Buying a wide format scanner

You may have some questions about buying a wide format scanner. We did!

The information below is largely based on our experience of buying, using and ultimately selling large format scanners for use in CAD applications.

Do I really need to buy a large format scanner?
Who are the main large format scanner manufacturers for CAD?
Which scanner models should I consider?
What should I look for in a scanner?

• Paper Feed
• Imaging System
• Colour Capability
• Scan Width
• Scan Thickness
• Resolution
• Scan Speed
• Accuracy
• Scan Quality
• Upgradeability
• Energy Star Compliance
• System Requirements
• Networkability
• Weight and Dimensions
• Floorstand
• Scanning Software
• Warranty

Disclaimer

Do I really need to buy a large format scanner?

The cost of wide format scanners has fallen BUT do you really need one?

How many scans will you do in one, two and three years? Can you really justify buying a large format scanner based on these volumes?

If you need a scanner but cost is an issue, why not lease a scanner?

Finally, consider the used equipment market. There's a lot of good but older generation kit around.

Who are the main large format scanner manufacturers for CAD?

Colortrac - www.colortrac.com

(Branded under imagePRO by Paradigm and sold by Canon.)

Colortrac is an innovative British wide format scanner headquartered in St Ives, near Cambridge, England. It was founded in 1989 to develop digital large format scanning solutions for the oil exploration industry and was a pioneer in colour scanning.

Colortrac made notable technical breakthroughs in the development of expensive wide format scanners for the specialist reprographics market but remained largely unknown despite winning a Queen's Award for Export Achievement and acquiring the well-known ANAtech (US) brand in 1999.

Colortrac's fortunes have changed in recent years. Its break came when it identified an opportunity among cost-conscious professionals at the low end of the market for affordable large format scanners. The release of aggressively priced SmartLF 4080 series of CIS-based range in June 2004 made Colortrac the fastest growing large format scanner manufacturer in 2005.

In February 2006, Colortrac announced the replacement of the popular 4080 with the new and much improved SmartLF Cx 40 CIS range. While the Cx 40 raised the technical bar, it retained the same aggressive price as the old 4080 series.

In September 2006, Colortrac upped the ante among traditional CCD-based wide format scanners with the introduction of the innovative 1200 x 600 dpi optical resolution SmartLF Gx 42 series.

In October 2008, Colortrac announced yet another new CIS-based scanner, the SmartLF Ci 40, a unique device based on solid roller technology used by ANAtech in the 1990s. This "back to the future" approach, re-purposing proven mechanical design concepts with the latest CIS sensor and digital electronics, confirms Colortrac's reputation as a leading wide format scanner innovator.

During 2008 Colortrac invested heavily in new employees and QA processes with the specific aim of improving the overall level of quality in the finished product. Qualified staff with years of industry experience have been employed in both the UK factory and in its manufacturing plant in Suzhou, PR China, to run and maintain Colortrac's voluntary QA and ISO production programs.

During 2009, Colortrac have replaced their Gx CCD series with the Gx+ series, which includes the world's widest sheet-fed scanner - the Gx+ 56. Like the Image Access WideTEK series, the Gx+ series uses white LED illumination instead of traditional flourescent tubes. This has environmental and energy benefits and reduces scanner warm-up time.

Contex - www.contex.com

(Also branded under GTCO/Calcomp, HP, IDEAL, Océ and Vidar.)

Contex Scanning Technology are a Danish company who introduced their first monochrome (black and white) scanner in 1988. Today they are the leading manufacturer of large format scanners and scanning software for both colour and monochrome scanning solutions in the world.

Contex wide format scanners are also branded as GTCO/Calcomp, HP, IDEAL, Océ and Vidar. With some justification, Contex described themselves as "the most dominant solution in wide format scanning" and once claimed to have "control of 92% of the wide format market". However, in recent times Contex's CCD-only product line placed it under great pressure from its competitors.

Contex's extensive product range was based exclusively on traditional CCD technology. CCD scanners use cameras, mirrors and fluorescent tubes, making them expensive to build and buy and best suited to scanning colour artwork. While they only had a CCD product range, Contex spent time and energy dismissing CIS-based scanners as unsuited for every application. At the same time, it defended its low resolution Hawk-Eye scanner as suitable for CAD.

It was clear to many that the industry leader had lost its way. With Graphtec and Colortrac CIS scanners clearly showing that CIS technology was more than able to provide the quality needed for scans of technical documents, the biggest market for wide format scanners, Contex began to lose market share.

