection, which could lead to skin cancer. Wearing opaque clothes and sunscreen rated SPF 20, people with albinism can safely work and play outdoors safely even during the summer.
Find more...
Open Question: Dog barking at night?
I have a chihuahua who recently started barking half the night. She is not locked up during the day or anything actually we live on a farm so she is outdoors most of the day with one of us, her diet hasnt changed, the location she sleeps in her kennel hasnt changed, she isnt actling like she dont feel good or hurts. Its odd she has never done this before anf the past 3 weeks its everynight. Yelling at her, letting her outdoors, chew bones nothing works. How and what can I do. I cant function on the 2-3 hours of sleep. ..... For example we put her to bed when we go to bed between 10pm and 12 and 20-30 minutes later she srarts barking, you yell at her or smack her kennel and she will stop for 20-30 minutes and start barking again. Repeat that all night long.
Find more...
Open Question: Doing track for the first time? Tips?
I'm a senior and I'm doing track for the first time, it starts this monday. I had never been a runner before and I started in Novermber with a 12 minute mile. Eh. I worked at it, and now I'm better and I run a 7 minute mile indoors and a 8-9 minute outdoors. Today I went to the actual track and ran a mile and did terrible. I came in at 10 minutes which is no good for competition. I feel bad now, I don't want to be a disgrace to my team :/ I don't want to look like a fool when all the other girls are running 7 and 6 minute miles. I don't know why I did so bad today, Now I'm so worried. I know I can run relays but I kinda wanted to be able to do the one mile. I don't know. I'm not that familiar with track so I don't know too much. My 100 sprint is 15 sec. Our fastest girl in 13 sec. I want to be able to beat people and I feel bad that I can't. I don't want to be a dissapointment. Is there anything I can do to improve my time some over the next couple weeks? Tips. I cramp up real bad thats why I don't go too fast. Any tips would be helpful. Thanks in advance.
Find more...
Open Question: Is this a good Rhyming poem?
Is this a good poem if not then please send me one that has abab or abcabc or aabb anything but please be at least 8 lines. A rhyming poem is a poem that has lines or words that end with the same sound. Okay here is the poem....
Summer Pleasures
Sunshine beaming golden heat
For lots of fun outdoors;
Vacations, for a sweet retreat
To mountains, plains and shores.
Kids in constant summer motion,
Free from teacher’s rule,
Head to toe in suntan lotion,
At the beach or pool.
Inflatable rafts on which to float,
Camping and fishing gear,
Rowing or sailing or waterski boat,
Tell us summer’s here.
Things we can’t do the rest of the year
Are summer’s special treasures;
Oh summer, summer, linger long,
And give us all your pleasures!
Find more...
Open Question: I need a good cat shelter in south east london?!?
I have 4 cats all together, due to one cat having kittens (not out of choice!). To be honest, we dont have the time or money to look after all 4, so we decided on giving away the two (now fully grown) kittens. They are both 2 years old in june, but need some tlc that we just cant afford. One has long hair that gets so matted in winter, its uncontrollable, the cat wont let us brush him let alone try to cut the matts and its £100 to take him to a salon, which is unaffordable im afraid. The other, spends a lot of time outdoors, so we rarely see him but he's just another mouth to feed. We're not set on giving them away yet, but they're causing so much trouble due to them being males and spraying around the house, that we're constantly spending money on special sprays and disinfectant. Is there any cat shelters local to south-east london that are extremely good, or even someone who's willing to personally take them?
I want to be prepared in case my mum does decide on giving them away! thankyou!
Find more...
Open Question: what wood types are good for outdoors?
I am making a dog house for my design and technology and i need good wood that wont weather in the rain
Find more...
|
|
|
|