In April 2008, new management at Contex responded by upgrading their CCD-based product line to the new, more competitive HD Series with true 600 dpi optical resolution. In June 2008, Contex bowed to the inevitable and introduced its first generation CIS-based scanners, the SD Series. This has an impressive specification that includes the first true 1200 dpi optical resolution in any scanner and has been followed in September 2009 by the A1 / D size XD2490. With Colortrac, Contex is now the only provider of both CCD and CIS-based large format imaging solutions.

In July 2008, in a move intended to strengthen Contex's American distribution channel, Contex acquired IDEAL, its largest US-based distributor. In today's competitive market, Contex remain a force to be reckoned with.

Graphtec - www.graphteccorp.com

(Also branded under KIP and under Quatra by Paradigm.)

Founded in 1949, Graphtec Corporation, Yokohama, Japan, is a respected industry leader in cutting plotters, flatbed cutters, wide format scanners, digital data acquisition and test instruments.

Graphtec corporate philosophy emphasises the pride employees must take in the company's products. This is seen in the superb engineering quality of their scanners. Unlike Colortrac and Contex who invest in both CIS and CCD optical imaging technologies, Graphtec is committed to CIS-based large format scanners only.

Unsurprisingly, as the manufacturer of only one kind of scanner, Graphtec believe that CIS imaging is best for scanning both wide format technical drawings and graphics. While many disagree that CIS is the best technology for capturing the high colour gamut of graphics artwork, the quality of Graphtec's colour CIS scans is impressive enough to challenge this belief.

Graphtec scanners are not cheap. When Graphtec first introduced their CIS scanners in 2002 they did so on the basis that CIS was superior to CCD and that therefore Graphtec CIS scanners deserved the equivalent high prices of their CCD-based rivals. Colortrac's success with the SmartLF range of much more affordable CIS scanners quickly eroded Graphtec's advantage.

In January 2007, in an effort to get into the lower end of the market, Graphtec introduced the low cost SP200W Scan Print system. This now redundant device showed muddled thinking: While it included the excellent SK200 36" colour scanner, it could only print directly to the supplied (poor) Graphtec printer.

Nevertheless, Graphtec enjoyed success with the SK200 scanner in the OEM MFP market where it was ironically fitted to other printing systems such as the Paradigm EIS Supra MFP and the KIP3000. This success led Graphtec to further improve the SK200 and to release it as the standalone CSX 300 in April 2008. This scanner is attractively priced in the UK where it sells well to cost-conscious buyers. It costs much more in the US.

In April 2008, Graphtec released the HD-Plus Series of 42" CS610/510/IS210 scanners. In reality, these enjoyed just minor improvements over the previous series. There was nothing new or imaginative in this release. It remains to be seen if these expensive, proven but traditional CIS devices can continue to sell well in a changing CIS market which now has Contex as a major player.

Engineering and image quality are Graphtec's strengths. Their weaknesses are high prices and powerful but poor and awkward to use software. This has not stopped many from buying them.

Image Access - www.imageaccess.de

(Also branded under Infinity WF by Kodak.)

Founded in 1993, Germany's Image Access GmbH is the newest of the large format scanner manufacturers.

Image Access Computer GmbH was founded in 1993 by Thomas Ingendoh in Wuppertal, Germany, to produce graphics and scanner interface cards and components. One early product was a PCI HiSCAN scanner card which connected almost all scanners with a video interface.

In 1996, Image Access was developing hardware components for microfilm readers, copiers and scanners. In 1997, it introduced the Bookeye Planetary Scanner which revolutionised document capture in libraries, universities, museums, etc. Today the Bookeye product family is marketed worldwide by ImageWare Components in Bonn, Germany and in the USA by Image Access, Inc.

One technical milestone in Image Access' history was the development in 1997 of high-speed cameras and electronics for Agfa's Hybrid Scanner SC51 which scanned 240dpm, double-sided at 200 dpi. In 1998 Image Access began the development of grayscale and colour scanners and implemented several OEM solutions for grayscale scanning. A colour scanner with a throughput of 60+ dpm was completed in 1999. It was one of the fastest professional document colour scanners in the market.

In 2000 Image Access began development of radical, new Scan2Net (S2N) scanning technology. This technology sets Image Access apart, providing their scanners with the speed and networking which is their major benefit. Using S2N technology, devices are easily integrated into existing network structures. Operating system independent, an S2N device connects the scanner via a network cable to Unix, Macs or PCs and is run from a browser. It is a true network-ready scanner.

By 2003 this technology permitted the release of a Scan2Net A2 scanner under the new product name of WideTEK. Since then, Image Access has developed large format scanners that use S2N. CeBIT 2007 saw the debut of the WideTEK 36 while the WideTEK 42 and WideTEK 48 were announced at CeBIT 2008. Now, with improvements to its software functionality, the WideTEK range sells in growing numbers. Image Access announced the first duplex wide format scanner, the WideTEK 36 DS in September 2009.

German excellence in engineering makes the WideTEK one to watch! However, like a Mercedes Benz, it costs more than most want to pay. Despite being the first CCD technology scanner to offer ENERGY STAR compliance and LED illumination, it is not a solution for cost-conscious users wanting an everyday scanning solution for technical drawings. Image Access's WideTEK reserves its best for the graphics market.

Shapemakers - www.theshapemakers.com

Established in 1995 in Queensland, Australia, Shapemakers is the manufacturer of the most unique and most affordable large format desktop colour scanning system... the Deskan 6.

Designed by an accredited member of the Australian Design Institute and developed and refined over several years, the Deskan uses an A4 motorised scanner that moves down a specially calibrated guide to capture a wide format drawing in several strips. Each strip is saved, automatically corrected for distortion and joined by stitching software that recognises special control points. Because no moving part of the Deskan scanner comes into contact with the image it is truly suitable for scanning delicate or damaged media.

Popular worldwide, the Deskan has especially strong appeal in emerging countries where the need for a low to medium volume large format colour scanning solution at a fraction of the price of comparable conventional A0 and E-size scanners is paramount. One fast emerging market for the Deskan is among CNC companies wanting affordable and flexible wide format scanning. Deskan FastParts offers cutting businesses an affordable scan-to-vector DXF solution that can be used to reverse engineer parts quickly and cost-effectively for accurate reproduction.

Shapemakers is Brisbane's oldest and most respected wholesale sign service bureau specialising in the manufacture of quality custom-made products for the sign industry. Shapemakers' routers, machining centers and laser cutting equipment can complete almost any type of CNC and cutting job. Shapemakers is also the manufacturer of Pictobraille (Building Code of Australia Compliant Braille and tactile signage products), Tactile Ground Surface Indicators, Stair Nosing and a distributor of Scan2CAD raster to vector conversion software.

Widecom - www.widecom.com

The 1990s were the heyday of the Widecom Group, a relatively successful Indo-Canadian manufacturer who established a public limited company in Canada in 1991. Despite largely shutting up shop in 2003, they have a web site that creates the appearance that they still trade. It appears not to have been updated since 2003.

Widecom were a pioneer of CIS (contact image sensor) technology manufacturing proprietary SLC (Single Line Contact) technology large format scanners from 1992. Today, CIS optical image sensing technology is the technical drawing scanning standard which has replaced traditional CCD (charge coupled device) scanners using cameras and mirrors. Widecom influenced CIS's development but failed to profit from it.

During the mid-90s Widecom introduced several "firsts", like their Image Database File Management System for distributing large format engineering documents across the Internet. This was followed with what they claimed was the "World's Fastest Large Document Scanner", the SLC1036C colour scanner and the "World's Widest Scanner", the 72" wide SLC972C colour scanner with an ability to scan up to 1/2-inch thick originals on foam board or cardboard. All impressive achievements.

Today Widecom's technology is long in the tooth compared to that of Colortrac, Contex, Graphtec and Image Access. Unlike these wide format scanner manufacturers who are a constant, reliable source of new large format scanners, Widecom has faded away to who knows where. It seems that they run a skeleton office to keep up appearances. This is not enough. On current specifications their products are uncompetitive. We question who would buy them now and, if they are still sold, who would support them?

On that basis, we cannot recommend Widecom scanners until they introduce new products. We do not include Widecom in our Large Format Scanner Comparison Chart and carry only limited technical and historical information on their products.

Which scanner models should I consider?

We've prepared a handy large format scanner comparison chart that lists over 55 different large format scanner models manufactured by Contex, Colortrac, Graphtec, Image Access and Shapemakers. For each model it shows the UK and US list price, floorstand price, scanning software price, type of paper feed, imaging system used, illumination used, colour capability, scan width, maximum media thickness, optical resolution, scan speed, accuracy, upgrade options, Energy Star compliance, connectivity, networkability, supported operating systems, weight, dimensions, supplied warranty details and country of manufacture for each model.

To receive your copy, click here.

What should I look for in a scanner?

Paper Feed

All large format scanners except the Shapemakers Deskan are sheet-fed. This means that you insert the drawing to be scanned into the front of the scanner. During scanning, the scanner's transport system pulls the drawing through the scanner to the back. The exception is the Colortrac Ci 40, where the drawing is fed around a large diameter roller and exits at the front.

Most sheet-fed scanners are face-down - i.e. the paper is fed into the scanner upside-down. However there is a growing trend for scanners to be face-up so you can see the document as it is being scanned.

The Shapemakers Deskan is different from all other scanners. The drawing to be scanned is placed on a flat surface. The scanner, which comprises an A4 / A size motorised scan head with guide, is placed over it. The drawing is then scanned in strips which are stitched together by the scanning software.

The benefits of the Deskan are that it is the least expensive large format scanning solution, is very transportable and is good for delicate drawings that can be damaged by a sheet-fed scanner's transport system. The disadvantage of the Deskan is that it is relatively slow to use.

Imaging System

There are two imaging systems used in large format scanners - CCD and CIS.

CCD is the traditional imaging system used in large format scanners and involves a combination of lenses, lights and mirrors.

Contex HD scanners use traditional CCD technology with flourescent lamps. Flourescent lamps have two disadvantages. First, they require a comparatively long warm-up time to stabalise and capture colours accurately. Second, they are classified and sold as consumables as they are expected to burn out and die after a period of usage. Image Access and Colortrac have got around the disadvantages of flourescent lamps by using bright white LEDs in their CCD scanners instead.

Colortrac SmartLF Cx and Ci scanners, Contex XD and SD scanners and Graphtec scanners use CIS technology. CIS scanners have no lenses, lights or mirrors, make greater use of digital electronics and use integrated RGB LEDs for illumination. This makes them cheaper to build, less heavy, more robust and means they can be used almost immediately after power-on.

Proponents of CCD technology will argue that CIS devices are not as good at scanning folded or wrinkled drawings as CCD scanners because their lower depth of focus means they cannot focus on bits of the drawing that are further away from the sensors. By the same token, feeding folded, wrinkled drawings through a CCD scanner is more likely to result in a stitching error, where parts of the drawing scanned by different cameras within the scanner do not line up! (See Large format scanner accuracy and calibration.)

CCD scanners normally have a wider colour gamut (range of colours) and a higher dynamic range (ability to "see" subtle shades without "blacking out" or "whiting out"), making them ideal for capturing artwork and photographs. However CIS scanners are ideal for CAD users with technical drawings, where capturing a wide range of colours or tonal ranges is unlikely to be an issue.

Colour Capability

Do you need colour or not?

Most CAD drawings are black and white. However, our experience is that most CAD users buy colour scanners because most CAD users expect to have to scan in colour at some stage.

If you have a colour requirement, CAD work does not warrant the use of a high performance, reprographics quality colour scanner. Any colour scanner in our large format scanner comparison chart is capable of providing colour scans suitable for CAD.

Large format scanners are offered with the following colour options:

• Monochrome (black and white, greyscale) only with no colour:

  Colortrac SmartLF m models
  Contex SD4410
  Graphtec IS210 Base and Pro

• Monochrome and 8-bit colour (256 colours) - more than enough for CAD:

  Graphtec IS210 Pro LC

• Monochrome and slow 24-bit colour (16.7 million colours).
• Monochrome and fast 24-bit colour (16.7 million colours).

Within any manufacturer's range, monochrome scanners cost less than colour ones. The faster the colour scanning speed, the more expensive the scanner.

Colortrac monochrome scanners can be upgraded to colour. In addition, most slow colour scanners can be upgraded to fast colour.

If you need colour but your colour volumes are low, get a slow colour scanner. There will be no improvement in scan quality when you buy a fast colour scanner. It just scans faster. Sometimes too fast! See Scan Speed, below.

A final note about colour: When reading about different scanners you'll find mention that some of them scan in 48-bit colour. What this means is that the scanner scans in over 281 trillion colours (48-bit mode) and then chooses the "best" 16.7 million colours (24-bit mode), which it saves. This is of absolutely zero importance for scanning technical drawings and should not be part of your consideration! Even if colour is important to you, 36-bit colour is more than enough to capture the entire tonal range it is possible to get in the medium capable of holding the widest range of colours (film transparencies).

Scan Width

The scanner you buy should have a scan width large enough to scan your drawings.

Most scanners have scan widths between 36" and 42". These can scan A0 / E size drawings in portrait (A0= 33x47", E=34x44", Arch E=36x48").

The Contex SD series has a scan width of 44" and can scan E size drawings in landscape.

The Image Access WideTEK 48 (48"), Contex HD5450 (54") and Colortrac SmartLF Gx+ 56 and T56 (56") are super-wide scanners that can scan both A0 and E size drawings in landscape.

If you only need to scan A1 / D size drawings (A1=24x33", D=22x34", Arch D=24x36"), look at a scanner such as the Graphtec CS510-06 (24"), the Contex XD2490 (24"), the Contex HD2530 (25") or the Colortrac Gx+ 28 series (28"). These scanners are too small to scan A0 / E size drawings but are large enough to scan an A1 / D size drawing in portrait.

Scan Thickness

What is the thickest size of paper or board you want to scan?

Most CAD users scanning technical drawings do not need to scan thick media like cardboard. Most CAD users will be exclusively scanning standard thickness paper sheets.

Most scanners are limited to scanning thin media, i.e. standard thickness paper sheets ranging from 0.012" (0.3 mm - the Colortrac Ci 40) to 0.1" (3 mm - the Image Access WideTEK range). 0.012" equates to a paper weight of approximately 270 gsm.

If you want to scan thick media, Contex HD and HP scanners accept media up to 0.6" (15mm) thick and the Shapemakers Deskan can scan media up to 0.8" (20mm) thick. Both Colortrac and Graphtec also produce scanner options that will accept media up to 0.8" thick (Colortrac Gx+ T and Graphtec CS610 series).

Resolution

There are two types of resolution, optical and interpolated.

Optical resolution is the only type of resolution that matters, as this is the resolution at which your drawings are actually scanned.

The optical resolution you need will depend on your drawings. In our experience 200 to 400 dpi is optimal for most CAD drawings. We recommend that you choose a large format scanner with an optical resolution of at least 400 dpi.

Interpolated resolution increases the scanned resolution of an image by calculating (making up!) new pixels to fill in between the scanned pixels. All it does is increase the size of the image without adding detail from the original drawing. It does NOT create a better quality image.

Large format scanner manufacturers and their representatives are often creative with scanner resolution descriptions:

• Until recently, Colortrac advertised their SmartLF Gx scanners as having 1200 dpi resolution. However although Gx scanners captured 1200 x 600 dpi, this was actually saved as 600 x 600 dpi.

  Colortrac have now released the Gx+ series. The Gx+ 28 and Gx+ 42 models have true 1200 x 1200 dpi and can be correctly described as having 1200 dpi resolution.

• Until recently, most Contex scanners had an optical resolution of 508 dpi but were described as having a "real" resolution (or even optical resolution, on some brochures) of 600 dpi. The Contex Puma, which had an optical resolution of 600 dpi, was described as having a "real" resolution of 800 dpi.

  With the release of their 600 dpi optical resolution HD scanners and 1200 dpi optical resolution XD and SD scanners, Contex are now describing their scanners' resolution correctly. However, there are still a lot of older Contex scanners on the market.

  Be aware that the advertised resolution of these older scanners might not be what it seems.

• Graphtec describe their scanners as having 600 dpi. However, Graphtec scanners only scan at 600 dpi when you scan using their High Quality mode.

  Graphtec Base models do not have a High Quality mode, therefore they cannot scan at 600 dpi.

• Some large format scanner distributors and resellers describe scanners using their interpolated resolution.

  If you see a scanner described as having "9600 dpi", this is definitely its interpolated resolution and NOT its optical resolution!

• The terms "enhanced resolution" and "extended resolution" are euphemisms for interpolated resolution.

• The term "maximum resolution" is shorthand for maximum interpolated resolution.

Scan Speed

Scanner manufacturers claim impressive scan speeds for their scanners, but all the manufacturers use different criteria to rate speed and use different conditions to measure it. You cannot compare one quoted speed against another to see which scanner is fastest. In fact, published scan speed figures are fairly meaningless.

First, the lower the resolution a drawing is scanned at, the faster a scanner will go. So Contex and Colortrac measure scan speed at 200 dpi to make their scanners look as fast as possible.

Contex try to disguise the fact that their scan speed is measured at 200 dpi by calling it 400 dpi Turbo. This means that the scanner is scanning at 400 dpi along the width of the drawing and at 200 dpi along its length. After scanning, the 200 dpi is interpolated back to 400 dpi. So, 400 dpi Turbo effectively means 200 dpi.

Second, a scanner can only scan as fast as the PC it is scanning to can receive and process the scanned data. During a scan you will often see a scanner pause as chunks of data are sent to the PC and processed. After the scan is finished, there may be a long wait time before the host PC becomes available again. This means that the speeds that scanners actually scan at can be considerably slower than published speeds.

If you spend extra money buying a fast colour scanner, be aware that it can be as slow as a slow colour scanner for all practical purposes. If the ability to scan in colour at high speed is a requirement then you MUST invest in a high performance PC as well.

The only scanners this does not apply to are Image Access WideTEK scanners, which are fundamentally different to other scanners. WideTEK scanners do all image processing within the scanner itself before sending the scan across the network via a 1Gb ethernet connection. In house speed tests between a WideTEK and "traditional" scanners have indicated that the WideTEK is considerably faster than other scanners, particularly when scanning large colour files. This was confirmed by BERTL, the American business equipment research and testing laboratory, who described the WideTEK 36 as the fastest scanner in the world.

Third, if you are scanning delicate drawings, you actually don't want them rattling through the scanner at high speed!

Fourth, workflow. How fast can you work with a fast scanner?

Assuming you can scan at blazing speeds you still have the time-consuming business of unrolling or unfolding your drawings, feeding them into the scanner straight and removing them. Then, if you are concerned about scan quality, you need to check the image after scanning. This means zooming in and out, making sure the full extents of the drawing have been captured, possibly rotating (deskewing) the scan, cleaning it, perhaps scanning it again at a more suitable higher or a lower resolution. All of these activities will slow you down. The time it takes to scan a drawing is only a small part of this process.

Finally, the length of time it takes you to get a good scan will depend heavily on the type of drawings you are scanning and the software you use with the scanner. For example, Colortrac's ScanWorks software includes a feature called adaptive thresholding which helps to rapidly clean dirty black and white drawings. If the threshold setting you've chosen is incorrect, you can change it after the fact using a slider bar. The changes you make can be viewed in real time on the screen. There's no need for experimentation and no need to rescan the drawing. This is a major productivity booster if you are dealing with dirty black and white scans.

Do you really need fast scan speed? It matters most to those with high volumes to scan, like scanning bureaus, but is largely irrelevant to CAD users doing one or several scans at a time.

Despite this, it is one of the major determinants of a scanner's price:

• The only difference between Colortrac's c (colour) and more expensive e (express colour) models is colour scan speed.

• The only difference between Contex's HD Base and more expensive HD Plus models is scan speed.

• The only difference between Contex's SD4430, more expensive SD4450 and yet more expensive SD4490 is scan speed.

• The only advertised differences between Graphtec's Base and more expensive Pro models are scan speed and interpolated resolution, although the increased speed is achieved by use of a High Speed mode that decreases image quality.

For more thoughts on scanner speed, see:

NO BULL: Phew! Some issues that need cleaning up! Scan Speed
NO BULL: Scan Speed Part 2 - Contex redefines large format scanner productivity in raw "drawings per hour"

Accuracy

All large format scanners claim accuracies of around 0.1%, and different manufacturers use different conditions to measure accuracy. Even if the scanner is very accurate, the drawing itself may not be, especially if it has been badly treated by folding etc. and has shrunk or stretched in storage.

Note that all scanners are likely to develop accuracy problems and stitching errors over time and if they are moved. CCD scanners in particular should be calibrated from time to time to maintain accuracy.

See Large format scanner accuracy and calibration.

Scan Quality

We believe that all the scanners in our large format scanner comparison chart, with the possible exception of Graphtec Base models, are capable of creating scans of good enough quality for CAD.

Scan quality is the result of a number of factors including the scanner's technology, the quality of its internal components, its optical resolution, the software supplied with it and even the skill and knowledge of the person using it! All scanners are capable of producing poor quality scans if operated carelessly or with inappropriate settings. We have seen thousands of unusable images, often produced by professional scanning bureaus using high end scanners.

For information on how to create a high quality scan, see our article Creating high quality scans for raster to vector conversion.

Before buying a scanner we recommend that you get test scans done of a typical drawing of your own on a variety of scanners. Does the scanner create a clean, sharp image with all the detail you need? Does it produce distinct text characters? Does it keep close parallel lines separate?

Ultimately what matters is that the scan quality is right for the documents you want to scan.

Upgradeability

The advantage of an upgradable scanner is that you can buy the least expensive option now and upgrade to a better specified model later if and when you require it.

Colortrac SmartLF m (monochrome) models are upgradable to colour c or e models. Colortrac SmartLF c (colour) models are upgradeable to e (express colour) models, which have four times faster colour scanning speeds. Colortrac upgrades are supplied via email.

Contex HD Base models can be upgraded to Pro models, which have faster colour scanning speeds. Contex upgrades are supplied as an upgrade card, which is plugged into an external slot in the Base scanner to turn it into a Pro.

We do not suggest that you buy Graphtec Base models because they do not have a High Quality mode. However, Graphtec Base models can be upgraded to Pro models which have a High Quality mode, High Speed mode (allows faster scanning but only with loss of scan quality) and increased interpolated resolution. Graphtec upgrades are supplied as replacement data boards which need to be installed inside the scanner.

If you upgrade to a more expensive scanner because you want faster colour scanning, remember you'll only get faster scanning if your PC is capable of accepting and processing data faster. Don't upgrade on the basis of increased interpolated resolution - all interpolated resolution does is increase the size of a scan without adding to captured drawing detail or improving image sharpness.

Energy Star Compliance

Energy Star is a labelling program designed to identify and promote energy efficient products. At present, Colortrac Ci 40, Colortrac Gx+, Contex XD, Contex SD, Graphtec and Image Access scanners are Energy Star compliant.

On some literature issued by Contex and their distributors you will see reference to Contex HD scanners as being "Energy Saver compliant". There is no such standard as "Energy Saver" - it is a Contexism.

System Requirements

Make sure that the scanner will work with the PC you intend to run it on. In particular, check the amount of RAM it requires (the more you have the better), the connection it needs (most scanners need USB 2 - USB 1.1 won't work) and make sure it supports your operating system.

All the scanners in our large format scanner comparison chart can be run on Windows but you need to check with individual manufacturers for the versions of Windows that are supported.

If you have an Apple Mac your options are more limited. Colortrac and Graphtec scanners don't support Macs. Contex HD scanners can be run from a Mac but need to be run using Contex's Photoshop plugin or third party software.

The only scanners that are OS independent and that can be run from a Windows PC, Mac or Unix system with equal facility are the Image Access WideTEK range.

Networkability

In our experience, most people assume that their large format scanner will be networkable, allowing it to be shared between all the PCs in an office. In fact, large format scanner networkability is a new development.

The only true network scanners - i.e. scanners that can be connected to a network via ethernet - are Colortrac Ci 40 and Gx+ scanners, Graphtec IS/CS scanners, the Contex HD4230i and the Image Access WideTEK range.

Graphtec GB do not promote their scanners' networkability as they say it is slow. We have not tested it. Of the other scanners above, we have networked the Colortrac Ci 40 and the WideTEK 36. Scanning with the Colortrac, we found that scanning over our network was up to two times slower than scanning via USB.

However speed is definitely not an issue with the WideTEK. The WideTEK contains a powerful internal processor and transmits scans to the receiving PC via a fast 1Gb connection. In house speed tests between a WideTEK and "traditional" scanners have indicated that the WideTEK is considerably faster than other scanners, particularly when scanning large colour files. The WideTEK can be run directly from a touch screen built into the scanner or can be run from a PC connected to the scanner via the network. It can be run from any standard internet browser.

Most Contex scanners cannot be connected to a network via ethernet. However, they are networkable. They must be connected to a host PC via USB, but can then be shared over the network via the host PC using free WIDEsystemNET drivers that are supplied for this purpose. We found Contex's networking very easy to use, and two to four times slower than scanning direct via USB.

Weight and Dimensions

Scanner size and weight are most important if you need a portable scanner or if you work from a cramped office.

The most portable scanner is the Shapemakers Deskan, as it comprises an A4 / A size scan head with guides. If you need a portable sheet-fed scanner, the Contex XD2490 is the lightest A1 / D size scanner at 35.5 lbs (16.1 kg). Colortrac Ci 40 scanners are the lightest A0 / E size scanners at 49 lbs (22 kg).

If you have a cramped office, the smallest A0 / E size scanners are the Image Access WideTEK 36 (43" wide) and the Graphtec CSX300 (43.3" wide). The WideTEK is very heavy and will need to be placed on its own floorstand, however the Graphtec scanners are light enough to be placed on a desk or work surface.

Another handy A0 / E size scanner for a cramped office is the Colortrac Ci 40. At 48.5" it is slightly wider than the WideTEK or the Graphtec, but it has a unique paper feed where documents are fed into the front of the scanner, fed around a roller, and ejected out of the front of the scanner. The Ci 40's front paper exit is particularly handy when it is placed on a workspace with a wall behind it and with no real space for a drawing exiting from the rear of a scanner to go.

Floorstand

Do you need a floorstand? How much extra does it cost?

Most buyers opt for a floorstand because it is more practical than placing the scanner on a desk or table top. It minimises the installed footprint of the scanner and lets you easily access the front of the scanner at a convenient height. In addition, many scanners are big and heavy and it would be hard to find a desk or table large and sturdy enough to hold them.

Floorstands come in different varieties. For example, most manufacturers now offer both a standard floor stand and a floor stand designed to place the scanner above most popular makes of printer, thus saving floor space.

Contex and Graphtec scanner stands include a paper catch basket - a bag or tray attached to the floorstand to catch drawings after they have been scanned. Colortrac charge extra for a paper catch basket, but a paper catch basket isn't strictly necessary, especially if the scanner has the ability to hold a drawing after scanning rather than drop it on the floor.

Most scanners are supplied without floor stands, which are an optional extra. Exceptions include the Image Access WideTEK range and Graphtec scanners (USA only).

Scanning Software

Most of the scanners in our large format scanner comparison chart include TWAIN or WIA drivers. This means that they can be used directly with any software that supports TWAIN or WIA, such as Photoshop and Scan2CAD.

Other than TWAIN/WIA drivers, scanning software functionality is broadly divided into two categories: Scan to file and scan to copy. Scan to file is for scanning to various formats like TIFF, JPG and PDF. Scan to copy is for making the scanner function like a large format photocopier, in conjunction with a printer. Most scan to copy software supports a particular range of printers and may or may not include colour matching so that the colour of the print is the same as the colour of the original scanned document.

Most scanners are supplied with free but basic scan to file and scan to copy software. More comprehensive scan to file and scan to copy software is available for all scanners from the manufacturers or from third party suppliers such as SCP and Paradigm.

If your drawings are generally clean and good quality basic scan to file software will probably do everything you need. However if you are dealing with dirty drawings, the scanning software you use can seriously affect your productivity. With a dirty drawing you will probably need to edit the scan settings several times before you get the best possible scan and you will probably also need tools like adaptive thresholding that are not available in all scanning software.

Useful features to look for in scan software are:

• Does the software save to the format(s) you want?
• Is it easy to zoom around the scanned image to quickly check that the scan is OK?
• Is there a rotate feature so you can quickly rotate a drawing that you've accidentally scanned the wrong way up?
• Is there an auto paper size facility?

If you are dealing with dirty drawings, additional features to look for are:

• What scan settings does the software include to help tidy dirty drawings? (e.g. Adaptive thresholding.)
• When choosing scan settings do you have to guess the correct settings or can you view the effects of changes you make in real time?
• If you scan a drawing with unsuitable scan settings, do you have to rescan the drawing with new settings or can you change the settings after the fact, without having to rescan?

If you are intending to use the scanner as part of a large format copying system:

• Make sure the software supports your printer.
• Does the software support colour matching? (Unlikely to matter in a CAD environment but important in a repro or photo environment where the colour of the print needs to match the colour of the original scanned document.)

It's our opinion that Colortrac's ScanWorks scanning software is the most productive scanning software there is because it only requires a drawing to be scanned once and changes to settings can be made in real time. Read our ScanWorks review here.

Contex's Nextimage software is a big improvement over their previous WideImage software because, like ScanWorks, it allows you to change settings in real time. However unlike ScanWorks, it works on a preview-rescan principle. First, you make a preview scan. You adjust the scan settings until the preview scan looks good, then you make a final scan using the adjusted scan settings. The problem with this is that it is not time efficient (the paper has to pass through the scanner three times instead of only once) and - more worryingly - the final scan does not necessarily reflect what you see in the preview. Read our Nextimage review here.

In our opinion, Graphtec's Scanning Master 21+ software is not as productive as Colortrac's ScanWorks or Contex's Nextimage. Settings cannot be changed in real time unless you use the Rocker Mode, which we found difficult to use quickly with any precision. Read our Scanning Master 21+ review here.

(Note: We believe that Image Access' Scan2Edit software now works in a similar fashion to Colortrac's ScanWorks software but we have not yet seen it to confirm.)

The best way to see how easy it is to produce a scan with given software is to get a demo of the scanner you're intending to buy. Bring one of your own drawings and see how easily the salesman manages to produce a good scan. Be sure to take the scan home and to inspect it closely as it may look fine until you zoom into it and view the details.

Warranty

Many manufactureres or distributors are now including on-site warranties with their scanners to give them an edge over the competition. In the event of a problem you will be visited by an engineer. The warranty includes all non consumable-parts and labour.

If there is no on-site warranty, the standard warranty is a one or two year return to base warranty that includes non-consumable parts and labour. This means that while the repair is free, you have to pay to transport the scanner to a place where it can be repaired (usually the manufacturer or distributor's premises) or pay for someone to come to your premises to fix it. In addition, under the terms of a return to base warranty you may be required to return the scanner to base in the original packaging. This means you need to keep and store the scanner's box. Scanner boxes are HUGE.

Most manufacturers offer extended paid-for warranty options. There are two basic types of extended warranty, a swap-out warranty where you get a replacement scanner while yours goes off to be repaired and an on-site warranty - a visit to your premises by an engineer. The advantage of a swap-out warranty is that it usually costs less and lets you get on with scanning while your scanner is being fixed - engineers who visit may not be able to visit next day, and when they do visit they may not be able to fix the problem immediately. The disadvantage of a swap-out warranty is that you still have the hassle of packing and unpacking your scanner and the replacement scanner, and as with a return to factory warranty you may be required to keep the scanner's original box.

In addition to standard warranties, Image Access scanners include a unique diagnostics service. As a networked scanner run via a browser it is possible for outside engineers to interrogate your Image Access scanner directly should anything go wrong.

Disclaimer

Whereas every care has been taken in compiling the information on this page, no legal responsibility can be accepted for any possible errors or omissions. If you discover an error or omission, please contact us and let us know, so we can address the issue. Thank you.

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